Quantification of benzodiazepines in whole blood and serum.

A high-performance liquid chromatography method for the determination of benzodiazepines and their metabolites in whole blood and serum using mass spectrometry (MS) and photodiode array (PDA) detection is presented. The combination of both detection types can complement each other and provides extensive case relevant data. The limits of quantification (LOQ) with the MS detection lie between 2 and 3 microg/l for the following benzodiazepines or metabolites: 7-amino-flunitrazepam, alprazolam, desalkyl-flurazepam, desmethyl-flunitrazepam, diazepam, flunitrazepam, flurazepam, alpha-hydroxy-midazolam, lorazepam, midazolam, nitrazepam, nordazepam and oxazepam, respectively 5 microg/l for lormetazepam and 6 microg/l for bromazepam. The LOQ of clobazam determined with the PDA detector is 10 microg/l. A convenient approach for determining the measurement uncertainty of the presented method--applicable also for other methods in an accreditation process--is presented. At low concentrations (<10 microg/l), measurement uncertainty was estimated to be about 50%, and at concentrations >180 microg/l, it was estimated to be about 15%. One hundred and twenty-eight case data acquired over 1 year are summarised.

Isolation of Delta9-THCA-A from hemp and analytical aspects concerning the determination of Delta9-THC in cannabis products.

A simple procedure based on a common silica gel column chromatography for the isolation of Delta9-tetrahydrocannabinolic acid A (Delta9-THCA-A) from hemp in a multi-milligram scale is presented. Further, the decarboxylation reaction of Delta9-THCA-A to the toxicologically active Delta9-tetrahydrocannabinol (Delta9-THC) at different analytical and under-smoking conditions is investigated. Maximal conversion in an optimised analytical equipment yields about 70% Delta9-THC. In the simulation of the smoking process, only about 30 % of the spiked substance could be recovered as Delta9-THC.