Gough TA, Baker PB.
“Identification of Major Drugs of Abuse Using Chromatography”.
Journal of Chromatographic Science. 1982 July,;20, No. 7.
This paper reviews the use of chromatography for the separation and subsequent identification of drugs that are commonly abused in Western society. Analytical data on drugs of abuse are of value in various fields, notably law enforcement, toxicology, pharmacy, pharmacology, and chemobotany. However, the analytical approach will of necessity depend upon which of these fields is involved. In law enforcement there is usually no shortage of the drug, and one problem facing the analyst is that of obtaining representative samples from perhaps several kilograms of material. In contrast, the toxicologist may be required to detect nanogram quantities in blood or urine. It is the intetion of the reviewers to consider the role of chromatography in relation only to the analysis of the raw or prepared materials, and not to their detection after administration to animals or humans. The reviewers do not claim to cover all papers falling within this category, but have deliberately selected for discussion papers typical of a particular procedure. There have been major advances in instrumentation over the last few years, particularly in liquid chromatography, and this has had major impact on drug analysis. The reviewers recognise, and indeed emphasise, that there are many instances where a simple and cheap technique is adequate, and it is not always necessary to resort to sophisticated instrumentation. This review covers all aspects of chromatography from thin layer systems to combined gas chromatography and mass spectrometry (although mass spectrra are not discussed), and covers the main publications over the past decade. There are references to earlier papers, particularly on thin layer chromatography (TLC), but only where the work is of special interest or where no significant advnaces have since been made. There is, inthe reviewer's opinion, no "best method" of analyiss; methods other than chromatography are indeed valualbe in many cases. It is, however, uncommon to rely solely on no-separatory techniques simply because drugs are usually encountered as mixtures, either with other related mateials, cutting agents, or excipientes. In conjunction with chromatography, ultra-violet (UV) and infra-red (IR) spectroscopy (as appropriate) are used for screening or confirmation. Mass spectrometry (MS) is also used for confirmation, often on-line with gas/liquid chromatography (GLC), and MS reference data are available (1,2). The methods of choice will depend on the particular problem at hand, the use to which the data will be put, and the time and facilities available. It is hoped that this review will enable the analyst to select the chromatographic method most approprieate to the situation. In the past few years there have been a number of papers in which a particular chromatographic technique has been used for the separation of a wide range of drugs of abuse. Apart from a short list of very commonly encountered drugs, including heroin, cannabis, an dcocaine, many drugs are seen only occasionally and some are almost never encountered even at "street level." A breakdown of illicit importations into the United Kingdom (UK) of drugs controlled by the Misuse of Drugs Act (1971) showed that in 1979, 800f all cases examined by this Laboratory on behalf of the customs authorities related to cannabis products. Heroin and other narcotics represented 16%, cocaine 3%, and all other controlled drugs made up the remaining 1%. Over the same period, the proportions seized within London and Southeast England by the civil police were 66 0.000000or cannabis products, 9 0.000000or narcotics, 2 0.000000or cocaine, and 23 0.000000or all other drugs (whether or not controlled by the Misuse of Drugs Act). In the United States of America (USA), the proportions of seizures, estimated from numbers of arrests during 1979 reported by the Drug enforcement Administration, were cannabis 24%, narcotics 20%, cocaine 32%, and other drugs 24%.