Forensic Science - ACS Publications

17 Forensic Toxicology—The Current State of the Art and Relationship to Analytical Chemistry

Downloaded by UNIV OF TEXAS AT DALLAS on July 15, 2016 | http://pubs.acs.org Publication Date: June 1, 1975 | doi: 10.1021/bk-1975-0013.ch017

BRYAN S. FINKLE C e n t e r F o r H u m a n T o x i c o l o g y , U n i v e r s i t y of U t a h , Salt L a k e C i t y , U t a h

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In general terms, t o x i c o l o g y i s the study and understanding of the harmful e f f e c t s of exogenous substances on living systems. Forensic t o x i c o l o g y i s the p r a c t i c e of t h i s biomedical science i n a medico-legal context. In consequence, f o r e n s i c t o x i c o l o g i s t s are to be found p l y i n g t h e i r p r o f e s s i o n a l e x p e r t i s e and tech-nical skills i n l a b o r a t o r i e s supporting the courts and the general c r i m i n a l and civil j u s t i c e system. Analyses of b i o -logical samples, and other m a t e r i a l s thought to be poisoned, i n order to produce f a c t u a l data from which to i n t e r p r e t the c o n d i t i o n of a poisoned v i c t i m or c r i m i n a l suspect i s the d a i l y f a r e of the F o r e n s i c T o x i c o l o g i s t . Cases as various as d r i n k i n g and/or drugged d r i v e r s , e r r a n t probationers and parolees w i t h serious drug problems, drug involvement i n homicide, grand larceny and other major crimes, assessing p o s s i b l e accident versus s u i c i d e and a d v i s i n g the coroner or medical examiner i n fatal poisonings r e q u i r e high scientific acumen and profession-al maturity. Much of the necessary l a b o r a t o r y work can be r e a l -istically r e l a t e d to a n a l y t i c a l chemistry, but the major p r o f e s s i o n a l aspect i s a h i g h l y d i s c i p l i n e d s p e c i a l t y of medical pharmacology. There are some s p e c i f i c i m p l i c a t i o n s i n the phrase, "State of the A r t , " which may shed some l i g h t and reason on the o f t e n m y s t i f i e d view other s c i e n t i s t s hold of f o r e n s i c t o x i c o l o g y and f o r e n s i c science i n general. I t implies that there i s more a r t than science i n t o x i c o l o g y . T h i s , of course, i s simply not t r u e , although the impression i s c o n s i s t e n t with a small, proud group of p r o f e s s i o n a l s (perhaps l e s s than 300 i n the U.S.A.), who until recent years were closed and communicative j u s t between themselves and only showed t h e i r faces p u b l i c l y via r i d i c u l o u s l y dramatized and innaccurate accounts of t h e i r work i n newspapers and T.V. s e r i e s . The image is f u r t h e r f o s t e r e d by the p a i n f u l s e l f - c o n s c i o u s n e s s stemming from exposure in the charged atmosphere of the court room. Is there any other p r o f e s s i o n i n which p r a c t i t i o n e r s are r o u t i n e l y , a g g r e s s i v e l y cross-examined concerning the d e t a i l s of t h e i r work, q u a l i f i c a t i o n s , experience,

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and even f i t n e s s f o r the job? Every e f f o r t i s o f t e n made to deprecate the s c i e n c e , and i t i s not s u r p r i s i n g that the F o r e n s i c S c i e n t i s t has become perhaps too s e l f - c o n s c i o u s of h i s awesome r e s p o n s i b i l i t y i n the l i f e , l i b e r t y and death of others and aware of h i s l i m i t a t i o n s to f u l f i l l the r o l e . T o x i c o l o g i s t s are not p s e u d o - s c i e n t i s t s , much l e s s warped chemists or c l i n i c a l biochemists, f r u s t r a t e d p h y s i c i a n s , lawyers or p o l i c e o f f i c e r s . But t h e i r h i g h l y s t r u c t u r e d d i s c i p l i n e i s "people-science" and, as such, cannot ignore the demands which go beyond c o l d objectivity. In t h i s i t i s unique. The q u i e t r e v o l u t i o n i n our j u s t i c e system which has taken p l a c e i n the past decade has placed massive weight upon s c i e n t i f i c a l l y developed f a c t s and "Expert Opinion". Forensic science i s no longer a luxury, j u r y - i m p r e s s i v e , window d r e s s i n g f o r the t r i a l attorney's case. I t i s a n e c e s s i t y . Today, no one can be t r i e d f o r drunken or drugged d r i v i n g without evidence of blood a l c o h o l or drug concentration, and i n t e r p r e t a t i o n of those values i n terms of a b i l i t y to s a f e l y operate a motor v e h i c l e . S i m i l a r l y , prosecution f o r use or possession of n a r c o t i c s or i l l e g a l drugs r e q u i r e s s c i e n t i f i c a n a l y s i s and s p e c i f i c i d e n t i f i c a t i o n of the suspect m a t e r i a l . These are j u s t two examples of many which are b r i n g i n g i n t o focus the need f o r high c a l i b e r , t r a i n e d and experienced s c i e n t i s t s i n the f o r e n s i c arena. E f f o r t s to b r i n g f o r e n s i c s c i e n t i s t s together and to c o r pora t e l y develop programs f o r p r o f e s s i o n a l progress and upgrading of standards have been s u c c e s s f u l through the American Academy of F o r e n s i c Sciences and i t s Foundation. The formation of the Federal Law Enforcement A s s i s t a n c e A d m i n i s t r a t i o n , and a l s o the Drug Enforcement A d m i n i s t r a t i o n , has g r e a t l y enhanced r e c o g n i t i o n , and u l t i m a t e l y support, f o r needs i n F o r e n s i c Toxicology. There i s , however, a major gap which has b a r e l y been addressed. The demand f o r t r a i n e d f o r e n s i c t o x i c o l o g i s t s i s i n c r e a s i n g ( s i m i l a r l y f o r c l i n i c a l , environmental and i n d u s t r i a l t o x i c o l o g i s t s ) , but there i s l e s s than a handful of u n i v e r s i t i e s i n the United States o f f e r i n g appropriate education. It should be s t a t e d that there are many w i t h " t o x i c o l o g y " l i s t e d i n t h e i r c a t a l o g s , but what number of graduates are f i t t e d when they leave c o l l e g e to immediately enter the f i e l d and become productive? Precious few indeed. Most current teaching i s s o l e l y academic and an adjunct to pharmacy, pharmacology or biochemistry. C e r t a i n l y the book knowledge i s a v a i l a b l e , but what i s the purpose of a l l the knowledge i f you don't know how to use i t ? F o r e n s i c Science can only house people who know how to apply t h e i r l e a r n i n g . Most f o r e n s i c t o x i c o l o g i s t s p r a c t i c i n g today q u a l i f i e d i n a n a l y t i c a l chemistry or a l i f e s c i e n c e , then g r a v i t a t e d i n t o the f i e l d v i a on-the-job t r a i n i n g and the slow a c c r e t i o n of p r a c t i c a l s k i l l and e x p e r t i s e i n the "school of hard-knocks". I d e a l l y , a f i r m undergraduate t r a i n i n g i n b a s i c s c i e n c e s , p r e f e r a b l y chemistry and p h y s i c s , i s



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required. This should be followed by graduate school education with a major i n pharmacology and a minor i n biochemistry and physiology. Concurrent t r a i n i n g i n laboratory techniques should be emphasized, and, before graduation, a one-year i n t e r n s h i p should be undertaken i n an a c c r e d i t e d f o r e n s i c laboratory. F o r e n s i c t o x i c o l o g i s t s are a very s p e c i a l breed, and they do r e quire s p e c i a l t r a i n i n g . Although i t i s p o s s i b l e to discuss the p r a c t i c e of f o r e n s i c t o x i c o l o g y i n broad, general r e f e r e n c e s , i t i s important to recognize that toxicology i s l o c a l . I t i s l o c a l i n terms of time and p l a c e , and i t i s c o n s t a n t l y changing. We l i v e i n a f a s t moving s o c i e t y , and f o r e n s i c science mirrors the vogues, v a n i t i e s pleasures and abuses of s o c i e t y as no other p r o f e s s i o n does. Drug abuse i s i l l u s t r a t i v e of that f a c t : there are many drugs popular on the West Coast that are r a r e l y seen i n the East, and v i c e versa. Drugs which were a major problem perhaps f i v e years ago have now disappeared, to be supplanted by agents of greater appeal, and u s u a l l y of greater p r i c e . So i t i s with broader t o x i c o l o g y . A c c i d e n t a l or d e l i b e r a t e misuse of pharmaceuticals i s the major cause of poisoning i n the United States, but i n l e s s developed countries i t may be c l a s s i c plant a l k a l o i d poisons or u n c o n t r o l l e d use of p e s t i c i d e s . In t r o p i c a l countries i t i s perhaps snake and s p i d e r venoms. We are concerned with the f o r e n s i c t o x i c o l o g i s t t o d a y — i n the United States. What then are the types of problems, how are they r e s o l v e d , what techniques are used, and what does the immediate f u t u r e hold? There are three major case-load areas i n most f o r e n s i c t o x i c o l o g y l a b o r a t o r i e s . They are cases r e s u l t i n g d i r e c t l y from the i l l e g a l use of drugs - "Drug Abuse", t o x i c o l o g y aspects of broad, c r i m i n a l i n v e s t i g a t i o n s - " P o l i c e cases", and a n a l y t i c a l s t u d i e s i n support of the Medical Examiner t o determine cause-ofdeath - "Post-mortem cases". In a d d i t i o n , many f o r e n s i c l a b o r a t o r i e s undertake to a s s i s t l o c a l h o s p i t a l s and p h y s i c i a n s with c l i n i c a l diagnoses and p a t i e n t care i n emergency poisoning cases or those p a t i e n t s r e q u i r i n g complex drug therapy. Although many h o s p i t a l c l i n i c a l l a b o r a t o r i e s are now developing the s p e c i a l i z e d f a c i l i t i e s and t a l e n t required f o r c l i n i c a l t o x i cology, ( c u r r e n t l y there i s a l s o a mushroom growth of p r i v a t e l a b o r a t o r i e s ) , i n most areas the f o r e n s i c laboratory i s the only a v a i l a b l e s e r v i c e . I t f u l f i l l s a mutual need. The p h y s i c i a n requires r a p i d , s p e c i f i c i d e n t i f i c a t i o n of the agent i n v o l v e d , and advice concerning the seriousness of the p a t i e n t ' s c o n d i t i o n . The t o x i c o l o g i s t r e q u i r e s , and i s able to develop through c l i n i c a l experience, a broad a n a l y t i c a l data and experience base from which to assess drug involvement i n p o l i c e and post-mortem i n v e s t i g a t i o n s . I t i s d e s i r a b l e and necessary that c o l l a b o r a t i o n i n the c l i n i c a l and f o r e n s i c areas continue i f the tax-paying community i s to get the best p o s s i b l e s e r v i c e . Court-issued Probation Orders r e g u l a r l y s t a t e that chemical t e s t i n g must be part of the r e h a b i l i t a t i o n program f o r any p r o -



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b a t i o n e r w i t h a drug abuse problem - j u v e n i l e or a d u l t . Urine samples, taken a t the d i s c r e t i o n of the Probation O f f i c e r at i r r e g u l a r i n t e r v a l s , are analyzed to determine whether the probationer i s a b s t a i n i n g from drug use. A judge may command that a blood or u r i n e sample be obtained immediately from a defendant appearing i n court i f he seems to be i n t o x i c a t e d . This occurs s u r p r i s i n g l y o f t e n ! Analyses are f r e q u e n t l y r e quested f o r inmates of county j a i l s and minimum s e c u r i t y p r i s o n s where a l c o h o l and drug problems are o f t e n rampant. C o n t r o l and treatment of h e r o i n a d d i c t s through methadone c l i n i c s a l s o r e q u i r e s t o x i c o l o g i c a l analyses i n s u r v e i l l a n c e of t h e i r behavior and response to treatment. I t i s not unusual f o r a thousand cases of t h i s type to be submitted each month to a l a b o r a t o r y s e r v i n g an urban community of one m i l l i o n people. 1

In the category of " P o l i c e cases", the t o x i c o l o g i s t s g r e a t e s t load comes from d r i n k i n g and drugged d r i v e r cases. This i s an enormous s o c i a l problem w i t h d i f f i c u l t and demanding a n a l y t i c a l t o x i c o l o g y i m p l i c a t i o n s . These cannot be f u l l y discussed i n t h i s paper. S u f f i c e i t to say that 10,000-15,000 cases annually from a m i l l i o n p o p u l a t i o n i s not unusual. C e r t a i n l y , most i n v o l v e only a l c o h o l and can be e f f i c i e n t l y processed by e x c e l l e n t mechanized or semi-automated methods but those i n v o l v i n g other drugs pose extremely d i f f i c u l t problems. The number and v a r i e t y of drugs and a c t i v e m e t a b o l i t e s to be detected and q u a n t i t a t e d i n perhaps f i v e m i l l i l i t e r s of blood i s l e g i o n , and t o x i c o l o g i c a l l y e f f e c t i v e concentrations are i n f i n i t e s i m a l - n a n o g r a m s / m i l l i l i t e r . To f u r t h e r complicate matters, d e f i n i t i v e i n t e r p r e t a t i o n i s demanded: a m e t a b o l i t e of an antidepressant drug; having sworn to t e l l the whole t r u t h , s t a t e u n e q u i v o c a l l y whether t h i s substance d i d i n f a c t impair the defendant's a b i l i t y to d r i v e . That i s when the f o r e n s i c t o x i c o l o g i s t i s put on h i s m e t t l e . Adequate a n a l y t i c a l p r o cedures and techniques are only now being developed to s a t i s f y t h i s type of case, and y e t strong laws are already i n the s t a t u t e books of most s t a t e s . The r e s u l t i n g dilemma f o r the t o x i c o l o g i s t r e s u l t s from the not uncommon human p r o p e n s i t y to put the c a r t b e f o r e the horse: to promulgate laws to r e g u l a t e a s u b j e c t i v e l y apparent s o c i a l problem without thorough study of needs and p r i o r i t i e s and before the means f o r e f f e c t i v e enforcement have been developed. I t has been determined t h a t , i n some areas, n i n e t y percent of a l l crime i s d r u g - r e l a t e d , whether i t be b u r g l a r y to r a i s e cash to buy drugs, or v i o l e n t crimes p e r p e t r a t e d under the i n f l u e n c e of drugs. A l l these p o l i c e i n v e s t i g a t i o n s now i n v o l v e the t o x i c o l o g i s t . The i n c r e a s e i n these types of cases and the accompanying demand by i n v e s t i g a t o r s and courts f o r prompt s e r v i c e has f o r c e d the a n a l y s t i n t o the f o r e f r o n t of s o p h i s t i c a t e d methodology development which now i n c l u d e s mechanized immunoassays and mass spectrometry. A d d i t i o n a l l y , i



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there i s a myriad of c r i m i n a l cases brought to the l a b o r a t o r y . They range from a d u l t e r a t e d candy given to c h i l d r e n a t Halloween, dead dogs perhaps poisoned i n a neighborhood d i s p u t e , to c h i l d abuse and revenge and s p i t e f u l episodes en f a m i l l e or between once-loving f r i e n d s . There i s no wrath to match that of the scorned l o v e r ! They a l l demand care and a n a l y t i c a l i n g e n u i t y . The Coroner or Medical Examiner i s r e s p o n s i b l e f o r d e t e r mining cause-of-death i n the sudden or unexplained demise of a l l persons i n h i s j u r i s d i c t i o n . The terms of h i s work are l e g a l l y d e f i n e d whether he operates on a s t a t e or l o c a l , county b a s i s . To a s s i s t him he r e l i e s h e a v i l y upon t r a i n e d i n v e s t i gators , f o r e n s i c p a t h o l o g i s t s and of course the t o x i c o l o g i s t . At l e a s t one thousand autopsies per year (many more i n major c i t i e s ) are r o u t i n e i n most Medical Examiner O f f i c e s . The bulk of the cases f o r the t o x i c o l o g i s t are suspected s u i c i d e s , a c c i d e n t a l overdose cases or deaths i n which i t i s important to e s t a b l i s h whether the v i c t i m was taking p r e s c r i b e d m e d i c a t i o n f o r example, a known e p i l e p t i c who was on c h r o n i c a n t i c o n v u l s a n t therapy, a middle aged business executive on drugs to c o n t r o l hypertension or a heart ailment, the c o n t r o l l e d d i a b e t i c and the thousands f o r whom t r a n q u i l i z e r s have become a d a i l y necessi t y . For any of these i n d i v i d u a l s , dying i n an automobile a c c i d e n t , i n t h e i r s l e e p , or f o l l o w i n g sudden c o l l a p s e at work,it i s obviously important to a s c e r t a i n the extent to which t h e i r drug use (or l a c k of i t ) may have c o n t r i b u t e d to the t o t a l circumstance surrounding t h e i r death. There are a remarkable number of people who manage to poison themselves by s e l f - m e d i c a t i o n with m u l t i p l e , apparently harmless over-the-counter drugs or l e f t - o v e r p r e s c r i p t i o n t a b l e t s i n the medicine c a b i n e t . Despite s p e c t a c u l a r advances i n pharmacology and pharmacy and F e d e r a l c o n t r o l , there are too many people poisoned as a r e s u l t of medical mismanagement, pharmaceutical company propaganda, and p u b l i c a d v e r t i s i n g of the l a t e s t c u r e - a l l wonder drug. T h i s f a c t alone i s l i k e l y to keep the f o r e n s i c t o x i c o l o g i s t i n business w i t h i n d e f i n i t e job s e c u r i t y . Samples of blood and organ t i s s u e s taken a t autopsy are r a r e l y i n a p h y s i o l o g i c a l s t a t e when r e c e i v e d f o r a n a l y s i s , and t h e r e f o r e present a p a r t i c u l a r challenge to accomplish c l e a n e x t r a c t i o n of the t o x i c o l o g i c a l agent. Accurate q u a n t i t a t i v e data are o f t e n extremely d i f f i c u l t to o b t a i n i n these cases, and, i n consequence,interpretation of r e s u l t s as to l e t h a l i t y or t o x i c o l o g i c a l s i g n i f i c a n c e w i t h i n a set circumstance surrounding the death g e n e r a l l y r e q u i r e s the d e f t , c a u t i o u s touch of e x p e r i ence. C o l l a b o r a t i v e e f f o r t s to pool and d i s c u s s case experiences by members of the I n t e r n a t i o n a l A s s o c i a t i o n of F o r e n s i c T o x i c o l o g i s t s and l o c a l groups such as the C a l i f o r n i a A s s o c i a t i o n of T o x i c o l o g i s t s and t h e i r counterparts i n Great B r i t a i n and Europe have enormously improved the r e a l b a s i s upon which such o p i n i o n i s founded. A l c o h o l i n combination w i t h other c e n t r a l nervous system f



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depressants, t r a n q u i l i z e r s and n a r c o t i c s are the major o f f e n d e r s . Carbon monoxide i s s t i l l a popular means of s u i c i d e ; and a s p i r i n and antihistamines are p a r t i c u l a r l y common i n c h i l d r e n . A l though these agents g e n e r a l l y present uncomplicated problems, the a n a l y s i s of m u l t i p l e drugs and t h e i r metabolites i n degraded or f r a n k l y p u t r i f i e d t i s s u e r e q u i r e s p e c i a l i z e d methods. Unfortunately, the l a t t e r i s the usual s i t u a t i o n . Methods s e n s i t i v e i n the picogram range are necessary f o r many CNS, h i g h l y l i p i d s o l u b l e , or h i g h l y p o l a r drugs i n c l u d i n g cocaine, t r i c y c l i c antidepressants and p e s t i c i d e s , together w i t h t h e i r a c t i v e metabolites. R e s o l u t i o n of a major pharmacological problem, e.g., t o x i c drug i n t e r a c t i o n or another thalidomide, a p u b l i c h e a l t h c r i s i s , e.g., t h a l l i u m or p o l l u t a n t s i n d r i n k i n g water, proper d i s p o s i t i o n of a w i l l or insurance b e n e f i t , or p i n p o i n t i n g a new drug of abuse may w e l l depend upon the s k i l l s of the f o r e n s i c t o x i c o l o g i s t . Any t o x i c o l o g i c a l a n a l y s i s i n v o l v e s two broad steps; the f i r s t i s e x t r a c t i o n of the t o x i c agent from the b i o l o g i c a l matrix and the second i s i d e n t i f i c a t i o n and q u a n t i t a t i o n of the i s o lated material. There are very few u s e f u l t e s t s which can be a p p l i e d d i r e c t l y to body f l u i d s . Exceptions are u r i n e screening t e s t s f o r s a l i c y l a t e , e t h c l o r v y n o l , and phenothiazine drugs. Most notably, enzyme, r a d i o , and s p i n - l a b e l immunoassay techniques have been developed to determine some n a r c o t i c s and sedative hypnotics i n u r i n e and t h i s has been of immense a s s i s t a n c e i n analyzing the very l a r g e numbers of u r i n e samples r e l a t e d to drug abuse c o n t r o l programs. These methods are r a p i d , extremely s e n s i t i v e and r e q u i r e very l i t t l e sample. Unfortunatel y they are plagued by cross r e a c t i o n s which severely l i m i t their specificity. I f t h i s technique could be extended to plasma f o r a broad range of drugs i t would be a major breakthrough to r a p i d screening of samples from i n t o x i c a t e d d r i v e r s . I t i s a l s o p o s s i b l e to very q u i c k l y screen g a s t r i c lavage samples from overdosed v i c t i m s i n the h o s p i t a l emergency room by chemical i o n i z a t i o n mass spectrometry but t h i s i s not yet common p r a c t i c e . Almost a l l commonly encountered t o x i c agents are organic and t h e r e f o r e the e x t r a c t i o n and i d e n t i f i c a t i o n methods have much i n common w i t h c l a s s i c organic chemical a n a l y s i s . The exceptions are obviously the heavy metals, f o r example, a r s e n i c , l e a d , mercury, thallium,etc.. These inorganics are u s u a l l y i d e n t i f i e d by atomic absorption spectroscopy, although energy d i s p e r s i v e x-ray i s f i n d i n g i n c r e a s i n g a p p l i c a t i o n . The l a t t e r i s r a p i d , r e q u i r e s minimal sample p r e p a r a t i o n , i s non-destructive and combines the a b i l i t y to screen a l a r g e number of elements and simultaneously q u a n t i t a t e those detected. For the organic drugs and poisons however, l i q u i d - l i q u i d e x t r a c t i o n has remained the method of c h o i c e . Use of v a r i o u s organic s o l v e n t s and solvent mixtures to d i r e c t l y e x t r a c t homogenized b i o l o g i c a l samples at appropriate pH, i s the b a s i s of most schemes. Ext r a c t i o n at strong a l k a l i n e , weak a l k a l i n e (pH 8.5) and a c i d pH


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i n t o chloroform w i l l e f f i c i e n t l y i s o l a t e b a s i c drugs, amphoteric d r u g s s u c h as m o r p h i n e , and weak a c i d s s u c h as b a r b i t u r a t e s . Of c o u r s e , many d r u g s a r e n e u t r a l and e x t r a c t a t any pH v a l u e . η-Butyl c h l o r i d e i s a f a v o r e d s o l v e n t f o r many b a s i c d r u g s , and c h l o r o f o r m : i s o p r o p a n o l 4:1 i s b e s t f o r m o r p h i n e and i t s analogues. P r i o r p r o t e i n p r e c i p i t a t i o n may be n e c e s s a r y i n p a r t i c u l a r l y i n t r a c t a b l e s a m p l e s and i o n - e x c h a n g e o r c h a r c o a l a b s o r p t i o n h a v e some a p p l i c a t i o n s . The e x t r a c t e d d r u g s i n t h e s o l v e n t f r a c t i o n s a r e c o n c e n t r a ted b e f o r e f u r t h e r s e p a r a t i o n and i d e n t i f i c a t i o n . Gas chroma t o g r a p h y (GC) and t h i n - l a y e r c h r o m a t o g r a p h y a r e t h e s t a p l e t e c h n i q u e s , and GC a l s o p e r m i t s q u a n t i t a t i o n u s i n g s u i t a b l e i n t e r n a l standards. U l t r a v i o l e t spectrophotometry continues to b e i m p o r t a n t as a q u a n t i t a t i v e method and t h e m a s s i v e f i l e s of a v a i l a b l e r e f e r e n c e d a t a ensure i t s f u t u r e i n t o x i c o l o g y . T h e s e and o t h e r p r o c e d u r e s a r e w e l l r e v i e w e d by J a c k s o n (1) S u n s h i n e (2) and F i n k l e ( 3 ) , and a r e recommended t o t h o s e i n t e r e s t e d i n t h e routine"~methods. The n e c e s s i t y t o s p e c i f i c a l l y i d e n t i f y s u b - m i c r o g r a m amounts o f e x t r a c t e d d r u g s and m e t a b o l i t e s has b e e n r e v o l u t i o n i z e d by t h e a d v e n t o f gas c h r o m a t o g r a p h y - m a s s spectrometry(GC-MS), The demand f o r a n a l y s e s w i t h a h i g h d e g r e e o f a c c u r a c y , p r e c i s i o n and q u a l i t a t i v e s p e c i f i c i t y has become a c u t e i n t h e f a c e of w i d e - s p r e a d d r u g a b u s e and t h e m e d i c a l n e e d t o m o n i t o r p a t i e n t s undergoing complex drug t h e r a p y . C h r o m a t o g r a p h i c methods a r e e m p i r i c a l and do n o t o f t h e m s e l v e s p r o v i d e a s o l u t i o n . They g e n e r a l l y l a c k s e n s i t i v i t y and a d i r e c t r e l a t i o n t o m o l e c u l a r structure. GC-MS i s f a s t , d i r e c t , and v e r y s e n s i t i v e , and t h e spectrum p r o v i d e s a r e s u l t w h i c h puts i d e n t i f i c a t i o n beyond d i s p u t e . C o m p u t e r - a s s i s t e d s y s t e m s a r e now a v a i l a b l e w h i c h embody e x t e n s i v e d r u g r e f e r e n c e l i b r a r i e s and c a n be a u t o m a t i c a l l y s e a r c h e d t o i d e n t i f y unknown s p e c t r a . The f u r t h e r d e v e l o p m e n t o f c h e m i c a l i o n i z a t i o n and mass f r a g m e n t o g r a p h y methods u s i n g s t a b l e i s o t o p e s now p e r m i t s v e r y a c c u r a t e q u a n t i t a t i v e w o r k . O n l y t h e c u r r e n t c o s t o f t h e equipment p r e v e n t s t h i s i n s t r u m e n t a t i o n from becoming the t o x i c o l o g i s t s prime t o o l . H i g h p r e s s u r e l i q u i d chromatography i s a l s o d e s t i n e d f o r a l o n g f u t u r e i n toxicology. The a b i l i t y t o s e p a r a t e p o l a r m e t a b o l i t e s i s an o u t s t a n d i n g p r o b l e m t h a t c o u l d be o v e r c o m e b y t h i s t e c h n i q u e . I t t o o may s o o n be m a r r i e d t o t h e mass s p e c t r o m e t e r . The need and tendency, t h e n , i s away f r o m c r u d e macro methods t o w a r d s s e m i - a u t o m a t e d r a p i d and s e n s i t i v e i n s t r u m e n t a l p r o c e d u r e s , w i t h an e m p h a s i s on s p e c i f i c i t y . The i n t e r p r e t a t i o n o f t h e d a t a i n r e l a t i o n t o c a s e c i r c u m s t a n c e i s a p e r e n n i a l p r o b l e m r e q u i r i n g much f u r t h e r w o r k . E f f o r t s a r e u n d e r w a y , and m u s t c o n t i n u e , t o c o m p i l e r e l i a b l e r e f e r e n c e d a t a o n p l a s m a and t i s s u e c o n c e n t r a t i o n s o f d r u g s f o l l o w i n g t h e r a p e u t i c dosage; s i m i l a r l y i n post-mortem c a s e s . The a b i l i t y t o a n a l y z e t h i s d a t a so t h a t i t s e s s e n c e c a n b e u s e d t o p r e d i c t o r e v a l u a t e f u t u r e c a s e s has b a r e l y b e g u n t o 1


17.

FiNKLE

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grow and t h i s remains a major task o f tomorrow. Meanwhile, the f o r e n s i c t o x i c o l o g i s t has come f a r i n our fast-moving s o c i e t y from the days o f hemlock and a r s e n i c to p e s t i c i d e s and n a r c o t i c s . There i s much work to be done, but w i t h good s c i e n c e and a sense of personal involvement much w i l l be accomplished. This l i g h t , broad-brush p i c t u r e o f the f o r e n s i c t o x i c o l o g i s t a t work i s a glimpse a t best,but perhaps the c u r t a i n has been r a i s e d and the i n t e r e s t of h i s f e l l o w s c i e n t i s t s stimulated to i n q u i r e f u r t h e r i n t o the a n a l y t i c a r t s . Literature 1.

2. 3.

Cited

Jackson, J.V., The Pharmaceutical P r e s s , (1969) Ed. E.G.C. Clarke, E x t r a c t i o n Methods in Toxicology in I s o l a t i o n and I d e n t i f i c a t i o n of Drugs. Sunshine, I . , Manual o f A n a l y t i c a l Toxicology, Chemical Rubber Company, (1971). F i n k l e , B.S., A n a l . Chem. S p e c i a l Report 44(9), (1972) Forensic Toxicology of Drug Abuse.


Forensic Science - ACS Publications

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