A High Performance Liquid Chromatography-tandem Mass Spectrometry Method For The Determination Of Five Sedatives Residues In Aquatic Products

Some people take the methaqualone, diazepam and its metabolites in aquatic products, keeping them alive or fresh for a long time at all points, while these drugs may pose a threat to human health. Bulletin No. 235 issued by Department of Agriculture has defined that"methaqualone used in animal is banned and not be detected in food of animal origin ," " diazepam is allowed for cure and not be detected in food of animal origin." Until now, most of methods home and abroad are suitable for the determination of methaqualone,diazepam and its metabolites in human plasma ,human urine, farming feed , pork and beef , not for aquatic products with complex matrix. We describe structure of methaqualone, diazepam and its metabolites first, pharmacological actions, metabolism, hazards; analyze and summarize achievement home and abroad and compare in the chart; take research based on previous experience. After Optimizing the conditions of liquid chromatography - tandem mass spectrometry and methods of sample pretreatment, we draft industry standard "A high performance liquid chromatography - tandem mass spectrometry method for the determination of methaqualone in aquatic products "; established a method " a high performance liquid chromatography - tandem mass spectrometry method for the determination of diazepam in aquatic products and its metabolites ".An industry standard, "A high performance liquid chromatography - tandem mass spectrometry method for the determination of methaqualone in aquatic products": The sample was extracted twice by hexane. The extracts were concentrated and then cleaned up by silica solid phase extraction cartridge, concentrated to dryness, redissolved in methanol– water (5:5, by volume). The separation of analytes was performed on a CAPCELL PAK MGⅡC18(100mm*2.1mm id,3.5μm) column by gradient elution with methanol (A) - 0.1% formic acid (B) as the mobile phases. The analytes were carried out by electro– spray ionization (ESI) in positive mode under selective reaction monitoring (SRM) mode, An internal standard method was used for quantitative analysis of targeted compounds. The calibration curves were good linear in the range of 5～250 ng/mL with correlation coefficients more than 0.9990. The limits of quantification of methaqualone in aquatic products were 1μg/kg. The average recoveries from spiked aquatic products tissues at three concentration levels of 1, 10 and 50μg/kg ranged higher than 70% with RSD lower than 15%. In addition, we do study on stability .The method was effective and sensitive, and was suitable for the determination and confirmation of methaqualone in aquatic products. We select representative fish with high value in the Shanghai market, eel, sea bass, Mandarin fish, process by the method we have established, methaqualone not detected.A high performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS) method was developed for determination of diazepam and its metabolites in aquatic products. The sample was extracted twice by ammonia - acetonitrile (1%, by volume). The extracts were concentrated, defatted with hexane and then cleaned up by HLB solid phase extraction cartridge, evaporated to dryness, redissolved in methanol– water (5:5, by volume). The separation of analytes was performed on a CAPCELL PAK MGⅡC18(100mm*2.1mm id,3.5μm) column by gradient elution with methanol (A) - 0.1% formic acid (B) as the mobile phases. The analytes were carried out by electro– spray ionization (ESI) in positive mode under selective reaction monitoring (SRM) mode, An internal standard method was used for quantitative analysis of targeted compounds. The calibration curves were good linear in the range of 5～250 ng/mL with correlation coefficients more than 0.990. The limits of quantification of diazepam and its metabolites in aquatic products were 1μg/kg. The average recoveries from spiked aquatic products tissues at three concentration levels of 1, 10 and 50μg/kg ranged from 81.7%～119.8% with RSD of 1.7%～14.2%. The method was effective and sensitive, and was suitable for the determination and confirmation of diazepam and its metabolites in aquatic products. We select representative fish with high value in the Shanghai market, eel, sea bass, Mandarin fish, and process by the method we have established, diazepam and its metabolites not detected.At present, people are concerned for food safety more and more, risk assessment has become a hot topic in the industry. The two achievements of our study will provide technical support in future!...