液相色谱-串联质谱法同时检测水产养殖用投入品中3种酰胺醇类药物残留量OA

[Objective]In order to address the challenges associated with complex matrices,diverse product types,and the potential illegal addition of amphenicol antibiotics in aquaculture inputs,a sensitive and reliable analytical method was developed for the simultaneous determination of chloramphenicol(CAP),thiamphenicol(TAP),and florfenicol(FF)residues in aquaculture inputs,providing technical support for quality and safety su-pervision.[Methods]A liquid chromatography-tandem mass spectrometry method was established for the de-termination of CAP,TAP,and FF.Samples were extracted with ethyl acetate under alkaline conditions,fol-lowed by lipid removal using n-hexane liquid-liquid partitioning.The extracts were purified using C18 solid-phase extraction cartridges.Chromatographic separation was achieved on a reversed-phase C18 column,and de-tection was performed in negative electrospray ionization mode using multiple reaction monitoring(MRM).Quantification was carried out using an internal standard method.Key parameters,including extraction solvent,purification procedure,chromatographic conditions,and mass spectrometric parameters,were systematically op-timized.The method was validated in terms of linearity,limits of detection(LOD),limits of quantification(LOQ),recovery rate,and precision.[Results]Good linearity was obtained for all three analytes over the con-centration range of 0.50-20.0 ng/mL,with correlation coefficients greater than 0.999.The LODs ranged from 0.043 to 0.088 μg/kg,while the LOQs ranged from 0.14 to 0.29 μg/kg.Recovery experiments conducted at three spiking levels(1.00,2.50,and 5.00 μg/kg)in different aquaculture input matrices showed recovery rates ran-ging from 98.0%to 109%.The relative standard deviation(RSD)for intra-day precision ranged from 1.15%to 4.13%,and the RSD for inter-day precision ranged from 1.88%to 5.02%.Analysis of 24 batches of real aquaculture input samples revealed the presence of florfenicol in several samples,with concentrations ranging from 3.58 to 10.6 μg/kg,while chloramphenicol and thiamphenicol were not detected.[Conclusion]The de-veloped liquid chromatography-tandem mass spectrometry method demonstrates high sensitivity,good accur-acy,and excellent reproducibility for the determination of amphenicol residues in complex aquaculture input matrices.The method is suitable for large-scale screening and quantitative analysis and can be effectively ap-plied in routine regulatory monitoring and risk assessment of aquaculture inputs.