固相萃取-液相色谱-串联质谱法测定地下水中5大类44种抗生素

Simultaneous Determination of 44 Antibiotic in 5 Categories in Groundwater by Solid-phase Extraction-liquid Chromatography-tandem Mass Spectrometr

建立固相萃取-液相色谱-串联质谱法测定地下水中44种抗生素。调节样品pH值为3,加入质量浓度为0.5 g/L Na_(2)EDTA,用5 mL 0.1%甲酸-甲醇和3 mL 5%氨水-甲醇以流速为2 mL/min洗脱,动态多反应监测分析。结果表明,44种抗生素在质量浓度为0~50μg/L时,线性相关系数大于0.990,方法检出限为0.05~0.90 ng/L,加标回收率为39.1%~143%,RSD为1.9%~14%。采用该方法测定苏北某地地下水,检出18种抗生素(质量浓度为ND~21.7 ng/L)。

A method combining solid-phase extraction with liquid chromatography-tandem mass spectrometry was developed for the detection of 44 antibiotics in groundwater.The optimal parameters were as follows:the water was eluted at a rate of 2 mL/min with 5 mL of 0.1%formate-methanol and 3 mL of 5%ammonia-methanol by adjusting the pH of the sample to 3 and adding 0.5 g/L Na_(2)EDTA.The samples were quantified using dynamic multiple-reaction monitoring mode.The antibiotics showed satisfactory linearity within the 0~50.0μg/L range,with linear correlation coefficients all greater than 0.990.The method detection limits ranged from 0.05 to 0.9 ng/L.The average recoveries of the antibiotics were in the range of 39.1%~143%,with relative standard deviations(RSD)ranging from 1.9%to 14%.Finally,the optimized method was successfully applied to analyze ground water samples collected from northern Jiangsu.The results indicated that the 18 antibiotics could be detected at concentrations ranging from not detected(ND)to 21.7 ng/L.