Henk Huizer

Heroin impurity profiling : A harmonization study for retrospective comparisons

Three laboratories present a harmonised system for the retrospective comparison of south west Asian heroin. It consists of an improved gas chromatographic (GC) profiling method and a computerised data retrieval. The investigations of the GC were necessary with a view to improve the reproducibility of the system. The necessity of a strict quality control is emphasized. The peaks of the GC profile were investigated for abundance, intensity, GC behaviour (reproducibility) and correlations; 16 of them were selected for describing the heroin profile in the database. The results from intra-lab profile comparisons are reported. The reproducibility of the analysis was good and the variation between the samples was large, thus, allowing conclusions with a high degree of certainty. The criteria of similarity were defined. The system is successfully running in all three labs. In connection with inter-laboratory comparison, the aspects of method harmonisation and standardisation are discussed. It appeared that the GC method is a very subtile one, urging for a strict standardisation between the three labs. Despite a long cooperation between three well-equipped and experienced labs, a more or less serious loss of reproducibility was noticed in the inter-lab results in comparison with the intra-lab results. The loss could for the greater part be attributed to the (limits of the) GC technique; a number of compounds, necessary for making the discrimination between samples, showed difficult chromatographic behaviour, leading to insufficient inter-lab reproducibility. Using the actual variables, improvements in performance can hardly be expected in the near future. The loss of reproducibilty implies that the number of false positive matches in a database search increases. This may strongly reduce the value of a relatively large, international database. The study shows that so far, the best option for international comparison is the analysis in a central laboratory. The idea of local determination at a large number of national labs and the use of a common database is not a realistic aim for this type of analysis.

Di-( β -Phenylisopropyl)amine in Illicit Amphetamine

Illicit amphetamine samples frequently contain di-(β-phenylisopropyl)amine as a main impurity. Its formation during the Leuckart synthesis is discussed. A method for synthesis is given. Special attention is given to its stereoisomerism. Analytical data are presented; the role of the compound in the comparison of illicit amphetamine samples is discussed.

1-phenylethylamines: a new series of illicit drugs?

Since 1993 many seizures of 1-phenylethylamine have been made in several European countries. It was originally thought that 1-phenylethylamine had been made in error, but later information suggested that it had been prepared deliberately. The related compounds, 1-amino-1-(4-methylphenyl)ethane and 1-methylamino-1-phenylethane and the 1-propanamine isomer of 3,4-methylenedioxyamphetamine, have also occurred in isolated cases. Analytical data are presented on these amines as well as a number of Leuckart impurities in 1-phenylethylamine. The pharmacological effects of these substances are largely unknown.

Quantitation of amphetamine-type compounds for which no reference compound is available: the validation of a theoretical model

Introduction An important aspect in quantitative analysis of illicit drugs is the availability and reliability of the reference compound. For compounds (still) used in pharmacy, there is usually no problem; these are generally supplied with a certificate stating their purity and are available in sufficient amount to allow verification, for example by melting point determination, titration or water determinations.