Analysis of phenylpiperazine-like stimulants in human hair as trimethylsilyl derivatives by gas chromatography–mass spectrometry

Determination of ketamine and its major metabolite, norketamine, in urine and plasma samples using microextraction by packed sorbent and gas chromatography-tandem mass spectrometry

“…Six weighting factors were evaluated for each analyte (1/ √ x, 1/x, 1/x2, 1/ √ y, 1/y, 1/y2), and the one which originated the best results was selected taking into account the data obtained during the assessment of the inter-day precision and accuracy [50]. This choice was performed by calculating the mean RE for each weighting factor and summing the absolute values.…”

“…The accuracy of the method was characterized in terms of the mean RE between the measured and the spiked concentrations; the accepted limit was 15% for all concentrations, except at the LLOQ, where 20% was accepted. For recovery studies, blank samples were spiked with both analytes at three concentrations for urine (50, 100 and 200 ng/mL) and four concentrations for plasma (50,100,200 and 500 ng/mL) and analyzed by the described method (n = 3), after which the IS was added. At the same time, blank extracts were spiked with the same quantity of the analytes and IS after elution.…”

Detection of New Psychoactive Substances

“…These compounds can be structurally divided in two subgroups (benzylpiperazine and phenylpiperazine) [43]. These compounds can be structurally divided in two subgroups (benzylpiperazine and phenylpiperazine) [43].…”

Development and validation of a gas chromatography/mass spectrometry method for simultaneous quantification of benzylpiperazine and its metabolites: Application to a pilot toxicokinetic study in mice

“…With regard to BZP, the analytical methods published are normally only used to detect and/or quantify BZP in combination to its main metabolites (14,15,96) or few other piperazines also used as designer drugs (89, 94,95,99). Nevertheless, some other methods also allow the identification of BZP in combination with other stimulant drugs being very useful in the rapid screening of biological samples with a forensic and for clinical purpose (16,97,98,(100)(101)(102).…”