ABSTRACT
Objective To establish a method using supramolecular solvent and gas chromatography-tandem mass spectrometry （GC-MS/MS） to analyze 9 benzodiazepines in urines. Methods Urine samples containing 9 benzodiazepines reference substance were subjected to liquid-liquid extractions with supramolecular solvent, which consisted of tetrahydrofuran and 1-hexanol. The solvent layer was evaporated to dryness by stream of nitrogen. The residue was reconstituted with methanol, and GC-MS/MS analysis was performed on it. The way of data collection was multiple reaction monitoring （MRM） mode; internal standard method was employed for quantification. Results In urine samples, when the range of mass concentration was 1-100 ng/mL for diazepam, midazolam, flunitrazepam and clozapine, 5-100 ng/mL for lorazepam and alprazolam, 2-100 ng/mL for nitrazepam and clonazepam, and 0.2-100 ng/mL for estazolam, respectively, good linearities were obtained, correlation coefficients were 0.999 1-0.999 9, the lower limits of the quantifications ranged from 0.2 to 5 ng/mL, the extraction recovery rates were 81.12%-99.52%. The intra-day precision ［relative standard deviation （RSD）］ and accuracy （bias） were lower than 9.86% and 9.51%, respectively; the inter-day precision （RSD） and accuracy （bias） were lower than 8.74% and 9.98%, respectively. Nine drugs in urine samples showed good stability at ambient temperature and -20 ℃ within 15 days. The mass concentrations of alprazolam in urine samples obtained from 8 volunteers who took alprazolam tablets orally within 8-72 h after ingestions ranged from 6.54 to 88.28 ng/mL. Conclusion The supramolecular solvent extraction GC-MS/MS method for analysis of 9 benzodiazepines in urines provided by this study is simple, fast, accurate and sensitive, which can provide technical support for monitoring of poisoning by benzodiazepines for clinical treatment and judicial identification.
Subject(s)
Humans , Benzodiazepines , Chromatography, Liquid , Gas Chromatography-Mass Spectrometry , Solvents , Tandem Mass SpectrometryABSTRACT
A new method for the rapid determination of total phthalates (PAEs) in edible oils was developed. The PAEs in edible oils all were hydrolyzed to phthalic acid with tetrabutylammonium chloride (TBAC) as catalyst. Then phthalic acid was extracted by the supramolecular solvent ( SUPRAS) made up of octanol, tetrahydrofuran and aqueous solution, and detected by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS / MS). As a result, hydrolysis time was 10 min. The linear range of phthalic acid was 0. 05- 2. 0 mg / L with a good correlation coefficients ( r > 0. 999). The limits of detection ( LOD) and quantification (LOQ) were 5. 41 and 18. 05 μg / kg, respectively. The recoveries of target analyte at three spiked levels were in the range of 84. 6% - 104. 5% . The repeatability, expressed as relative standard deviation (RSD), was 2. 6% for intra-day and 3. 7% for inter-day. The total PAEs content of 12 edible oils was found in the range of 0. 30-1. 09 mg / kg.