Detection of Cocaine in Seized Drug Samples by Capillary Electrophoresis Tandem Mass Spectrometry
A methodology using capillary electrophoresis with tandem mass spectrometry detection (CE-MS/MS) was developed, and applied to determine the cocaine content of seized drugs. The cocaine separation among other concomitants by capillary electrophoresis was achieved in just 4.0 minutes using 30 mM ammonium formate, pH 6.5, as a background electrolyte (BGE). The correlation coefficient of the calibration curve in the range of 0.02 to 1 μg/mL was upper 0.999, and the limits of detection (LOD) and limits of quantification (LOQ) were 0.003 μg/mL and 0.01 μg/mL, respectively. The relative standard deviation repeatability (intraday and interday) was less than 6.5% (peak area). The analysis of seized suspected illegal drugs revealed the presence of cocaine in 93% of samples (n = 11), in amounts ranging from 0.04 to 429 mg/g, showing a high variability of concentrations of cocaine. The user can change the provider and, due to the large variability of concentration, be lead to an accidental overdose.
Further studies on spot tests and microcrystal tests for identification of cocaine.
The presence of cocaine in illicit drug samples is still being determined in some laboratories using spot tests and microcrystal tests. Seventeen chemical species were tested using three different spot tests (Wagner, Marquis, and cobalt thiocyanate followed by stannous chloride reactions) and two microcrystal tests (gold chloride and platinic chloride) to determine whether the results could be differentiated from the results of these tests on cocaine. The data obtained indicated that nine of the 17 compounds gave results similar to those from cocaine using the three spot tests, but that the results from microcrystal testing allowed for differentiation of all nine compounds from cocaine.
MICROCHEMICAL TESTS FOR THE IDENTIFICATION OF ALKALOIDS
OF the methods available for the identification of minute quantities of alkaloids, the production of microcrystalline derivatives of characteristic form and habit is generally acknowledged to be the most delicate and the most reliable. Colour reactions, while sometimes of great value as confirmatory tests, are not of universal application and suffer from the defect that small traces of impurity may give rise to misleading results. Physiological tests, using living animals, are, on the whole, less sensitive than chemical tests and can only be carried out by persons holding a Home Office licence. Paper chromatography’ thohgh promising, is as yet largely untried. Microcrystalline tests have been developed by many workers including Wormley2, Stephenson3, Fulton415, WhiteE, Wagenaar’, and OliverioE, but this development has consisted in the introduction of new reagents rather than in the elaboration of the technique itself. Tests have usually been carried out by placing a drop of the test solution on a microscope slide, adding a drop of the reagent, and examining under low magnification. As this method does not give satisfactory results when dealing with quantities of less than 1 mg., the technique described below has been introduced for the identification of alkaloids when only a few pg. are available.