The Pharmacokinetics And Residual Characteristics Of Maduramicin In Red Swamp Crayfish

Maduramicin ammonium is a kind of polyether antibiotics extract from the fermentation of Actinobacillus.It is active for the sporozoites and first generation schizont of the coccidiosis.In addition,it can also promote the growth of poultry,improve dairy feed utilization.So,it is widely as feed additives.The abuse of antibiotics can cause environmental pollution and threat the health of humans and animals.Currently,there are few studies on pharmacokinetics and residues of maduramicin ammonium,but the research on pharmacokinetics and residue elimination in aquaculture animals is a blank.HPLC-MS/MS method was established in this study for determination of maduramicin ammonium in hemolymph,hepatopancreas and muscles of crayfish,and the regulation of pharmacokinetics and drug residue was investigated based on this method.1 Development of an ultra-performance liquid chromatography-tandem mass spectrometry method for the determination of maduramicin ammonium in the hemolymph of crayfishThe plasma sample is extracted with acetonitrile,chromatographic separation by Acquity UPLC(?)BEH C18 column(50 mmx2.1 mm,1.7 ?m).Analysis was carried out on UPLC-MS/MS working with multiple reaction monitoring mode.The limits of detection(LOD)and quantification(LOQ)in plasma were 6 and 20 ng-mL'1 respectively.The results showed that the drug in hemolymph showed good linear relationship at the range of 20?8000 ng·mL-1 and the correlation coefficients were greater than 0.99(R2>0.99),the standard curve was y=0.0976848x+0.743946.The mean average recoveries of spiked samples ranged from 93.1%to 107.8%with relative standard deviation(RSD)less than 10.1%.2 Pharmacokinetic test of maduramicin ammonium in crayfish156 male crayfishes were randomly divided into two groups,low dose group and high dose group,administrated at 350,700 g kg-1 bw,respectively.Each group collected the hemolymph of six crayfish randomly at 0.083,0.167,0.25,0.5,1,2,4,8,24,48,72,and 96h after dosage.Hemolymph samples were detected by UPLC-MS/MS and the pharmacokinetic was analyzed with WinNonLin 5.2.The parameters of high dose group were like this:Ti/2?z=28.75±9.81 h,Tmax=0.58±0.20 h,Cmax=289.55±156.2 ng·ML-1;The parameters of loe dose group were listed like this:Ti/2?z=31.80±7.98 h,Tmax=0.42±0.13 h,Cmax=88.29±61.23 ng·mL-1.3 Development of an ultra-performance liquid chromatography-tandem mass spectrometry method for the determination of maduramicin ammonium in red swamp crayfish edible tissuesThe samples were extracted with acetonitrile,and then purified via an Oasis HLB solid-phase extraction cartridge.Chromatographic separation was performed on an Acquity UPLC BEH C18 column.Analysis was carried out on UPLC-MS/MS working with multiple reaction monitoring mode.Internal standard was used for quantitation.The method has a good linearity at the range of 20?000 pg·kg-1,the standard curve was y=0.0979752x+0.499055 and y=0.0891236x+0.65948,respectively.Recoveries of spiked samples ranged was from 74.2%to 110.4%with relative standard deviation(RSD)less than 10.1%.The limits of detection(LOD)and quantification(LOQ)were 6?g·kg-1 and 20 ?g·kg-1,respectively.4 Residue elimination test of maduramicin ammonium in crayfishThe crayfishes were bathed in the maduramicin ammonium solution to investigate the residue and elimination of maduramicin ammonium in the edible muscle and hepatopancreas.The duration of drug absorption and clear phase were 3 d and 5 d,respectively.The hepatopancreas and muscle tissues of crayfish were collected at different time points.Samples were extracted by acetonitrile.And then purified,concentrated,and detected by liquid chromatography tandem mass spectrometry.The result of this study shows that it takes three days for maduramicin ammonium to reach a steady concentration in tissues of crayfish after bath treatment.The elimination time of drugs in muscle and hepatopancreas was 3 d and 5 d,respectively.The concentration of drugs in the hepatopancreas was higher than that in the muscle.The results of the test analyzed with the software WT1.4 suggested that the withdrawal time of maduramicin ammonium was 25.8?·d.