同位素内标-超高效液相色谱-串联质谱法测定水产品中3种喹诺酮类兽药残留的不确定度评定

目的评定同位素内标-超高效液相色谱-串联质谱法测定水产品中3种喹诺酮类兽药残留的不确定度。方法按照农业部1077号公告-1—2008《水产品中17种磺胺类及15种喹诺酮类药物残留量的测定液相色谱-串联质谱法》测定水产品中恩诺沙星、环丙沙星和氧氟沙星3种喹诺酮类兽药残留。建立数学模型,分析和评定标准溶液配制、标准曲线拟合、样品称量、样品溶液制备和测量重复性等因素。结果水产品中恩诺沙星、环丙沙星和氧氟沙星残留量分别为18.8、9.04、6.56μg/kg时,其扩展不确定度分别为1.55、0.920、1.06μg/kg(k=2)。结论测量不确定度的主要来源是测量重复性、标准曲线的拟合与标准溶液的配制等过程,在实际检测过程中应加以控制。

Uncertainty evaluation for the determination of three quinolone residues in aquatic products by isotope internal standard-ultra performance liquid chromatography-tandem mass spectrometry

Objective To evaluate the uncertainty of determination of three quinolones residues in aquatic products by isotopic internal standard-ultra liquid chromatography-tandem mass spectrometry.Methods The residues of enoxacin,ciprofloxacin and ofloxacin in aquatic products were determined according to the Announcement of the Ministry of Agriculture No.1077-1—2008 Determination of 17 sulfonamides and 15 quinolones residues in aquatic products-Liquid chromatography-tandem mass spectrometry.A mathematical model was established to analyze and evaluate the factors such as preparation of standard solution,fitting of standard curve,sample weighing,sample solution preparation and measurement repeatability.Results When the residual amounts of enoxacin,ciprofloxacin and ofloxacin in aquatic products were 18.8,9.04 and 6.56μg/kg respectively,the extended uncertainty were 1.55,0.920 and 1.06μg/kg respectively(k=2).Conclusion The main sources of measurement uncertainty are measurement repeatability,fitting of standard curve and preparation of standard solution,which should be controlled in the actual detection process.