Determination of impurities and adulterants of cocaine in Sri Lanka by gas chromatographic mass spectrometric method to identify any correlation

Abstract

Cocaine is the second most problematic abused drug produced from the leaves of Erithroxylum Coca. In this respect, it is very important to find out the origin of the seized cocaine and the route of trafficking. The impurities present in samples gives an idea about the method of manufacture. The aim of this study was to develop a suitable Gas Chromatographic Mass Spectrometric (GC-MS) method for qualitative analysis of impurities and adulterants in samples of cocaine to identify any correlation. In this study, fifty (50) cocaine samples were collected from the Government Analyst’s Department of Sri Lanka. The analytical results revealed that all samples analyzed were cocaine hydrochloride salts. A GC-MS method involving one step derivatization procedure was developed for qualitative and quantitative analysis of impurities & adulterants in cocaine samples. Agilent model 7890 A GC coupled with Agilent 5795C inert XL MSD with Triple-Axis Detector was used in this  study with a HP 5 MS 5% phenyl methyl Silox 325C column. Derivatizing agent used in this study was N, O-bis, (trimethylsilyl) acetamide. Fifteen were identified as impurities in this study and showed well separated peaks in the chromatogram. According to the results of the impurities in   cocaine samples, eighteen (18) different profiles were identified. Further, with respect to identified impurities it was concluded that twenty-three (23) samples manufactured from the illicit synthetic procedures while the other twenty-seven (27) samples manufactured using illicit natural synthesis procedures. Further, Lidocaine, Caffeine, Levamisole, Phenacetin and Acetaminophen were identified as adulterants. Among the identified adulterants levamisole was the most abundant (65% of the total samples) Acetaminophen, Phenacetin, Caffeine, and Lidocaine were found in 30 %, 20%, 33%, and 42% of samples respectively.The same GC-MS method was applied to quantify ecgoninemethylester and benzoylecgonine in the samples and the percentages were in the range 0.2- 4% and 2-11% respectively while percentage of adulterants Acetaminophen, Caffeine, and Lidocaine and levamisole were 5- 10%, 5-8%, 4-6% and 2-3% respectively