Poly(vinyl chloride) matrix membrane electrode for the selective determination of heroin (diamorphine) in illicit powders

Abstract

The potentiometric response characteristics of a poly(vinyl chloride) membrane electrode for heroin based on its ion-pair complex with tetraphenylborate were examined. The influence of pH, temperature and time on the performance of the electrode system was investigated. The electrode shows a near-Nernstian response over the heroin concentration range 10(-2)-10(-4) M with good precision. The mean relative standard deviation for the determination of heroin in 40 micrograms ml-1(-1) mg ml-1 aqueous heroin hydrochloride solutions is 1.2%. The electrode exhibits good selectivity for heroin in the presence of a number of adulterants and basic organic compounds commonly present in illicit heroin powders. The method was applied to the direct potentiometric determination of heroin in illicit powders (10-36% heroin) and the results agreed fairly well with those obtained by gas - liquid chromatography.

Characterization of Some “Hashish” Samples in the Egyptian Illicit Trafficking Market Using a Thermal Separation Probe and Gas Chromatography–Mass Spectrometry

“…13 Characterization and analysis of natural and artificial illegal narcotics have been the subjects of detailed studies in our laboratories during the last two decades. Methods for the determination of heroin, 18 cocaine, 19 morphinen, 20 ethylmorphine, 21 amphetamine, 22 and harmine and harmaline 23,24 have been previously described. However, little is known about the composition and concentrations of the active and inactive ingredients of the most common form of drug abuse, "hashish", in Egypt.…”