Simultaneous determination of residues of amoxicillin and ampicillin in chicken excrement by HPLC with fluorescence detection

A high performance liquid chromatography with fluorescence detection method(HPLC-FLD)was developed for simultaneous determination of residues of amoxicillin(AMO)and ampicillin(AMP)in chicken excrement.AMO and AMP in chicken excrement were extracted with acetonitrile and saturated dichloromethane,and the derivatization was in salicylaldehyde/water bath(acid environment).The mobile phase was phosphate potassium dihydrogen solution(A)and acetonitrile(B).The gradient elution was at a flow rate of 1.0mL·min-1.The fluorescence was performed at an excitation wavelength of 354 nm and an emission wavelength of 445 nm.The concentrations of AMO and AMP were proved with good linear correlation at the range of 0.1to 250.0μg·g-1 and the correlation coefficients were 0.999 8for AMO and 0.999 8for AMP.At spiked levels of 5.0to 125.0μg·g-1 for AMO and AMP,sample recoveries ranged were higher than 71.52%and RSD were less than 9.77%.The detection and quantification for AMO was 3.0ng·g-1(S/N=3)and 6.0ng·g-1(S/N=10),respectively.The limits of detection and quantification for AMP was 1.2ng·g-1(S/N=3)and 3.5ng·g-1(S/N=10),respectively.This method is sensitive,accurate,simple,and rapid,and can meet the simultaneous detection of AMO and AMP residue in chicken excrement.