Chemical characterization and quantitative estimation of narcotic drugs in the seized illicit samples by GC-MS and GC-FTIR, identification of source and possibility of isotopic substitution

Qualitative and quantitative forensic investigation of about thirty selected street drugs samples seized in between 1998-2003 from different regions of India were made using standard procedures followed by the use of sophisticated methods like GC-MS, GC-FTIR as per forensic protocol. The analysis of samples showed the presence of heroin, codeine, acetylmorphine, acetylcodeine, papaverine, noscapine, phenobarbital, methaqualone, paracetamol, strychnine, caffeine. nitrazepam with other variants and diluents. Adulterants and diluents formed 80% of the illicit samples. Heroin percentage were found to be low in most cases. Attempts were made to gather information regarding geographical origin and the distribution network of illicit samples. Methods suggested for the identification of source were analyzed. Isotopic signature of the elements in the samples using IRMS and biomarker identification appeared to be the best methods for source determination but could not be utilized due to lack of IRMS instrument and absence of data on biomarkers. However, no isotopic substitution was observed in the samples from GC-MS experiments but idea of isotopic abundance of elements collectively was obtained. FTIR measurements, used to identify the compounds and group frequencies of the compounds in the illicit samples could be utilized to determine the ratios of C-13/C-12 of the compounds. However, determination of source or route of drug trafficking appeared to be illusive unless there are vast collection of authentic illicit drugs from different countries are available.