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T.A.-Gounh. and P.B. Baker.
“Identification of Major Drugs of Abuse Using Chromatography:-An Update”.
Journal of Chromotograhpic Science. 1983 April;21.
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Abstract
A review of the application of chromatography to the analysis of drugs of abuse was recently published (1), covering the period up to 1980. The present review is intended to update the previous one and therefore covers only the most recent papers. The objectives are the same, and the review is presented in a similar format. There have beers several recent papers on the separation of a wide range of drugs. Following their earlier work (2)., Dutt and Poh (3) published an identification. scheme based on thinlayer chromatography (TLC) and the colours of the ninhydrin-drug complexes formed on heating. The drug and ninhydrin were both applied to each of two TLC plates. One plate was then heated to 100 degrees C and the other to 160 degrees C. The plates were developed with' chloroform, 95 0.000000e+00thanol (5/1). The characteristic patterns and colours arising from each of the drugs were used as a basis for preliminary identification, although screening by held tests may be preferable as the first stage. Out of 49 compounds that gave colours, no two were the same. Osselton et al. (4) published further information on various stationary phases used in gas-liquid chromatography, (GLC) to separate 40 drugs. The phase SP-2250, which is a methyl-phenyl/dimethyl silicone resembling OV-17, gave the highest discriminatory power. The dimethyl silicone phase SE-30 was also suitable for routine screening. Although many drugs had rather long retention times on OV-275, this phase was able to separate structurally similar compounds that were unresolved on the other phases. This was the only stationary phase to separate cocaine from methaqualone. No mention was made of problems such as adsorption, and it should not be assumed that these phases are necessarily suitable for quantitative measurements of all the drugs studied. The same group published a compilation of retention data on SE-30 and OV-I (5). Pichari and Jacob (6) studied the retentive behaviour of some basic drugs using ion-pair high performance liquid chromatography (HPLC) with a system similar to that described. Lurie (7,8) and previously reviewed. Lurie and Oemchuk also studied the optimisation of a reversed phasc ion-pair system for various drugs of forensic interest (9,10). About 50 drugs were exatmined, and the effect of column packing, eluant composition, alkyl chain length, and concentration of the counter-ion on spearation was studied. After separation by HPLC, King (11) used fluorescent and ultraviolet (UV) detectors in series. Over 70 drugs were examined, although they were not all resolved from each other, particularly the acidic drugs. About half of the drugs showed no fluorescence, notably amphetamine, cocaine, heroin, lignocaine, methadone, and pethidine, but the method was nertheless useful for screening purposes.
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