Evidence of mephedrone chronic abuse through hair analysis using GC/MS

Abstract

Mephedrone is a synthetic derivative of cathinone which is becoming more common on the recreational drug market. Several intoxications following mephedrone abuse have been reported though published papers have focused essentially on analytical approaches for biological fluids and only one has involved a hair sample. After the development and validation of a new method, the first series of positive results for mephedrone in hair specimens is reported here. After decontamination of the hair strand in methylene chloride, hair segments were cut into small pieces with scissors, weighed and incubated overnight in Soerensen buffer pH 7.0 in the presence of deuterated 3,4-methylenedioxymethamphetamine (MDMA) at 40°C. The incubation medium was extracted using ethyl acetate after alkalinisation with 1N sodium hydroxide (NaOH). Before injection, the dry extract was derivatized using a mixture of heptafluorobutyric anhydride/ethyl acetate (100:50, v/v), evaporated and dissolved in ethyl acetate (25μl). After introduction of 1μl of the extract onto a splitless injector, chromatographic separation was achieved on a HP 6890 gas chromatograph equipped with a 5-MS capillary column. Detection was achieved in single ion monitoring mode (m/z 254-119-210 for mephedrone, m/z 258-213 for MDMA-d5) using a 5973 MSD operating in electron impact mode. Sixty-seven hair specimens were tested for mephedrone. Thirteen of them were found positive for mephedrone with concentrations ranging from 0.2 to 313.2ng/mg with a mean concentration of 26.8ng/mg. It was difficult to compare our findings due to a lack of reference data, nevertheless mephedrone seems well incorporated into hair (concentrations in the ng/mg range) like other stimulant drugs such as amphetamines or cocaine. The aim of this work was to develop a specific and accurate method for mephedrone analysis in hair specimens and its application to a large number of samples (n=67). The developed analytical method appears sensitive enough to reveal occasional to regular use of mephedrone.