Chemical world This Week
In Brief A Palo Alto, Calif., company has perfected a method of rapidly measuring drugs and other chemicals in the body fluids. Syva Corp. uses spin labels in its freeradical assay technique 11
Pressure from consumerism and environmentalist groups is persuading detergent makers to drop the use of enzymes in household detergent products 12
Superheavy elements exist, according to preliminary evidence gathered by a team of British scientists. The team believes it has discovered element 112 12
N-acetylglucosamine polymers are effective in speeding the healing of wounds. A commercial product is now ready that may find uses in dentistry, surgery, skin diseases, and burns 13
A new joint research institute, Particulate Solid Research, Inc., has been formed by 15 major chemical and engineering companies 13
February 22, 1971
SPIN LABELS AID ASSAYS Spin labels, until now useful mainly as research tools, are emerging as a novel and convenient means to assay drugs and other chemicals in body fluids. At Syva Corp., Palo Alto, Calif., scientists have perfected a method of rapidly measuring the amount of morphine, a heroin metabolite, and related chemicals in urine down to 10_6M concentration levels. Soon, they will extend the technique to other drugs such as cocaine, barbiturates, and amphetamines. Dr. Edwin F. Ullman, vice president and director of research at Syva, a cooperative venture of neighboring Syntex and Varian, ticks off a number of advantages to the new assay approach which goes by Syva's tradename, FRAT (free radical assay technique). For one thing, screening is rapid. An assay takes less than a minute, costs $1.50 or so a test, and is specific for the chemical being assayed, ruling out the possibility of false positive readings. Dr. Ullman doesn't detail the chemistry of the spin labels beyond saying that they are small molecules incorporating nitroxide radicals. In solution they tumble rapidly, C&EN:
providing characteristic, sharp ESR spectral signals. Last year, the company, which has since changed its name from Synvar Associates, made commercially available a variety of spin labels for use in biological research. In their spin label approach to morphine assay, Dr. Ullman, coworker Dr. Richard K. Leute, and Syva consultants Avram Goldstein and Leonard A. Herzenberg at nearby Stanford University school of medicine, first prepared morphine antibody by injecting morphine, bound to bovine serum albumin, into rabbits. When morphine, spin-labeled at the phenolic hydroxyl position, is added to the antibody preparation, it becomes bound to it, immobilizing the spin label and broadening its ESR spectral signal. But when a liquid, such as urine, containing morphine mixes with the complex, some of the spinlabeled morphine is displaced and the ESR peaks are sharpened. The resulting signal intensity is a direct measure of the morphine concentration in the added solution. The new technique's sensitivity is such that it detects 1 nanogram of morphine in 20 microliters of ur-
Dermot O'Sullivan
The proposed crusade to find a cure for cancer may become a surprisingly controversial issue, depending upon priorities and who will conduct the research crusade 14
Two Kansas University scientists have developed a new process that disinfects water quickly and without affecting its taste 14
Syva's Ullman and Leute using FRAT FEB.
22, 1971 C&EN
11
Chemical world This week ine. That's a sensitivity that is a thousand times greater than is possible with TLC procedures, Dr. Ullman and Dr. Leute claim. "Moreover," they add, "the ability of the method to detect the phenolic glucuronide metabolite of morphine just as readily as it detects morphine itself is a great advantage because it enables us to assay the total urinary excretion of heroin or morphine metabolites and related compounds without the need for preliminary hydrolysis of the sample." DETERGENTS:
Enzymes under pressure Another detergent ingredient—enzymes—is showing definite signs of succumbing under pressure from consumerism and environmentalist groups. There's been no sign yet of a ban on use of enzymes in detergents; and enzyme detergent makers say they still have no doubts about product safety. But they are cutting down on use of enzymes, some producers gradually, and at least one altogether. Reason: declining sales due to bad publicity and consumer confusion of enzymes with the much-maligned phosphate ingredient of detergents. Lever Brothers said last week that it had stopped putting enzymes into its Drive detergent on Feb. 4. Drive was Lever's only enzyme detergent. Enzymes in Drive have been replaced with another stainremover, sodium perborate—an oxygen bleach—Lever tells C&EN. Procter & Gamble, the largest U.S. detergent maker, declined to comment last week on newspaper reports that its Staten Island plant had begun manufacture of enzymeless Tide. But president Howard J. Morgens said there have been indications that an increasing number of housewives prefer enzymeless detergents. "There is a vague confusion in the minds of consumers over questions that have been raised about the safety of enzymes. Regardless of the validity of these questions, when consumer preferences change, we adjust our products in response to the changes," Mr. Morgens said. A spokesman for Colgate-Palmolive said only that the company has been reducing and will continue to reduce enzymes in its detergent products. Perhaps hardest hit will be the companies that supply enzymes to 12 C&EN FEB. 22, 1971
P&G's Howard Morgens
detergent makers. Irving Sollins, president of Novo Enzyme Corp., the largest marketer of detergent enzymes, tells C&EN that, on a tonnage basis, detergent enzymes account for about 50% of the company's worldwide business. Dr. Sollins says consumer concern about enzymes is due to "emotional publicity, especially the hue and cry raised by allergists, and public confusion of enzymes with phosphates. This situation is very peculiar to the U.S.," he tells C&EN. Perhaps the last word on enzymes will issue from the National Academy of Sciences-National Research Council. Last fall the Federal Trade Commission, FDA, the President's Committee on Consumer Interests, and detergent industry representatives requested NAS-NRC to review data on the effects of enzymes. That review may help determine the safety of using enzymes in household detergents. ELEMENTS:
Superheavy ones found Superheavy elements exist, according to preliminary evidence gathered by scientists in England. Although there are theories that predict a region in the periodic table containing very heavy but stable elements, the evidence presented by the British team may be a first indication that man has synthesized these elements. Physicists Amnon Marinov, Christopher Batty, and Tony Kilvington, of the Rutherford High Energy Laboratory, Chilton, and chemists William Newton and Vincent Robinson, of University of Manchester's chemistry department, and John Hemingway, of Universities Re-
search Reactor, Risley, think they have discovered the element with atomic number 112. According to predictions, the element would be related to the periodic group 2B metal, mercury. Dr. Marinov, who is on an extended sabbatical from Israel's Hebrew University, cautions C&EN that the team is not yet certain it has found a superheavy element. In its latest experiments, the team is trying to prepare samples for physical tests that will yield an estimate of the energy of fragments arising from spontaneous fission. But fission counts of about two per day and the difficulty of making thin enough samples from amounts of material weighing about 40 micrograms do not make the task an easy one, Dr. Marinov says. However, recent figures from counts of a particle emission have allowed the team to narrow estimates of the suspected element's half-life to between six months and 500 years. The experiments began with two tungsten cylinders 6 cm. by 6 mm. diameter, which had been bombarded with protons. The tungsten targets, which received doses of about 1018 protons each, were not specially prepared for the current experiments, Dr. Marinov explains. Strongest evidence for the existence of element 112 comes from detection of fission fragments emanating from the prepared samples, Dr. Marinov tells C&EN. a particle emission spectra also suggest the presence of the superheavy element, he adds. Very few isotopes decay by spontaneous fission, a property almost entirely linked with elements heavier than uranium. The scientists say they have observed no spontaneous fission from samples using elements from other periodic table groups, such as gold (group IB) and thallium (group 11 IB). Emission of a particles with an energy of 6.73 m.e.v. suggests the presence of element 112, Dr. Marinov says. However, this physical evidence is not one of the experiment's strong points, he adds. The team tentatively eliminates contamination as a source of the peak because likely elements would have other peaks which the scientists could observe but have not detected. In addition, the peak at 6.73 m.e.v. appears not to decay over a period of 24 days, indicating a long-lived element. These pieces of evidence fit in with predictions for properties of element 112.
