RESUMO
We report determination of metabolites of popular drugs of abuse, including nimetazepam and nitrazepam, in urine by using liquid chromatography/mass spectrometry. Nimetazepam and its metabolites, 7-aminonimetazepam and nitrazepam, were extracted by solid-phase extraction using a DAU cartridge. An ammonium acetate buffer solution (pH 4) and a Luna polar-RP column were selected as the mobile and stationary phase, respectively, for liquid chromatography. Mass spectrometry was used for analysis and was optimized for operation in the positive mode for all analytes. The urine specimens were screened for the presence of nimetazepam and its metabolites nitrazepam and 7-aminonimetazepam at a concentration of 0.1ng/mL. Presence of 7-aminonimetazepam in the urine was an indicator of the subject being a probable abuser of nimetazepam.
Assuntos
Hipnóticos e Sedativos/urina , Nitrazepam/análogos & derivados , Cromatografia Líquida , Toxicologia Forense , Humanos , Hipnóticos e Sedativos/química , Estrutura Molecular , Nitrazepam/química , Nitrazepam/urina , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Espectrometria de Massas em TandemRESUMO
We report the simultaneous screening of highly polar, water-soluble, and less-volatile herbicides, including glyphosate, glufosinate, paraquat, and diquat, in serum using liquid chromatography-mass spectrometry. The herbicides were separated by solid-phase extraction using a Strata-XC cartridge. A heptafluorobutyric acid solution was chosen as the mobile phase for ion-pair liquid chromatography. Mass spectrometry was used for analysis and was optimized for operation in the positive mode for all analytes. The serum specimens were screened for the presence of the herbicides at the following concentrations: 5 ng/mL for glyphosate, 2 ng/mL for glufosinate, 1 ng/mL for diquat, and 5 ng/mL for paraquat. This is the first report on the simultaneous detection of these compounds.
Assuntos
Cromatografia Líquida/métodos , Herbicidas/sangue , Espectrometria de Massas em Tandem/métodos , Fluorocarbonos/química , Herbicidas/química , Humanos , Reprodutibilidade dos Testes , Extração em Fase Sólida/métodos , Água/químicaRESUMO
When underivatized methamphetamine hydrochloride (MA.HCl) in methanol is subjected to the instant gas chromatographic-mass spectrometric (GC-MS) profiling with old inlet liners at temperatures above 200 degrees C, appreciable amounts of N,N-dimethylamphetamine (DMA) and amphetamine (AP) are produced. The presence of these two artifacts is attributed to the N-demethylation and N-methylation reactions of MA as well as methyl group exchange with methanol. These artifacts are only produced in old injection port liners and at elevated temperatures. The formation of artifacts is proportional to concentration of MA.HCl. It is suggested that special cautions and measures be undertaken to prevent artifacts.