Source identification of Indian opium based on chromatographic fingerprinting of amino acids.

Total and free pool of amino acids was determined in Indian opium samples using liquid chromatography (LC) with post-column opthalaldehyde derivatization followed by its fluorimetric detection. The limit of detection (LOD) was found to be in the range of 2-10 pmol with a signal to noise ratio of 3:1 and limit of quantitation (LOQ) was found to be in the range of 7-31 pmol with a signal to noise ratio of 10:1. The recovery of amino acids was found to be in the range of 86-103%. A total of 124 Indian opium samples were collected from the states of Madhya Pradesh (MP), Uttar Pradesh (UP) and Rajasthan (Raj), covering 14 licit opium growing divisions of India were chromatographically fingerprinted for the presence of various amino acids. The amino acids identified in sample hydrosylate included D, T, S, S, G, A, V, I, L, Y, F, H, K and R, while the analysis of free pool of amino acids (80% aqueous ethanol extract) indicated the presence of D, T, S, E, A, V, I, L, Y, H, K respectively. Multiple discriminant analysis was applied to the quantitative total amino acid data to determine an optimal classifier in order to evaluate the source of Indian opium. The foremost amino acid variables that accounted for the true discrimination were identified as D, E, G, A, F and K in evaluating the geographical origin of Indian opium and the predictive value based on the discriminant analysis was found to be 90% in relation to the source of opium samples. Chemometrics performed with amino acid analytical data was used successfully in discriminating the licit opium growing divisions of India into three major groups, viz. groups I, II and III. The methodology developed may find wide application in forensic analysis.

Quantitative evaluation of 28 mineral elements by inductively coupled plasma/mass spectrometry and its application in source identification of Indian opium.

An analytical method based on inductively coupled plasma/mass spectrometry (ICP/MS) was developed for the determination of 28 mineral elements (Cr, Mn, Co, Ni, Cu, Zn, Ga, Sr, Cd, Ag, Ba, Pb, Bi Y, La, Ce, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) in Indian opium samples. The detection limits were found to be in the range of 0.0008-0.45 ng/mL. The recoveries of spiked samples for each element were found to be in the range of 83-106%, with a precision of less than 9%. A total of 124 opium samples from India were analyzed for the distribution pattern of the 28 mineral elements. Quantitative elemental data were subjected to chemometric analysis in order to determine an optimal classifier to evaluate the source of Indian opium. The study indicated that mineral elements might not be the suitable discriminators for the discrimination of licit opium-growing divisions of India. However, the methodology developed and the analytical data on elemental profile may find important forensic application in discriminating Indian opium with that of licit and illicit opium originating from different geographical regions of world.

Determination of diazepam in cream biscuits by liquid chromatography.

An analytical procedure was developed for the detection and quantitation of diazepam in cream biscuits, which were used to commit crime. The method involves the extraction of diazepam with ethanol at room temperature, and the extract is filtered, evaporated to dryness, and redissolved in the mobile phase, methanol-acetonitrile-tetrahydrofuran-water (15 + 55 + 4 + 26, v/v). The separation is achieved on a C18 reversed-phase column with the mobile phase and diode array detection (lambda(max)) at 230 nm. Medazepam is used as the internal standard is for quantification. The calibration plot for the determination of diazepam is based on linear regression analysis (y = 0.6687x + 0.0372; r2 = 0.995). The limit of detection for diazepam in the biscuit samples was estimated as 600 ng/mL. The limit of quantitation for diazepam was estimated as 1.75 microg/mL. The diazepam detected per piece of biscuit was found to be in the range of 0.27-0.45 mg. Pure diazepam was added to biscuit samples at 3 levels (100 and 500 microg/g, and 1 mg/g), and the recoveries were found to be 95%. The mean retention time of diazepam was 2.7 min and that of medazepam (IS) was 4 min. The relative standard deviations of the diazepam level in the biscuit samples were estimated to be 0.4% for retention time and 1.02% for peak area in intraday analysis, whereas the corresponding values were and 0.61 and 2.34% in interday analysis. The method is rapid and reliable for qualitative and quantitative analysis of cream biscuits laced with diazepam, and it can be used by law enforcement laboratories for routine analysis.