title: [Simultaneous determination of penicillin and their major enzymatic metabolites in milk and milk powder by high performance liquid chromatography-tandem mass spectrometry].
abstract: A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/ MS) method has been developed for the determination of eight compounds in milk and milk powder. They are four penicillins (penicillin G, penicillin V, amoxicillin and ampicillin) and four major beta-lactamase enzymatic metabolites of them (penilloic acid G, penilloic acid V, amoxiilloic acid and ampilloic acid). The compounds were extracted from the samples with acetonitrile and water, cleaned-up by HLB solid-phase extraction cartridges, and then detected by HPLC-MS/MS and quantified by external standard method. The linearities were satisfactory with the correlation coefficients > 0.99 at the mass concentrations ranging from 4 microg/L to 200 microg/L for penicillins and from 10 microg/L to 500 microg/L for enzymatic metabolites. The limits of detection and the limits of quantification were 5-50 microg/kg (S/N > or = 3) and 8-100 microg/kg (S/N > or = 10), respectively. The average recoveries of the eight compounds were 83.48%-96.97% in milk and 82.70%-95.14% in milk powder. The relative standard deviations (RSDs) in milk and milk powder were 3.86%-10.87% and 3.02%-9.81%, respectively. In conclusion, the established method is convenient, accurate and sensitive so that it can be applied to the determination of penicillin residues and enzymatic metabolites in milk and milk powder.
authors.affiliation: Hebei Entry-Exit Inspection and Quarantine Bureau, Shijiazhuang 050051, China. liwei.305@163.com
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Hebei Entry-Exit Inspection and Quarantine Bureau, Shijiazhuang 050051, China.
authors.forename: Lianfeng
authors.initials: L
authors.lastname: Ai
authors.affiliation: Hebei Entry-Exit Inspection and Quarantine Bureau, Shijiazhuang 050051, China.
authors.forename: Chunhai
authors.initials: C
authors.lastname: Guo
authors.affiliation: Hebei Entry-Exit Inspection and Quarantine Bureau, Shijiazhuang 050051, China.
authors.forename: Yusong
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Hebei Entry-Exit Inspection and Quarantine Bureau, Shijiazhuang 050051, China.
authors.forename: Caiyun
authors.initials: C
authors.lastname: Dou
mesh_terms: D000658:Amoxicillin; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004350:Drug Residues / Q000032:analysis*; D005506:Food Contamination / Q000032:analysis*; D013058:Mass Spectrometry; D008892:Milk / Q000737:chemistry*; D010400:Penicillin G / Q000031:analogs & derivatives; D010406:Penicillins / Q000032:analysis*; D011208:Powders; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry
chemical_list: D010406:Penicillins; D011208:Powders; D000658:Amoxicillin; C017609:penilloic acid; D010400:Penicillin G