在线固相萃取-液相色谱-串联质谱法测定环境水体中抗生素

Determination of antibiotics in surface water with liquid qhromatography-tandem mass spectrometry after online solid phase extraction

应用在线固相萃取-液相色谱-串联质谱联用技术,定量检测地表水和污水处理厂废水中四环素类、磺胺类、大环内酯类、喹诺酮类和其他常见类抗生素化合物。水样经在线固相萃取小柱富集后,用乙腈-0.1%甲酸-5 mmol/L甲酸铵溶液为流动相洗脱并直接进入C18反相色谱柱分离,大气压电喷雾离子化串联质谱检测,同位素内标法定量。28种抗生素化合物含量在1~200 ng/L范围内均具有良好的线性响应,检出限低于0.7 ng/L。河水和污水厂废水的加标回收率分别在28%＂120%和28%＂125%范围。研究了EDTA和p H对水样处理回收率的影响。

Using on-line solid-phase extraction and liquid chromatography tandem mass spectrometry（LC-MS /MS） technology, a method was established for determining 28 antibiotics which included tetracyclines,sulfonamides,macrocyclic lactones,quinolones and other common antibiotics in water. The samples of water were on-line extracted by SPE using small cartridges,then were eluted by mobile phase（acetonitrile and 0. 1%formic acid-5 m M ammonium formate solution） and then separated on a C18 column. A high performance liquid chromatography combined with tandem mass spectrometry（HPLC/MS/MS） using isotope dilution and internal standard quantitation techniques was used for determination,operating at positive electrospray ionization source（ESI ＋） by multiple reaction monitoring mode（MRM）. 28 antibiotics have good linear relationship in the range of 1 ~ 200 ng/L,and the detection limit of the method（measured 7 aliquot of a low concentration of sample,3. 14 times the standard deviation） was below 0. 7 ng/L. Spiked in river water（Pearl River Guangzhou section）and wastewater（sewage water） at concentration of 20 and 50 ng/L,the recoveries of antibiotics were 28% ~120% and 28% ~ 125%. The proposed method is simple, sensitive, automated, and suitable for rapid determination of trace antibiotics in environmental water samples.