|
The volatile organic compounds in seized cocaine hydrochloride were analyzed using Gas Chromatography Mass Spectrometry (GC/MS). Two different methods of sampling volatile compounds were investigated. In the first method, 20, 50, and 100 mg samples of seized cocaine hydrochloride were loaded into 2-inch glass tubes. The headspace of each tube was then purged with ultra high purity (UHP) helium and the gas exiting the tube was directed through a cryogenic loop filled with glass beads and maintained at liquid nitrogen temperature. The volatile organic compounds were collected onto the glass beads while the helium gas was vented. The organic compounds were subsequently thermally desorbed onto the column and analyzed by GC/MS. In the second method, 10 mg and 100 mg samples of seized cocaine hydrochloride were loaded into glass tubes fitted with glass frits at one end. UHP helium was purged through each sample and the purge gas containing organic compounds was collected onto a sorbent tube packed with Tenax TA. The concentrated organic compounds were then thermally desorbed onto a 4 m section of a split GC capillary column maintained at -70 degrees C with flow rates of 20-28 ml/min. Flow was returned to 2.8 ml/min during analysis. By sampling the seized samples of cocaine hydrochloride using a cryogenic loop, methanol, methyl ethyl ketone, acetic acid, 2,2,4-trimethyl pentane, 2-methyl pentane, dichloromethane, 2-propanol, and 2-propanol, and 2-propane (acetone) were found in three different seized cocaine hydrochloride samples. The observed quantities of these volatile organic compounds were different for each of the three seized cocaine hydrochloride samples. THe observed quantities of these volatile organic compounds were different for each of the three seized samples labeled A, B, and C. By sampling the seized samples of cocaine hydrochloride using sorbent tubes, cocaine was consistently observed. Although volatile components other than cocaine were observed, the number and amount of volatile components were not consistent with the cryogenic loop results.
|
