固相萃取-液相色谱串联质谱法同时测定养殖海水中17种喹诺酮类药物

Simultaneous Determination of Seventeen Quinolones in Aquaculture Seawater Using Solid-Phase Extraction and Liquid Chromatography Tandem Mass Spectrometry

关键词:  喹诺酮类药物  固相萃取  液相色谱-串联质谱  养殖海水

Key words:  Quinolones  Solid-phase extraction (SPE)  Liquid chromatography tandem mass spectrometry (LC-MS/MS)  Aquaculture seawater

摘要:

建立了固相萃取-液相色谱串联质谱法(SPE-LC-MS/MS)同时检测养殖海水中17种喹诺酮类药物残留的分析方法。海水经酸化处理后，采用HLB固相萃取柱富集、净化目标化合物，通过对比水样在不同上样pH、淋洗液与洗脱液等条件下的回收率，以此对前处理方法进行优化。收集到的洗脱液经氮气吹干后用流动相定容至1 ml，待测。色谱流动相A相为0.1%甲酸水溶液，B相为乙腈，所有药物经梯度洗脱进行分离，在LC-MS/MS正离子模式的多反应监测模式下进行定性定量分析。17种化合物可以在10 min中内得到较好的分离，线性范围为1–200 ng/ml，线性相关系数均大于0.999，检出限均在2–10 ng/L范围内，定量限均在5–20 ng/L范围内。以空白海水为基质，在20、100、200 ng/L三个不同添加水平下采用内标法定量的加标回收率均在71.3%–125.0%范围内，相对标准偏差(RSD)为2.44%–12.27% (n=5)。采用该方法对黄海灵山湾近岸4个养殖场进行海水采集并检测，共检测出4种喹诺酮类药物，分别是恩诺沙星、氧氟沙星、诺氟沙星和环丙沙星，其中，恩诺沙星浓度最高。研究表明，该方法快速、可靠，适用于养殖海水中喹诺酮类药物的检测。

Abstract:

In this study, we developed a method to determine 17 kinds of quinolones residues in aquaculture seawater by using solid-phase extraction and liquid chromatography tandem mass spectrometry (SPE-LC/MS/MS). The target antibiotics in water samples were enriched and cleaned-up by solid-phase extraction cartridges after the acidification with hydrochloric acid. We compared the sample recovery under different conditions to find the optimal pH of the loading buffer and the most suitable type and volume of the eluent. The elute was collected and concentrated under a gentle stream of nitrogen gas, and then dissolved into 1 ml liquid by the mobile phase. All antibiotics were separated by gradient elution with the mobile phase of 0.1% formic acid in water and acetonitrile. The targets were then analyzed by LC-MS/MS under the positive electrospray ionization condition in the multiple-reaction-monitoring (MRM) mode. Seventeen kinds of antibiotics can be separated successfully within 10 minutes. Calibration curves for antibiotics exhibited good linearity in the concentration range from 1 to 200 ng/ml and the correlation coefficients were larger than 0.999. The limits of detection (LOD) were 2-10 ng/L and the limits of quantification (LOQ) were 5-20 ng/L. The average recoveries of 17 quinolones at the spiked concentrations of 20 ng/L, 100 ng/L and 200 ng/L were 71.3% to 125.0% with a relative standard deviation (RSD, n=5) of 2.44% to 12.27%. This new method was applied to the analysis of four mariculture farms located in the Lingshan Bay of Qingdao in China. The results showed that four kinds of quinolones were detected including enrofloxacin, ofloxacin, norfloxacin and ciprofloxacin, and the highest concentration was 6880.05 ng/L. These results suggested that the new method was efficient and reliable, which was suitable for the detection of quinolones in seawater samples.