Analytical Chemistry: A Literary Approach - ACS Publications

Chemistry for Everyone

Analytical Chemistry: A Literary Approach Charles A. Lucy Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada; [email protected]

Students, like most people, actually get most of their understanding of science not from school but from mass media—television, movies, and novels. Certainly it is the resonation with fiction that gets many scientifically apathetic people excited about breakthroughs in cloning and in the search for extraterrestrial life. A number of recent articles in this Journal have discussed the advantages of using fictional works (1–6 ) to introduce various chemistry topics. Similarly, the works of Sir Arthur Conan Doyle and Dorothy Sayers have been used to introduce forensic chemistry (7 ). Fictional literature is also rife with examples of analytical chemistry, many of which are surprisingly detailed and accurate. Others are pure technobabble. This paper provides an anthology of references to descriptions of analytical chemistry techniques from history, popular fiction, and film. Students find such references amusing and interesting. Further, the fictional descriptions can serve as a focal point for discussions of a technique’s true capabilities and limitations. Biblical and Historic Analytical Chemistry Heftmann (8) and Ettre (9) contend that the first reference to the use of ion exchange is the biblical account of Moses’ years in the desert after fleeing Egypt. There are some bitter lakes in the area south of where the Suez Canal now exists. When Moses arrived in Ma’rah after crossing the Red Sea, he found the water undrinkably bitter (10): And he cried unto the Lord; and the Lord shewed him a tree, which he cast into the waters, and the waters were made sweet.

The logical explanation of this miracle is that Moses sweetened the water by ion exchange. This reference provides a lively example by which to introduce the concept of ion exchangers and their use for water softening and deionization. Irving (11) has identified Babylonian and biblical references to fire assays. Fire assays are quantitative gravimetric methods in which metals are determined in ores and metallurgical products by extracting and weighing them in the metallic state. The sample of ore or metal is mixed with a flux containing mainly lead oxide, with smaller amounts of sodium carbonate, potassium carbonate, borax, silica, potassium nitrate, and organic materials such as flour (12, 13). Upon fusion in a muffle furnace at 苲1050 °C, precious metals collect in the pool of lead formed by reduction of the lead oxide by the flux. Base metals within the sample end up in the slag. Subsequent oxidation of the lead button allows separation of the lead from the precious metals. The bead of precious metals, called a dore, is then weighed. Cuneiform tablets tell of the King of Babylon complaining to the Egyptian Pharaoh Amenophis the Fourth (1375–1350 B.C.E.) (11): Your majesty did not look at the gold which was sent me last time … after putting them in the furnace this gold was less than its weight.

Likewise, from the Old Testament, in Zechariah (14 ): And I will put this third into the fire, and refine them as one refines silver, and test them as gold is tested.

might be viewed as an oblique reference to fire-assaying gold.1 Probably one of the most enthusiastic chemical analyses ever recorded was Archimedes’ (287–212 B.C.E.) determination of the purity of the golden wreath2 (15). King Hieron had commissioned the crafting of a golden wreath to thank the gods for a recent victory. The completed wreath possessed the same weight as the gold supplied for its construction, but the king suspected that the smith had substituted some silver for an equal weight of gold. The king commanded Archimedes to determine whether the wreath was pure gold. However, Archimedes could not subject the wreath to any type of destructive chemical analysis, since the consecrated wreath was a sacred object. One day, while pondering this question, Archimedes stepped into his bath. Upon lowering himself into the water, he noted that water flowed over the edge! And the deeper he lowered himself into the water, the more water flowed over the edge! He was so overjoyed by this observation that he jumped from the tub and ran home naked shouting eureka, eureka (I have found it!). What Archimedes had discovered, of course, was the law of displacement. To assay the wreath, he took a lump of gold and a lump of silver, each possessing the same weight as the wreath. He immersed each of these into a jar full of water, and determined the amount of water displaced by each. Upon repeating this exercise with the wreath, he determined that the amount of water lost was greater than that for the lump of gold and less than that for the silver. In this manner Archimedes provided the king with a nondestructive assay of the purity, or rather impurity, of the sacred wreath. The Roman Gaius Plinius Secundus (Pliny the Elder, 23–79 C.E.) reported an early colorimetric spot test for the purity of verdigris in his encyclopedic work Historia Naturalis. Verdigris (vert de Grèce: green of Greece) is copper acetate, and was used by the Romans as medicine. Pliny describes a procedure based on the reaction of copper with tannic acid as follows (9): The adulteration of verdigris that is most difficult to detect is done with shoemakers’ black [iron sulfate].… Shoemakers’ … is also detected by means of papyrus previously steeped in an infusion of plantgall [containing tannic acid] as this when smeared with genuine verdigris at once turns black.

Ettre (9) notes that this procedure is close to the spot tests developed in the 1930s. Analytical Chemistry in Classical Mysteries Probably the most studied fictional chemist is Sherlock Holmes (16–19). Holmes’s biographer, Dr. Watson, introduced Holmes as a “first-class chemist”, although “his studies are very desultory and eccentric, but he has amassed a lot of out-of-the-way knowledge which would astonish his professors” (20). Previous

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studies of Sherlockian chemistry (16–18) provide extremely entertaining reading, as do the series of scientific problems presented in the form of Sherlock Holmes mysteries (6 ). This discussion will focus only on what Graham (16 ) describes as Holmes’s forte, analytical organic chemistry. For indeed, Holmes (21) Busied himself all the evening in an abstruse chemical analysis which involved much heating of retorts [distillation flasks] and distilling of vapours, ending at last in a smell which fairly drove me out of the apartment.

And as with all things, Holmes’s chemical studies are typified by intense concentration and energy (22): I was thinking of turning in and Holmes was settling down to one of those all-night chemical researches which he frequently indulged in, when I would leave him stooping over a retort or a test-tube at night, and find him in the same position when I came down for breakfast.

But what were the subjects of Sherlock Holmes’s chemical researches? Not surprisingly they are primarily of a forensic nature. Gerber (7) used Holmes’s interest in blood detection as an introduction to modern forensic science. In A Study in Scarlet, the first of the Sherlock Holmes stories, Holmes announces the discovery of a new test for blood, as depicted in Figure 1 (23): [The chemistry laboratory] was a lofty chamber, lined and littered with countless bottles. Broad, low tables were scattered about, which bristled with retorts [distillation flasks], testtubes, and little Bunsen lamps, with their blue flickering flames. There was only one student [young Holmes] in the room, who was bending over a distant table absorbed in his work. At the sound of our steps he glanced round and sprang to his feet with a cry of pleasure. “I’ve found it! I’ve found it!”… he shouted, running towards us with a test-tube in his hand. “I’ve found a reagent which is precipitated by hæmoglobin, and nothing else. “Now, I add this [drop] of blood to a litre of water.… The proportion of blood cannot be more than one in a million.” … He threw into the vessel a few white crystals, and then added some drops of a transparent fluid. In an instant the contents assumed a dull mahogany colour, and a brownish dust was precipitated to the bottom of the glass jar.…“The old guaiacum test was very clumsy and uncertain.… Now, we have the Sherlock Holmes test, and there will no longer be any difficulty .”

The guaiacum test was an important test for blood in the late 19th century. In this test, guaiacum, a tree resin, is added to an aqueous solution of suspected blood. Addition of hydrogen peroxide then yields a blue color if blood is present. However, the sensitivity of this method was highly variable, presumably due to the purity of the guaiacum (19). To produce the color change observed by Holmes, an acid would be necessary to increase the oxidation state of the heme, and a reagent would need to be oxidized. Redmond (17 ) suspects that this description is of a variant of the Sonnenschein test, in which the suspected stain is treated with a saturated solution of sodium tungstate that has been acidified with acetic acid. The sensitivity of this test, about 50 parts per million, was comparable to that of the guaiacum test. Most tests for blood are based on the peroxidase-catalyzed oxidation of a reagent to form a characteristic color. The test using phenolphthalein is still in active use and provides a good classroom demonstration (24). In this test the oxidation of 460

Figure 1. Sherlock Holmes discovers a new test for blood. “’I’ve found it! I’ve found it,’ he shouted.” From A Study in Scarlet (1887). Illustration by George Hutchinson for Ward, Lock & Bowden.

the phenolphthalein to a pink color has a sensitivity of about 0.2 ppm of blood. In The Copper Beeches, Holmes again makes explicit, although somewhat enigmatic, reference to his analytical chemistry research when he states “Perhaps I had better postpone my analysis of the acetones [sic]” (25). But to what does Holmes refer? Redmond (17) points out that in the late 19th century the terms “ketones” and “acetones” were used interchangeably. Thus, Holmes may have been referring to analyzing a group of ketones. However, given Holmes’s interest in blood, Redmond prefers the hypothesis that Holmes was actually referring to analyzing “acetone bodies” (acetone, acetoacetic acid, and β-hydroxybutyric acid) in blood. These acetone bodies are altered by the level of adrenaline in blood. Adrenaline levels are, of course, elevated when a person is under stress or undergoing severe physical exertion. Thus, this is truly a forensic analysis worthy of Sherlock Holmes. Today, there are a multitude of approaches available to analyze adrenaline (epinephrine), including HPLC (26–28), capillary electrophoresis (29), and electrochemical (30–32) and spectroscopic (33–34) methods. Thus, the determination of adrenaline makes a good literature search problem. The chemistry behind another of Holmes’s analyses, shown in Figure 2, is more difficult to identify (35). Holmes was seated at his side table clad in his dressing gown and working hard over a chemical investigation. A large curved retort was boiling furiously in the bluish flame of a Bunsen burner, and the distilled drops were condensing into a two-litre measure.… He dipped into this bottle or that, drawing out a few drops of each with his glass pipette, and finally brought a test-tube containing a solution over to the table. In his right hand he had a slip of litmus-paper. “You come at a crisis, Watson,” said he. “If this paper remains blue, all is well. If it turns red, it means a man’s life.” He dipped it into the test-tube and it flushed at once into a dull, dirty crimson. “Hum! I thought as much!” he cried.… “A very commonplace little murder,” said he.

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Figure 2. “Holmes was working hard over a chemical investigation.” From The Naval Treaty (1892). Illustration by Sidney Paget for the Strand Magazine.

That Holmes’s investigations were at the state of the art is unquestionable, given his use of the Bunsen burner so soon after its invention. Many common poisons such as yellow phosphorus, cyanide, chloroform, phenol, and chloral hydrate3 can be distilled from acid solution without decomposition (36 ). However, I have found no report of litmus paper being used in the detection of any of these agents. Thus there remains a mystery in the chemistry within the stories of Sherlock Holmes. Agatha Christie’s The Mysterious Affair at Styles does not deal explicitly with analytical chemistry. However, it would be remiss not to note the ingenious use by Southward et al. of the details of the strychnine poisoning of Mrs. Inglethorpe, a wealthy elderly widow. They used this example to develop a problem set dealing with solubility products, salting out, neutralization, and weak bases (1). In Dorothy L. Sayers’s The Documents in the Case (37), George Harrison is an elderly expert in edible fungi. One day, Harrison is found grotesquely sprawled over the bed in his country cottage. The apparent cause of death is accidental ingestion of muscarine from the poisonous fly agaric mushroom. However, Harrison’s son does not believe that his father could have made such an amateurish mistake when it came to mushrooms. This suspicion led eventually to the belief that Harrison was poisoned with synthetic (racemic) muscarine. There have been excellent discussions (2, 38) of Sayers’s use of a polarimeter to solve this mystery. However, her description of Sir James Lubbock, the Home Office Analyst, captures the essence of analytical chemists so well that it bears repeating: Sir James Lubbock unlocked another cupboard, and produced a large heavy instrument, rather like a telescope fixed to a stand.… “At the further end of the instrument is a thin plate of the semi-transparent mineral, tourmaline.… In the ray of ordinary light, the vibrations take place in all directions, but when passed through a slice of tourmaline they are confined to one plane, and the light is polarised.… Now at this end,

near the eyepiece, is a second slice of tourmaline, which can be rotated, and which is called the analyser. “Now, if… I place the solution of an optically active substance between the two slices of tourmaline, the light will … come through. But if… the substance should be optically inactive— if, for example, it should turn out to be a synthetic product, prepared from inorganic substances in the laboratory—then it will not rotate the beam of polarized light. The darkness will persist. “I think we’ll have the control solution first, if you don’t mind.” … Sir James settled down to his experiment with comfortable deliberation. He place the cylinder containing the solution in the polariscope, adjusted the eyepiece and looked. … “So far,” he said dryly , “the laws of Nature appear to hold good.” With maddening deliberation, the analyst set the first cylinder carefully to the side and took up the other.… He put the cylinder into the polariscope and looked. There was a pause. Then a grunt. Then his hand came up, feeling for the adjustment. There was another pause and an exclamation of impatience. Then his eye was jerked back from the eyepiece and his head peered round to examine the exterior of the instrument.… Sir James’s hand came round again, feeling, this time, for the cylinder. He took it out, held it up, looked at it and replaced it with great care. He looked again, and there was a long silence. Then came Sir James’s voice, queer and puzzled. “I say , Waters. There’s something funny here. Just have a look, will you?” Waters … took Sir James’s place before the instrument. He moved the cylinder back and forth once or twice and said … “either it’s a suspension of the laws of Nature, or this muscarine [from Harrison’s stomach] is optically inactive.” “You know what that means.” Then Sir James said slowly: “The man was murdered. My God, this is a lesson to me, Waters. Never overlook anything. Who would have thought—? But that’s no excuse. I shall have to—I must verify it first, though. Do the preparations again.”

More recently, in Patricia Cornwell’s Body of Evidence, medical examiner Kay Scarpetta uses a similar approach to determine that an apparent accidental death was actually a suicide (39). In Clouds of Witness, Lord Peter Wimsey’s manservant Bunter, states “Of course, we aren’t analytical chemists” (40). However, in Strong Poison (41), Bunter’s analysis of arsenic in samples of fingernails and hair from the true murderer proves that he is an adept amateur: The distilled water was already bubbling gently in the flask. … “You will perceive that the apparatus is free from all contamination.” “I see nothing at all.” “That, as Sherlock Holmes would say, is what you may expect to see when nothing is there.” Bunter … delicately dropped the white powder into the wide mouth of the flask. … And presently, definitely , magically , a thin stain began to form in the tube where the flame impinged upon it. Second by second it spread and darkened to a deep brownish-black ring with a shinning metallic center. “It’s either arsenic or antimony .… The addition of a small amount of solute chlorinated lime should decide the question.” The stain dissolved out and vanished under the bleaching solution. “Then it’s arsenic.”


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Foster (38) identifies Bunter’s procedure as Marsh’s test. In this method arsenic is reduced by hydrogen generated using metallic zinc in sulfuric acid. The arsine formed is heated as it passes through a delivery tube; and upon cooling, elemental arsenic deposits as a shining mirror. This procedure was favored in poisoning cases, since as little as one microgram arsenic could be detected. Sayers’s inclusion of a blank determination at the beginning of the passage demonstrates a clear understanding of analytical chemistry procedures. Sayers again refers to Marsh’s method in The Unpleasantness at the Bellona Club (42). An elderly man has passed away under questionable circumstances in Lord Peter Wimsey’s gentlemen’s club. In order to resolve this unpleasantness, Lord Peter seeks to have a stain on the gentleman’s shoe analyzed by Sir James Lubbock, the well-known analyst … received his visitor in his laboratory , where he was occupied in superintending a Marsh’s test for arsenic. “D’ye mind just taking a pew for a moment, while I finish this off?” Wimsey took the pew and watched, interested, the flame from the Bunsen burner playing steadily upon the glass tube, and the dark brown deposit slowly forming and deepening at the narrow end. From time to time the analyst poured down the thistle-funnel a small quantity of a highly disagreeablelooking liquid from a stoppered phial; once his assistant came forward to add a few more drops of what Wimsey knew must be hydrochloric acid. Presently, the disagreeable liquid having all been transferred to the flask, and the deposit having deepened almost to black at its densest part, the tube was detached and taken away, and the burner extinguished. “Enough of the stuff to kill an elephant. Considering the obliging care we take in criminal prosecutions to inform the public at large that two or three grains of arsenic will successfully account for an unpopular individual, it’s surprising how wasteful people are with their drugs.”

Unfortunately, while other analyses are pivotal to the story, Mrs. Sayers does not detail how they are performed. So we do not know how the chemical formula of the paint and varnish on the shoe was determined, or how it was determined that—–no, I should let you discover that for yourself. Modern Analytical Techniques in Best Sellers The use of analytical techniques in literature did not end with classic literature. Rather, as so well phrased by Michael Slade in Evil Eye (43), Gone are the days of Sherlock Holmes solving cases by triumphs of logic, and prodding Jack Webb seeking “Just the facts, ma’am.” The magnifying glass gave way to fingerprint lasers used in conjunction with cyanoacrylate and vacuum metal deposits, to scanning electron microscopes that magnify particles hundreds of thousands of times, to gas chromatographs or mass spectrometers that separate complex compounds into their components, and to DNA analysis.

Thus the modern best sellers, particularly mysteries, are rife with modern analytical instrumentation. Many times these instruments are simply mentioned in passing. However, there are a number of surprisingly detailed descriptions of analytical instrumentation. A number of these are given below. The Andromeda Strain, by Michael Crichton (44 ), is a modern technothriller classic, which recounts the actions of four top scientists trying to deal with a plague that came to 462

Earth on a returning space probe. The book jacket states that the events “reveal a mix of foresight and foolishness, innocence and ignorance. Everyone involved shows moments of great brilliance … and of unaccountable stupidity.” This statement is prophetic in that it not only describes the action recounted in the book, but also the accuracy of the analytical chemistry described. In Chapter 20, the scientists are trying to identify the pathogen using an arsenal of modern analytical techniques, including an atomic spectrometer about which Crichton gives a detailed description: The spectrometer employed in Level V was the standard Whittington model K-5. Essentially it consisted of a vaporizer, a prism, and a recording screen. The material to be tested was set in the vaporizer and burned. The light from its burning then passed through the prism, where it was broken down to a spectrum that was projected onto a recording screen. Since different elements gave off different wavelengths of light as they burned, it was possible to analyze the chemical makeup of a substance by analyzing the spectrum of light produced. In theory it was simple, but in practice the reading of spectrometrograms was complex and difficult. No one in this Wildfire laboratory was trained to do it well. Thus results were fed directly into a computer, which performed the analysis. Because of the sensitivity of the computer, rough percentage compositions could also be determined. Burton placed the first chip, from the black rock, onto the vaporizer and pressed the button. There was a single bright burst of intensely hot light; he turned away, avoiding the brightness, and then put the second chip onto the lamp. Already, he knew, the computer was analyzing the light from the first chip. He repeated the process with the green fleck, and then checked the time. The computer was now scanning the self-developing photographic plates, which were ready for viewing in seconds. But the scan itself would take two hours—the electric eye was very slow. Once the scan was completed, the computer would analyze results and print the data within five seconds.

While this description is apt for an atomic spectrometer circa 1960s, the results reported in Chapter 22 are not. The printout of the spectrometer analyses erroneously includes results for hydrogen, helium, boron, carbon, nitrogen, oxygen, and halogens. This error is particularly glaring as the conclusions of the analysis were The black rock contained hydrogen, carbon and oxygen, with significant amounts of sulfur, silicon, and selenium, with trace quantities of several other elements. The green spot, on the other hand, contained hydrogen, carbon, nitrogen, and oxygen. Nothing else at all. The two men found it peculiar that the rock and green spot should be so similar in chemical makeup. And it was peculiar that the green spot should contain nitrogen, while the rock contained none at all. The conclusion was obvious: the “black rock” was not rock at all, but some kind of material similar to earthly organic life. It was something akin to plastic.

These results prompt the scientists to question whether the plague was just an accidental event, or whether it was the first step of an alien invasion. Thus, these results are pivotal to the story, but the analytical chemistry is flawed. It is an interesting exercise to have the students investigate in what manner the report results are incorrect, and by what alternative means the required



information should have been obtained. This discussion allows the opportunity to introduce combustion techniques that, while widely used in industry, are generally ignored in analytical chemistry courses. Chapter 22 of The Andromeda Strain also contains detailed descriptions of X-ray crystallography and of the preparation of samples for electron microscopy by microtoming. In his most recent novel, The Lost World, Micheal Crichton reveals that the creators of Jurassic Park had also established a second colony of dinosaurs. The scientists exploring this site are equally as well equipped as the Wildfire laboratory (45): Inside, the trailer was fitted out with gray upholstery and much more electronic equipment. It was divided into sections, for different laboratory functions. The main area was a biological lab, with specimen trays, dissecting pans, and microscopes connected to video monitors. The lab also included biochemistry equipment, spectrometers, and a series of automated sampleanalyzers. Next to it there was an extensive computer section, a bank of processors, and a communications section. All the lab equipment was miniaturized, and built into small tables that slid into walls, and then bolted down.

Clive Cussler’s novel Sahara (46 ) provides a more detailed description of a mobile laboratory and the instrumentation within it. In Sahara, an unknown pollutant is causing a red tide algal bloom off the African coast, which threatens the earth’s oxygen supply. It has been determined that the source is somewhere along the Niger River, but the local governments are hostile to any environmental investigations. Cussler’s manly hero, Dirk Pitt, must covertly sail up the Niger to determine the source of the pollutant and eradicate it before the earth is doomed. Fortunately, Dirk Pitt has modern analytical chemistry on his side: If Pitt had dreamed of pursuing high performance, style, comfort, and enough fire power to take on the American sixth fleet, he found it in the boat. … One look at her sleek, refined lines, the brute size of her engines, and incredible armament, and Pitt was sold. Down in the spacious interior, Rudi Gunn sat in the middle of a small but highly customized laboratory that was planned by a multidisciplined team of scientists that included highly sophisticated, compact versions of instruments developed through NASA for space exploration. The lab was not only set up to analyze water samples but to telemeter the accumulated data via satellite to a team of NUMA [National Underwater and Marine Agency] scientists working with computer data bases to identify complex compounds. Gunn, a scientist from his toes to thinning hairline, was oblivious to any danger outside of the bulkheads of the elegant boat. “Looks complicated,” said Pitt as he stepped around the cabin, studying the sophisticated equipment that was packed together from deck to ceiling. “What function do these instruments serve?” [Gunn] “Okay, to answer your question. There are three key elements to our search approach. The first requires an automated micro-incubator. I use this unit to expose a tiny sample of river water into vials containing red tide samples we obtained off the coast. The micro-incubator then optically monitors the growth of the dinoflagellates. After a few hours the computer gives me an indication of how potent the concoction and how rapid the growth of the little buggers. A little play with numbers and I have a reasonable estimate of how close we’re

coming to the source of our problem.” Gunn moved around Pitt to a pair of square box-like units about the size of small television sets but with doors where the screens would have been. “These two instruments are for identifying the nasty glob, as I call it, or a combination of globs that’s behind our problem. The first is a gas chromatograph/mass spectrometer. To put it concisely, I merely take vials of river water samples and place them inside. The system then automatically extracts and analyzes the contents. The results are interpreted by our on-board computers.” “What exactly does that tell you?”, asked Pitt. “It identifies synthetic organic pollutants, including solvents, pesticides, PCBs, dioxins, and a host of other drugs and chemical compounds. This baby, I hope, will home in on the chemistry of the compound that’s mutating and stimulating the red tide.” [Pitt] “What if the contaminant is a metal?” [Gunn] “That’s where the inductively coupled plasma/mass spectrometer comes in,” said Gunn, gesturing at the second instrument. “Its purpose is to automatically identify all the metals and elements which might be present in the water.”

Students are very lively in their discussion about whether Dirk has the necessary equipment to save the world, and it generates many excellent questions regarding real-world environmental analysis. Cussler’s novel Night Probe! (47 ) also contains a brief reference to analytical methodology. Dirk Pitt must recover a copy of the North American Treaty lost in 1914 when a train derailed owing to a bridge collapse. The fate of billions of dollars in oil revenue and the separation of Quebec from Canada (!) lies in the balance. And once again, analytical chemistry techniques provide critical clues. The four of them manhandled the steel scrap [from the bridge] into a corner of a small warehouse. There the lab people used electric saws with moly steel blades to cut off samples which were soaked in a solution and cleaned by acoustics. Then they filtered away to different laboratories to begin their respective analytic specialities. It was four in the morning when McComb conferred with his assistants and approached Pitt in the employees’ lounge. “I think we have something interesting for you,” he said, grinning. “How interesting?” Pitt asked. “We’ve solved the mystery behind the Deauville-Hudson bridge collapse.” McComb motioned for Pitt to follow him into a room crammed with exotic-looking chemistry equipment. … “We put specimens of [the sample from the bridge] under a scanning electron microscope, which shows us the characteristic electrons in each element present. The results revealed residue from iron sulfide.” “What does it all mean?” “What it means, Mr. Pitt, is that the Deauville-Hudson bridge was cleverly and systematically blown up.”

Scanning electron microscopy (SEM) is widely used for forensic analysis (48). The tremendous magnification (100,000×) possible with SEM yields lateral resolution down to 3 nm (although day-to-day forensic work rarely requires magnifications greater than 10,000×). This makes possible forensic applications such as the study of lines drawn by writing media, of minute features on suspected counterfeit coins, and of the cystolithic hairs of cannabis and other plants. Further,


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the wide depth of field of SEM (several orders of magnitude greater than for light microscopes) enables three-dimension imaging of the sample, which is valuable in forensic applications such as identifying bitemarks and determining the direction of incised wounds caused by blades. However, Cussler’s statement that SEM “shows us the characteristic electrons in each element present” actually refers to an energy-dispersive X-ray analysis spectrometer (EDX). EDX commonly accompanies SEM instruments. In EDX, the electron probe beam causes excitation of core electrons, much as X-rays do in X-ray fluorescence spectroscopy. When the excited atom decays it emits an X-ray. The energy of this X-ray is characteristic of the particular energy levels of the upper and lower electronic states, and thus of a particular element. In general, EDX is useful for elements with atomic numbers greater than 11 (Na). The element specificity of EDX, coupled with the spatial resolution of SEM, is extremely useful in forensic work. For instance, it can be used to determine if a suspect has recently fired a gun. Gunshot particles are removed from the suspect’s hands using a piece of adhesive tape. Using SEM–EDX, the tape is then examined for particles that may have originated from the bullet primer. Such particles are characterized by their size, shape and elemental composition (lead, antimony and barium). SEM-EDX can also be used to detect black powder (KNO3, S, and C in a 75:15:10 ratio), as might have been used in 1914. However, the characteristic residue for black powder is potassium. Furthermore, EDX cannot determine the speciation of an element. Nonetheless, it is interesting to ask students how the analyst might infer the speciation of the sulfur (answer: solubility). For most conventional explosives, gas chromatography with chemiluminescent detection is used (49). For an explosive to be reported as present, the peak has to be confirmed on three differing polarity columns. If possible, additional confirmation is obtained using gas chromatography–mass spectroscopy or thin-layer chromatography. Using these systems, low nanogram levels of organic explosives can be detected. Another popular author who has made repeated explicit references to analytical instrumentation is Dick Francis, the master of the equestrian cliffhanger. In Francis’s novel Proof (50), someone has highjacked tanker trucks loaded with scotch and red wine and is selling the scotch grain whisky as scotch malt whisky. The private detective hired to stop the highjackings required a consultant who could identify individual scotches by taste. Enter Tony Beach, a recently widowed wine merchant. Little did Tony know he would soon be tasting danger in addition to the scotch blends. Fortunately, along with his formidable courage, Tony also had some knowledge of analytical chemistry. “Did you have a profile of that load [of scotch]?” [Tony Beach] asked. “A what? [Tony] “Um … its composition. What it was blended from. You could get a detailed list from the distiller, I should think. The profile is sort of chemical analysis in the form of a graph … it looks like the skyline of New York. Each different blend shows a different skyline. The profile is important to some people … the Japanese import scotch by profile alone, though actually a perfect-looking profile can taste rotten. Anyway, profiles are minutely accurate. Sort of like human tissue typing … a lot more advanced that just a blood test.” 464

“The Customs people probably have [a profile] already ,” I said. “They’ll have the equipment. A gas chromatograph.”

Scotches are produced by fermentation of malted barley or grains followed by distillation. After distillation, the whisky matures in oak casks for at least 3 years and often more than 12 years. The resultant product contains several hundred known components (congeners) including alcohols, aldehydes, ketones, acids, esters, phenols, and nitrogen- and sulfur-containing compounds. The major congeners are n-propanol, isobutanol, and isoamyl alcohol. Brand authenticity is determined using this higher alcohol profile along with methanol (51–53). These are readily determined by gas chromatography using a polar stationary phase such as Carbowax 20M. Additional confirmation of authenticity can be obtained based on the phenolics extracted from the cask during maturation. These phenolics can be determined by high-performance liquid chromatography on a reversed-phase column (53). A second Dick Francis novel, Straight (54 ), also makes reference to gas chromatographic analysis. The hero of this story is Derek Franklin, a 34-year-old steeplechase rider. He is contemplating the end of his riding career after a horse stepped on (read “crushed”) his ankle after a fall at the last fence at Cheltenham. Now he learns that his much older, and much loved, brother has been killed in a freak accident. In his own words, “I inherited my brother’s life. Inherited his desk, his business, his gadgets, his enemies, his horses and his mistress. I inherited my brother’s life, and it nearly killed me.” Overnight Derek is thrust into a situation where he must solve the mysteries of where one and a half million dollars in diamonds has disappeared and why his brother’s 5-year-old stallion Dozen Roses has suddenly started winning races after a disastrous season as a 4-year-old. In this latter problem, analytical chemistry aids Derek. [Veterinarian] “Do you know what a metabolite is?” [Derek] “Only vaguely.” [Veterinarian] “It’s what’s left after some substance or other has broken down in the body.” [Derek] “So what?” [Veterinarian] “So”, he said reasonably , “if you find a particular metabolite in the urine, it means a particular substance was earlier present in the body . Is that clear ?” [Derek] “Like viruses produce special antibodies, so the presence of the antibodies proves the existence of the viruses?” [Veterinarian] “Exactly ,” he said, apparently relieved I understood. “Well, the lab found a metabolite in Dozen Roses’ [the horse’s] urine. A metabolite known as benzyl ecgonine.” [Derek] “Go on,” I urged, as he paused. “What is it the metabolite of?” [Veterinarian] “Cocaine ,” he said.4

Tests for many illicit drugs, such as marijuana and heroin, seek the metabolite, and not the drug itself. And indeed, benzoyl ecgonine is the primary metabolite of cocaine. Benzoyl ecgonine can be detected in human urine for several days after the cocaine was taken. Federal regulations dictate that gas chromatography–mass spectrometry be used for confirmation of urine samples that yield a positive response from the immunoassay screening procedure (see below). Typical analytical procedures (55) involve performing a liquid–liquid or solid-phase extraction on the urine sample and then forming a nonpolar derivative such as n-propyl or



trimethylsilyl. The derivatized sample is separated on a 5% diphenyl/95% dimethylpolysiloxane or 100% dimethylpolysiloxane column and detected by single-ion monitoring mass spectroscopy. Detection limits for the gas chromatography– mass spectroscopy procedures range from 5 to 50 ng/mL. A sample, however, is considered “positive” only if the concentration of benzoyl ecgonine in a urine sample exceeds 150 ng/mL. Students easily grasp the ramifications of a “positive”, and thus this example helps clarify the distinction between “limits of detection” and “limits of quantification”. However, just because a metabolite is observed, does that necessarily indicate drug abuse? For instance, many of the metabolites from drug abuse are the same as would be observed after legal use of prescription opiates or even ingestion of poppy seeds in food (56 ). Such problems are illustrated in Patricia Cornwell’s Cause of Death (68, p 131) and in an episode of Seinfeld (57) in which Elaine’s drug test shows opiates. The amusing paper “Can a Poppy Seed Food Addict Pass a Drug Test?” (56 ) addresses the issue of false positives due to ingestion of poppy seeds and provides a lively forum for discussion of the concept of “false positives and negatives”. Assay methods are largely overlooked in analytical chemistry courses. Sadly, these methods are also only given passing reference in literature. Dick Francis’s novel Comeback (58) includes a reference to immunoassay. Peter Darwin, a young First Secretary in the Foreign Office makes an unplanned return to Gloucestershire, scene of the long-buried memories of his childhood. There he unintentionally becomes the guardian angel to a veterinarian who someone is out to destroy professionally. In Chapter 3 Peter Darwin stands a lonely vigil through the night in the veterinarian’s hospital, which had been burned down the day before by the unknown assailant. I read another article, this time about enzyme-linked immunosorbent assay , a fast antibody test for drugs in racehorses. It was the only reading matter of any sort within sight. I had a readaholic friend who would read bus timetables if all else failed. Hewett and Partners didn’t use buses.

In fact, at about the time Comeback was published there was an article on the use of ELISA for testing racehorses for drugs in the United States Trotting Association’s magazine Hoof Beats (59). When administered to horses, opiates stimulate running, suppress the sense of pain, and delay the onset of fatigue. Thus, they have been attractive to unscrupulous trainers for more than 100 years. ELISA tests are particularly well suited for race testing, as they require only a small amount of blood, are extremely sensitive, and are easily automated. In 1991, there were ELISA tests available for detection of 40 drugs in racehorses A similar passing reference to radioimmunoassays is given in Patricia D. Cornwell’s novel All That Remains (60). Five young couples have disappeared in the Williamsburg, Virginia, area over a two-year period. In each case the bodies are not discovered until well after the disappearance, by which time all that remains are bones and fragments of clothing—and a Jack of Hearts. Dr. Kay Scarpetta, Virginia’s Chief Medical Examiner, is a member of the team trying to solve the crimes. In Chapter 9 Scarpetta is discussing the forensic challenges of these cases. “There was some red tissue left, muscle. That’s enough for testing. Cocaine or heroin, for example. We, at least, would have expected to find their metabolites of benzoylecogonine

[sic] and morphine. As for designer drugs, we tested for analogues of PCP, amphetamines.” “What about China White?” [the police investigator] proposed, referring to a very potent synthetic analgesic popular in California. “From what I understand, it doesn’t take much for an overdose and is difficult to detect.” “True. Less than one milligram can be fatal, meaning the concentration is too low to detect without special analytical procedures such as RIA .” Noting the blank expression on his face, I explained, “Radioimmunoassay, a procedure based on specific drug antibody reactions. Unlike conventional screening procedures, RIA can detect small levels of drugs, so it’s what we resort to when looking for China White, LSD, THC .”

Immunoassay methods are capable of measuring picograms of material and are widely used for detecting drugs of abuse. For example, in employee drug-screening programs, immunoassays are used to identify the drug-negative samples (the vast majority) with minimal laboratory effort. Those samples that the immunoassay indicates are drug-positive are analyzed by a confirmatory test such as gas chromatography– mass spectroscopy. In a recent study that screened 50,000 samples, RIA detected 99.1% of the GC–MS-confirmed marijuana (THC) samples, 99.6% of the cocaine positives, and 100% of the opiates (e.g., morphine, codeine), but only 78% of the barbiturates (61). Both GC–MS and immunoassays are featured in Robin Cook’s Harmful Intent (62). In this novel, anesthesiologist Jeffery Rhodes’s career is ruined when he is charged with malpractice after the death of one of his patients. But Rhodes is convinced that the death was actually caused by a toxin in the anesthetic. [Nurse] “So if it was injected along with the [anesthetic], why wouldn’t it show up with the toxicology testing?” [Rhodes] “For two reasons. First, it’s probably introduced in such minute amounts there is very little in the tissue sample to be detected. Second, it’s an organic compound that could hide among the thousands of organic compounds that normally exist in any tissue sample. What’s used to separate all the compounds in a toxicology lab is an instrument called a gas chromatograph. But this instrument doesn’t separate everything cleanly. There’s always overlaps. What you wind up with is a graph featuring a series of peaks and valleys. Those peaks can reflect the presence of a number of substances. It’s the mass spectrograph that actually reveals what compounds exist in a sample.

But later Rhodes starts to suspect that the toxin may be a phytotoxin or tetrodotoxin. [Coroner] “I’d use [toxins] if I were to knock somebody off: they’re a bitch to trace. As to whether you can detect them, I’d have to say yes and no. The big problem is that a very little bit of some of these toxins goes a very long way. They need only a few molecules to do their dirty work. I’m talking nanonano moles. That means our usual old standby, the gas chromatograph, combined with a mass spec, often can’t pick the toxin out of all the other organic compounds floating around in the sample soup. But if you know what you’re looking for, like tetrodotoxin, say, because the deceased dropped dead at a sushi party, then there are some monoclonal antibodies tagged with either fluorescein or a radioactive marker that can pick the stuff up. But I’m telling you, it ain’t easy .”

Toxins range from small molecules such as peptides or complicated organic molecules (e.g., paralytic shellfish poisons) to proteins. Toxins can indeed be extremely poisonous.


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For instance, the lethal dose for humans of the botulinum A toxin produced by the bacterium Clostridium botulinum (a few picomoles) is almost a thousand times lower than that of the VX nerve gas. Since toxins are either very polar (e.g., shellfish toxins) or very high molecular weight (e.g., botulinum A toxin), gas chromatography cannot be used even with derivatization. Instead, liquid chromatography is most suitable. More specifically, liquid chromatography coupled with mass spectroscopy has been used in recent years for the detection and identification of plant and fungal toxins, insect poisons, bacterial toxins, reptile and amphibian venoms, and marine toxins and venoms (63). However, further improvements in LC–MS (e.g., nano- and pico-electrospray) are still needed to determine extremely toxic proteins such as botulinum A at low levels. But as the coroner in Harmful Intent stated, “it ain’t easy”. As a result, bioassays and related tests remain the method of choice for some toxins, such as the C. botulinum toxins. For botulinum toxins, mouse lethality is still the most sensitive and reliable method. However, in view of the expense, lack of specificity, and questionable morality of such tests, considerable effort is being expended to develop immunoassay methods (64). Such tests provide earlier detection than mouse bioassays and require no pretreatment of the sample. However, they are not yet commercially available and may give false-negative results because of antigenic variations within botulinum toxins of the same type. Dr. Kay Scarpetta brings many more analytical techniques into play in trying to catch a sadistic rapist-murderer in Post-Mortem (65). During the post-mortem examination of the latest victim, she employs a new technique: The laser we acquired last winter was a relatively simple device. In ordinary light sources, atoms and molecules emit light independently and in many different wavelengths. But if … light of a certain wavelength is impinged upon it, an atom can be stimulated to emit light in phase. I was … watching … through a pair of amber-tinted goggles. Directly below me was the dark shape of [the latest victim’s] remains, the covers from her bed open but still underneath her. I stood in the darkness. Instantly spitting from the wand was a rapidly flashing synchronized light as brilliant as liquid chrysoberyl. We explored inches of the suffused flesh at a time. Tiny fibers lit up like hot wires and I began collecting them with forceps. … In addition to its usefulness in finding fibers and other trace evidence, it reveals various components of perspiration that fluoresce like a neon sign when stimulated by a laser. Theoretically, a fingerprint left on human skin can emit light and may be identified in cases where traditional powder and chemical methods will fail.

This passage quite accurately describes the use of laserexcited fluorescence for detection of latent fingerprints (66 ). The “light as brilliant as liquid chrysoberyl ” suggests that an argon ion laser (all lines in blue-green) is used, as is typical for this application. The argon laser light passes through an optical filter and illuminates about a 10-cm2 area of the article. The examination is conducted in a darkened room, with the investigators wearing filtered goggles to block the reflected laser light but allow transmittance of the fluorescence.

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The passage continues: As [the technician] began probing her neck, a constellation of tiny stars popped out like shards of glass hit by headlights on a dark street. … We’d found the same glitter scattered over the bodies of the first three strangling victims. … So far, the strange residue had not been identified beyond determining that it was inorganic.

But, what is the “glitter”? In Chapter 4, they have an idea how to approach the problem: “We’ll give scanning electron microscopy a shot at it, hopefully determine if the elemental compositions or infrared spectrums are the same as those in the residues…in the previous cases.”

But in Chapter 10: Scanning electron microscopy wasn’t so sure. Sodium borate, sodium carbonate and sodium nitrate, for example, all came up as flat-out sodium in SEM. The trace amounts of the glittery residue came up the same way—as sodium. … In other words, all that glitters is not borax.

Finally in Chapter 15: “If [the murderer is] washing with borax soap, I suspect he’s doing so at work.” “We’re sure it’s borax?” [the FBI investigator] asked. “The labs determined it through ion chromatography .5 The glittery residue we’ve been finding on the bodies contains borax. Definitely.”

Borate can be determined by ion-exclusion chromatography using 0.1 M fructose in the eluent (67 ). The alteration of the acid dissociation constant of borate by the polyol is an interesting example of complexation and acid–base equilibria. Thus, this quotation offers the opportunity to discuss not only ion chromatographic methods (e.g., why not analyze borate by anion exchange?), but also classical equilibria. Patricia Cornwell offers a more detailed description of scanning electron microscopy in Cause of Death (68): The next morning, I [Kay Scarpetta] made evidence rounds, and my first stop was the Scanning Electron Microscopy lab where I found [the] forensic scientist… sputter-coating a [sample]. … I watched her mount the sample on the platform, which would next go into a vacuum chamber of glass so it could be coated by atomic particles of gold. “Good morning,” I said. She turned around from her intimidating console of pressure guages, dials and digital microscopes that built images in pixels instead of lines on video screens.

A murder had occurred in Dr. Scarpetta’s car, and the scanning electron microscope was about to make a startling discovery about dirt samples left in the car: [The forensic scientist] moved to another digitalized scope, turned on the monitor, and it filled with a black universe scattered with stars of different sizes and shapes. Some were a very bright white while others were dim, and all were invisible to the unaided eye. … We stared at what could have been a scene from inside an observatory. Metal spheres looked like threedimensional planets surrounded by smaller moons and stars. “That’s what came out of your car,” [the analyst] let me know. “The bright particles are uranium. Duller ones are iron oxide, like you find in soil. Plus there’s aluminum, which is used in just about everything these days. And silicon, or sand.” “Very typical for what someone might have on the bottom of his shoes,” I said. “Except for the uranium.”



The uranium becomes a significant clue to the mystery, but “We need to know which isotope of uranium we’re dealing with”. Therefore, Scarpetta took the sample to the University of Virginia, where she knew a nuclear physicist: Most remote to all of this was the low background counting room. Built of thick windowless concrete, it was stocked with fifty-gallon canisters of liquid nitrogen, and germanium detectors and amplifiers, and bricks made of lead. The process for identifying my sample was surprisingly simple. [The nuclear physicist], wearing no special protection other than lab coat and gloves, placed the [sample] into a tube, which he then set inside a two-foot-long aluminum container containing the germanium crystal. Finally, he stacked lead bricks on every side to shield the sample from background radiation. Activating the process required a simple computer command, and a counter on the canister began measuring radioactivity so it could tell us which isotope we had. This was all rather strange to see, for I was accustomed to arcane instruments like scanning electron microscopes and gas chromatographs. This detector, on the other hand, was a rather formless house of lead cooled by liquid nitrogen, and did not seem capable of intelligent thought.

Nonetheless, much later the “formless house of lead” did provide the needed information: I found [the nuclear physicist] in the low background counting room again, sitting before a computer screen displaying a spectrum in black and white. … These vertical lines here indicate the energies of the significant gamma rays detected. One line equals one energy. But most of the lines we’re seeing here are for background radiation…even the lead bricks don’t get rid of all of that. … If you look here on this energy spectrum…it looks like this characteristic gamma ray on the spectrum is for ——”

You didn’t actually think I would give it away, did you? Scarpetta also offers some explanation of DNA fingerprinting by electrophoresis (65, Chapter 13): DNA is the microcosm of the total person, his life code. Genetic engineers in a private laboratory in New York had isolated the DNA from the samples of seminal fluid I had collected. They snipped the samples at specific sites, and the fragments migrated to distinct regions of an electrically charged surface covered with a thick gel. A positively charged pole was at one end of the surface, a negatively charged pole at the other. “DNA carries a negative charge,” I went on, “Opposites attract.” The shorter fragments traveled farther and faster in the positive direction than the longer ones did, and the fragments spread out across the gel, forming the band pattern. This was transferred to a nylon membrane and exposed to a probe. “I don’t get it,” [the reporter] interrupted. “What probe?” I explained, “The killer’s double-stranded DNA fragments were broken or denatured, into single strands. In more simplistic terms, they were unzipped like a zipper. The probe is a solution of single-stranded DNA of a specific base sequence that’s labeled with a radioactive marker. When the solution, or probe, was washed over the nylon membrane, the probe sought out and bonded with complementary single strands— with the killer’s complementary single strands.” “So the zipper is zipped back up?” she asked. “But it’s radioactive now?” “The point is that his pattern can now be visualized on X-ray film,” I said. “Yeah, his bar code. Too bad we can’t run it over a scanner and come up with his name,” [the FBI investigator] dryly added.

“Everything about him is there,” I continued. “The problem is the technology isn’t sophisticated enough yet to read the specifics, such as genetic defects, eye and hair color, that sort of thing. There are so many bands present covering so many points in the person’s genetic makeup it’s simply too complex to definitively make anything more out of it than a match or a nonmatch.”

Prizes, Erich Segal’s chronicle of three extraordinary individuals as they vie for the Nobel Prize, also contains a short description of gel electrophoresis (69) “Why don’t we get the electrophoresis under way” … Sandy nodded, and the two men used pipettes to place droplets of silver-stained gel into the small squares at the end of what looked like a miniature, clear plastic bowling-alley . They then placed the closed tray into a small tank and turned on the electrodes, which activated the migration of particles.

However the most detailed description of DNA fingerprinting comes from Michael Slade’s Evil Eye (43), in which Detective Nick Craven of the Royal Canadian Mounted Police (RCMP) finds himself charged with the brutal murder of his own mother. A blood stain has been found on Nick’s red serge. The DNA typing procedure used by the RCMP has four steps. … Step One saw the sample in each tube digested with proteolytic enzymes, centrifuged and washed to extract pure DNA. From the fume hood where this occurred, [the technician] carried the tubes to the left side of the lab where the DNA in each tube was digested with HaeIII. This “restriction enzyme” scans DNA for sequences it recognizes and cuts the strands at those sites. Different people’s DNA cuts at different places, producing different combinations of fragment lengths. Step Two saw the lengths sorted by a method called electrophoresis. Agarose is a jelly with pores through which DNA lengths can pass. The tubes of cut-up samples to be matched are loaded into slots at the “origin end” of the slab of gel. Like a racetrack, the slots feed parallel lanes. When electric current is applied across the gel, the samples migrate through the slab away from the origin end. The smaller the fragment, the faster it migrates, so when the electric current stops, the DNA pieces in each lane halt in separate bands. Step Three saw the fragment bands transferred from the gel slab to a nylon membrane by Southern blotting. From the Examination Room, [the technician] carried the membrane to the radioactive Hot Room. There, placed in a bottlelike tube and bathed with “probe”, the membrane stewed in a Robbins incubator. A DNA probe is a short piece of DNA tagged with a radioactive label. The genetic sequence of the probe seeks out and only binds to complementary sequences on the membrane fragments. Once this binding was done, [the technician] washed excess probe off the membrane and overlaid it with a sheet of X-ray film. He then stored both layers in a freezer at ᎑70 degrees C. There, radiation from the probe-marked bands registered bar codes on the X-ray film. Since the bands to which a probe binds vary from person to person, each bar code is a “genetic fingerprint”. Running the film through a processor produced this autoradiogram. Step Four saw the autorads go … for computer work. A computer scanned the bar codes to determine the size of each band. The probability of two samples both binding for the probe at that point was statistically known, so multiplying the chance of each autorad having a match by the chance of the other four—1/50 × 1/9 × 1/8 and so on—produced the probability of Lanes six and ten matching on all five autorads. “One in one hundred billion,” said [the technician]. “The


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Chemistry for Everyone odds the DNA in the blood on the cuff didn’t come from [the victim] are one in one hundred billion .” “Could your tests be wrong?” asked [the detective]. “Nothing in science is ever black and white,” said [the technician]. “Every new test developed goes through an initial stage of exaggerated infallibility , followed closely by doubt.

Robin Cook’s Acceptable Risk (70) tells the saga of neuroscientist Edward Armstrong. The story begins with Armstrong pursuing his pet theory that the “devil” in Salem in 1692 resulted from consumption of grain tainted with a mold that produced a hallucinogenic drug. However, the efficacy of the mold’s hallucinogen quickly leads to Edward’s modifying the compound to generate a new generation of antidepressants. This novel incorporates many aspects of development of pharmaceuticals. Robin Cook also displays a familiarity with modern analytical instrumentation. [Post-Doc] “The new capillary electrophoresis system which we’ve been using for micellar electrokinetic capillary chromatography is being temperamental again. Should I call the rep from Bio-rad?” “I’ll take a look at it”, [Edward] said … and wound his way over to the chromatography unit. [Visitor] “What the hell is that?” “It’s a relatively new separation technology,” Edward said. “It’s used to separate and identify compounds.” [Visitor] “What makes it new?” “It’s not entirely new,” Edward said. “The principles are basically the same as conventional electrophoresis, but the narrow diameter of the capillaries precludes the necessity of an anticonvection agent because heat dissipation is so efficient.” [Visitor] raised his hands in mock self-defense. “Enough”, he said. “I give up. You’ve overwhelmed me. Just tell me if it works.” “It works great,” Edward said.

Later, in trying to separate the alkaloids isolated from the mold— [Post-Doc] “How do you want to separate the alkaloids? With organic solvents?” “Let’s use capillary electrophoresis,” Edward said. “If necessary we can go to micellular [sic] electrokinetic capillary chromatography.” [Post-Doc] “Should I run a crude sample like I did with the mass spec?” “No,” Edward said. “Let’s extract the alkaloids with distilled water and precipitate them with a weak acid. … We’ll get purer samples, which will make structural work easier.”

Gradually they elucidate the structure of the hallucinogen from the mold. [Edward] “We’ve started on determining the compounds structure.” [Friend] “How on earth can you figure that out?” “The first step was to get an idea of molecular weight with standard chromatography,” Edward said. “Then we broke the molecule apart with reagents that rupture specific types of bonds. Following that we try to identify at least some of the fragments with chromatography, electrophoresis, and mass spectrometry .” … “That’s our nuclear magnetic resonance machine,” Edward said proudly. “It’s a crucial tool with a project like this. It’s not enough to know how many carbon atoms, hydrogen atoms, oxygen atoms, and nitrogen atoms there are in a compound. We have to know the three-dimensional orientation. That’s what this machine can do.” … 468

“Let me show you one other machine,” Edward said. … It was a hopeless tangle of electronic equipment, wires, and cathode tubes. “It’s an X-ray defraction [sic] unit. … It complements what we do with the NMR.”

These passages from Acceptable Risk can be used to initiate discussion of structure identification. Tom Clancy and Steve Pieczenik’s Op-Center is designed to provide rapid tactical response to situations and people threatening national security. In Tom Clancy’s Op-Center: Games of State (71), Paul Hood, the director of the Op-Center, flies to Europe to demonstrate a new analytical technique, and Tom Clancy demonstrates that his awareness of high technology extends into analytical chemistry: The first object he removed was a silver box roughly the size of a shoebox. It had an iris-like shutter in the front, and an eyepiece in the back. “Solid-state laser with viewfinder,” he said helpfully. The second object resembled a compact fax machine. “Imaging system with optical and electrical probes ,” he said. “What?” Lang asked as he watched attentively. “In a peanut shell,” Stoll said, “what we call our T-Bird. It directs a fast laser pulse at a solid-state device, generating laser pulses. These pulses only last—oh, about one hundred femtoseconds, which is a tenth of a trillionth of a second. … What you get are tertahertz oscillations that wriggle around between the infrared and radio wave area of the spectrum. What that gives you is the ability to tell what’s inside or behind something thin—paper, wood, plastic, almost anything. All you have to do is interpret the change in the waveforms to tell what’s on the other side. And coupled with this baby”—he patted the imaging device—“you actually get to see what’s inside.” “Like an X-ray ,” Lang said. “Only without the X ’s”, said Stoll. “You can also use it to determine the chemical composition of objects—for example, the fat in a slice of ham.” “When our lab first developed this technology,” Hood said, “we were trying to find out how to tell what kinds of gases and liquids were inside bombs. That way, we could neutralize them without getting near them.

Terahertz or T-ray laser pulses have in fact demonstrated the ability to scan objects within packaging (72, 73). This is possible because materials such as metals, semiconductors, and superconductors have spectral resonances in the terahertz region, whereas nonmetallic materials including plastic and paper packaging do not. In T-ray imaging, spectral resonances are observed as oscillations at the absorption frequency. As remarkable as this technology is, Clancy and Pieczenik unfortunately exaggerate its capabilities: “Could I borrow your wallet” he asked. Lang reached into the breast pocket of his jacket and handed his wallet to the scientist. Stoll placed it on the opposite side of the desk. Then he went over and pressed a green button beside the white button. The silver box hummed for a moment, and then the faxlike device began to scroll out a piece of paper. … When the paper stopped moving, Stoll retrieved it and took a quick look at it. He handed it to Lang. “Is that your wife and kids?”, Stoll asked. Lang looked down at the slightly fuzzy black-and-white image of his family . “Remarkable.”

Occasionally an author’s inclusion of technical detail unintentionally adds to the drama of the novel. For instance, in



Robin Cook’s Brain (74 ), radiologist Dr. Martin Philips tries to determine the cause of a rash of bizarre mental breakdowns in female patients. As the novel approaches its climax Philips becomes frantic as he realizes his new-found love was shortly to be the scourge’s next victim. Glancing at his watch Philips noticed that time was slipping rapidly away. In one-half hour he [had to solve the mystery]. What Philips had to know was what was radioactive deoxyglucose used for. Philips descended the clinic stairs to the library … arriving at the library totally out of breath. “Deoxy-glucose,” he panted. “I need to look it up. Where?” [Librarian] “I guess you could start with the Chemical Abstract.”

The thought of starting a Chemical Abstracts search less than one-half hour before a deadline certainly sends shivers down this chemist’s spine. Analytical Chemistry in Science Fiction Probably the best known analytical instrument of fiction is the Star Trek tricorder. However, remarkably little functional detail about tricorders is given within the episodes or fan documentation. Star Trek technical manuals indicate the term “tricorder” refers to its three primary functions: sensing, computing, and communications (75). It is a portable device developed by Starfleet R & D and was issued to starship crew members. The analytical capabilities of the tricorder were achieved by 235 mechanical, electromagnetic, and subspace devices mounted about the internal frame and imbedded in the casing as conformal instruments. Approximately half of the sensors are clustered at the forward end of the tricorder for directional readings. These devices have a field of view lower limit of 1⁄4 degree. The remaining sensors are omnidirectional, taking measurements of the surrounding space. A second deployable hand sensor contains an additional 17 highresolution devices for detailed spatial scanning. The tricorder uses readings from multiple sensors to generate images and numerical readouts of use to the crew member. But what types of sensors are being used? Obviously, many of the sensors (particularly the directional ones) are spectroscopic in nature. But what other types of sensors might the tricorder also contain? The text of the Classic Episodes provides some clues (76 ). For instance, passive electromagnetic sensors are most certainly used to detect energy outputs in Errand of Mercy. The tricorders also contain magnetic (The Enemy Within) and radiation (Miri) sensors. However, what kinds of sensors are used to determine atmospheric gases such as oxygen, nitrogen, and traces of argon, neon, and krypton (The Galileo Seven), chemical contamination (Miri), or silicon life (The Devil in the Dark) remains a mystery. In an explicit example of life imitating art, the TR-107 Tricorder Mark 1 has recently been marketed by Vital Technologies Corp. (Bolton, ON, Canada) for educational and field applications (77 ). True to its fictional predecessor, this instrument possesses multiple sensors and has data-logging capabilities and a “Stardate” clock. Sensors include temperature, atmospheric pressure, EMF, light, and color. The colorimeter is based on spectral reflectance of light from six light-emitting diodes (LEDs). The tricorder can also be connected to a pH probe. However, science fiction does not always foreshadow science fact. In Flare (78), Roger Zelazny and Thomas T.

Thomas describe technology that was new in 2018 C.E. as6 Newer equipment which was now on the market combined the separate procedures into an integrated stream under computer control. The new way involved staining and spooling the genetic material into ever-flowing fluid channels which were capillaried through silicon control blocks no wider than a human hair.

In reality, the first paper to report performing capillary electrophoresis on a chip was published in 1992 (79), and the first DNA separation on a chip was reported in 1996 (80). Similarly, the movie Gattaca (Columbia Pictures Corporation, 1997) is set in a genetically pure future, where naturalborn and physically flawed Vincent (Ethan Hawke) is barred from his dream of space travel by his “In-valid” DNA code. To pursue his dream he assumes the identity of a genetic better. However, he must conceal his true inferior identity. Police in the Gattaca future carry hand-held sensors that instantaneously analyze the DNA in snips of hair, drops of blood, or urine in order to expose the genetically inferior. Therefore, Vincent must scrub himself daily to rid his body of loose hairs, skin flakes, and anything that might reveal his true identity. He must keep pouches of genetically superior urine for impromptu urine tests; he must keep sachets of blood glued to his fingertips for daily blood tests; and he must sprinkle genetically superior skin and hair samples everywhere he goes to keep up the ruse. But can he conceal his true identity when the director of the space agency is murdered and everyone in the space program is a suspect, including Vincent? But more important to chemistry students, is the question whether such hand-held DNA sensors are really that futuristic. A recent article reviewed a number of approaches currently being developed for hand-held DNA sensors (81). My personal experience has been that students find the cystic fibrosis DNA sensor of Susan R. Mikkelsen of the University of Waterloo (82) a fascinating high-tech application of the basic principles of voltammetry and partitioning that they have covered. Notes 1. Irving also asserts that Ezekiel 22:20–22 (“As men gather silver and bronze and iron and lead and tin into the furnace, to blow the fire upon it in order to melt it”) also refers to fire assay. 2. The distinction of a wreath rather than a crown is important. Because the wreath was consecrated, and thus sacred, it could not be subjected to destructive analysis. 3. Chloral hydrate is the oldest of the hypnotic (sleep-inducing) depressants. It was first synthesized in 1832. Chloral hydrate takes effect in a relatively short time (30 minutes) and will induce sleep in about an hour. Its sedative effects are heightened by mixing with alcohol, and in the late 1800s it was added to alcohol to form the infamous “Mickey Finns” used by press gangs in seedy dockside bars. 4. Athletes interested in improving their speed should note it was not the cocaine that improved Dozen Roses’ speed. Rather, in Chapter 10: Dozen Roses looked docile to dozy, I thought. … He was a good performer, of that there was no question, but he didn’t at that moment give an impression of going to be a “trot-up” within half an hour. … Was this the young buck who had tried to mount a filly at the starting gate at Newmarket? No, I saw with a sense of shock, he was not. I peered under his belly more closely, as it was sometimes difficult to tell, but there seemed to be no doubt that he had lost the essential tackle; that he had in fact been gelded.


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Chemistry for Everyone 5. Contributed by Hamish Small, the inventor of ion chromatography. 6. Contributed by Jed Harrison, a pioneer of micro-total analysis systems (“lab on a chip”).

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