| The purpose of this study was to establish a method for penicillin G residue in poultry tissues(chicken muscle,chicken liver,chicken kidney,goose muscle,duck muscle),eggs and duck eggs(whole egg,albumen,yolk)and pork by gas chromatography-tandem mass spectrometry(GC-MS/MS)detection method.In this experiment,Haiyang yellow chicken,Gaoyou duck,Yangzhou goose,and Three-way cross hybrid pig(DurocxLandracex Large White)were selected as the experimental animals.Accelerated solvent extraction(ASE)and solid phase extraction(SPE)technologies were used to extract and purify the target.The GC-MS/MS detection method was developed and optimized for determination of penicillin G residue in poultry tissues,poultry eggs and pork.The main results of this research are shown as follows:1.The reaction conditions of the derivatization of penicillin G and trimethyl silyl-diazomethane(TMSD)were established and optimized,and the derivatization products were determined.That is,100 μL 1.0 pg/mL penicillin G and 400 μL TMSD were put in a 2.0 mL brown centrifuge tube,sealed and reacted at 30℃ in the oven for 30 min in the dark,and then,Penicillin G trimethylsilyl methyl ester was produced.2.A method was firstly adopted for the extraction of penicillin G in poultry tissues,poultry eggs and pork by accelerated solvent extraction(ASE),and the parameters of ASE(temperature,time,and percent rinse)were optimized,that is,poultry tissues,poultry eggs and pork were degreased with n-hexane and rinsed with 40%under 30℃ and 1500 psi conditions,then,the penicillin G residue from poultry tissues and pork were extracted with 0.2 M phosphate buffer solution(pH 8.0),and the penicillin G residue from poultry eggs were extracted with 80%acetonitrile.The static extraction time is lasted for 5 minutes and extraction 2 times.This method improves extraction efficiency and reduces sample matrix effects.This method also has good repeatability and saves reagents,and also is fully automatic3.A GC-MS/MS method was established and optimized for the first time,to determine penicillin G residue in poultry tissues,chicken eggs,and duck eggs(whole egg,albumen,and yolk)and pork.Electron ionization was adopted,with Full SCAN and Auto SRM was used for qualitative or quantitative purpose.The results are shown as follows:within the dosing level of the limit of quantitation(LOQ)～200.0 μg/kg for penicillin G in blank poultry(chicken muscle,goose muscle,duck muscle),pork and poultry eggs(egg,duck egg),the peak area of quantificational ion of the derivatized product,m/z 174.1>114.1*,showed a good linear correlation with concentration(R2>0.9994);within the dosing level of the limit of quantitation(LOQ)～250.0μg/kg for penicillin G in blank chicken liver and chicken kidney,the peak area of quantificational ion of the derivatized product,m/z 174.1>114.1*,showed a good linear correlation with concentration(R2>0.9993).When the added concentration of penicillin G in blank samples were the limit of quantitation(LOQ),0.5 MRL,1.0 MRL,and 2.0 MRL,the recovery was 81.36%-96.18%in poultry tissues and pork;the intra-day RSD was 2.05%-4.52%,the inter-day RSD was 2.87%-5.36%;the limit of detection(LOD)was 1.50-4.10 μg/kg(S/N≥3),and the limit of quantitation(LOQ)was 4.50～8.20μg/kg(S/N≥10),respectively.The recovery of penicillin G in chicken eggs and duck eggs(whole egg,albumen,yolk)was 80.31%～94.50%;the intra-day RSD was 2.13%～4.82%,the inter-day RSD was 2.74%-6.13%;the limit of detection(LOD)was 1.70～3.20μg/kg(S/N≥3),and the limit of quantitation(LOQ)was 6.10-8.50 μg/kg(S/N>10),respectively.In conclusion,TMSD was selected as the derived reagent which was safe and stable.ASE extraction method was applied in this experiment which optimized the sample pretreatment process and improved the extraction efficiency.GC-MS/MS method was established for penicillin G residues in poultry eggs and pork.This method is of accurate qualitative and quantitative detection and high sensitivity,and the validation parameters of this method meet the drug residue requirements of the Ministry of Agriculture and the European Union. |
