Detection and quantification of psychotropic drug etaqualone in human hair using GC-MS/MS.

In this study, sensitive analytical procedure for detection and quantification of etaqualone in human hair samples using gas chromatography tandem mass spectrometry (GC-MS/MS) was newly established, and applied it to authentic human samples obtained from an abuser. In this method, the hair samples were treated with hydrochloric acid and then extracted with ethyl ether. The ether layer was dried in a warm water bath, and the residue was reconstituted in ethyl acetate, followed by GC-MS/MS analysis. Multiple reaction monitoring (MRM) mode was used for data collection, and quantitative analysis was performed using internal standard method. Good linear relationship within the concentration range of 1-100 pg/mg were obtained in calibrators for the hair samples showing its correlation coefficient value was 0.9993. The lower limit of quantitation in this study was 1 pg/mg and the recovery rate examined ranged from 100.4% to 108.5%. The intra-day precision and accuracy were less than 5.0% and 5.8%, respectively. The inter-day precision and accuracy were lower than 6.4% and 4.6%, respectively. Using this established method, etaqualone could be detected in the hair sample obtained from a suspected user to be level of 65.2 pg/mg. It should be expected that the method established in this study would contribute to rapid detection and identification of psychotropic drug etaqualone among multiple fields including forensic investigation, clinical application and of course public health matters.

Supramolecular solvent (SUPRASs) extraction method for detecting benzodiazepines and zolpidem in human urine and blood using gas chromatography tandem mass spectrometry.

OBJECTIVE: A high-throughput and sensitive method using supramolecular solvent (SUPRASs) for detecting 9 benzodiazepines and zolpidem in human urine and blood by gas chromatography-tandem mass spectrometry (GC-MS/MS) was newly established and applied to authentic human urine and blood samples in this study. METHODS: Urine and blood samples were subjected to liquid-liquid extractions with supramolecular solvent mixture which consists of tetrahydrofuran and 1-hexanol. The solvent layer was evaporated to dryness by stream of nitrogen. The residue was reconstituted with methanol, and subjected to analysis by GC-MS/MS in multiple reaction monitoring (MRM) mode; internal standard method was employed for quantifying of each targeted compound. RESULTS: The regression equation has a good linear relationship with correlation coefficients for all tested compounds were not lower than 0.9991. The lower limits of the quantification ranged from 0.20 to 5 ng/mL for tested compounds in urine; Meanwhile, the lower limits of the quantification in this method ranged from 1 to 50 ng/mL for tested compounds in blood. These results showed that excellent reproducibility and satisfactory extraction recovery rates could be obtained for the established analytical method for 10 drugs in both blood and urine samples. CONCLUSION: The established method in this study was high-throughput, simple and sufficiently sensitive for determining of benzodiazepinesand zolpidem in human urine and blood. Therefore, this newly established method could be of use for qualitative and quantitative determination of such drugs in urine and blood samples either for clinical poisoning monitoring or for forensic identification.