<title>Formation of methyl benzoate from cocaine hydrochloride under different temperatures and humidities</title>

Abstract

It is of interest for drug enforcement agencies to know the fate of cocaine hydrochloride when in storage. Reported here are results obtained on vapor samples collected from cocaine hydrochloride stored under several combinations of temperature and humidity. The storage conditions were varied from ambient temperature to 40 degrees C and from zero humidification to 80 percent relative humidity. Cocaine hydrochloride samples were coated onto glass beads and loaded into a glass reactor which was in turn placed inside a heated metal chamber. Ultra-zero air, conditioned to the desired humidification, was purged into the glass container, through the glass frit, over the coated beads, and the exit gas was collected onto a sorbent tube packed with Tenax TA. Any chemical product arising from the interaction between cocaine hydrochloride and the flowing air was effectively collected onto the sorbent tube, which was analyzed using a split column GC/MS technique. The results of these storage experiments showed that methyl benzoate is a predominant volatile product, even at zero percent humidification. The average formation of methyl benzoate was found to range from 1.89 ng/min with ambient/dry conditions after one hour to 62 ng.min at 40 degrees C/80 percent RH upon introduction of flowing air. These results indicate that cocaine hydrochloride exposed to any realistic humidity level in the environment will produce methyl benzoate, a volatile organic material which can be much more readily detected than cocaine hydrochloride itself.