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    分散固相萃取-高效液相色谱-串联质谱法测定鱼塘底泥中氯硝柳胺的含量

    Determination of Niclosamide in Fish Pond Sediments by High Performance Liquid Chromatography-Tandem Mass Spectrometry with Dispersive Solid Phase Extraction

    • 摘要: 为简化前处理过程,降低方法的检出限,进行了题示研究。采集鱼塘底泥样品,混匀、缩分、冷冻干燥、除杂、研磨、过筛后混匀,分取5.00 g,加入10.0 μg·L−113C6-氯硝柳胺水合物标准溶液0.2 mL和含2.0%(体积分数)氨水的乙腈溶液20 mL,涡旋1 min,超声10 min,离心8 min。上清液于45 ℃旋蒸至近干,加入2.00 mL 70%(体积分数)乙腈溶液涡旋溶解残留物,再加入200 mg C18涡旋振荡30 s,离心5 min。收集上清液,过0.22 μm 有机滤膜,滤液采用高效液相色谱-串联质谱法测定。在色谱分析中,以Waters AtiantisTM dC18色谱柱为固定相,水-乙腈体系为流动相进行梯度洗脱;在质谱分析中,以电喷雾离子源负离子(ESI)模式电离,选择反应监测(SRM)模式检测,内标法定量。结果显示,氯硝柳胺的质量浓度在0.20~50.00 µg·L−1内和其定量离子峰面积与同位素内标定量离子峰面积的比值呈线性关系,检出限(3S/N)为0.2 µg·kg−1。按照标准加入法进行回收试验,回收率为92.1%~113%,测定值的相对标准偏差(n=6)为1.6%~5.9%。方法用于实际样品的分析,检出的氯硝柳胺的质量分数为0.580~2.18 mg·kg−1

       

      Abstract: To simplify the pre-processing process and reduce the detection limit of the method, the study mentioned by the title was conducted. Sediment samples were collected from fish ponds, mixed well, split, freeze-dried, removed from impurities, ground, and sieved. After mixing well, an aliquot (5.00 g) was taken, and 0.2 mL of 10.0 μg·L−113C6-niclosamide hydrate standard solution and 20 mL of acetonitrile solution containing 2.0% (volume fraction) aqueous ammonia were added. The mixture was vortexed for 1 min, sonicated for 10 min, and centrifuged for 8 min. The supernatant was rotary evaporated to near dryness at 45 ℃, and 2.00 mL of 70% (volume fraction) acetonitrile solution was added to dissolve the residue by vortex. Then, 200 mg of C18 was added, and the mixture was vortexed for 30 s, and centrifuged for 5 min. The supernatant was collected and passed through a 0.22 μm organic filter membrane, and the filtrate was determined by high performance liquid chromatography-tandem mass spectrometry. In chromatographic analysis, the Waters AtiantisTM dC18 column was used as the stationary phase, and the water-acetonitrile system was used as the mobile phase for gradient elution. In the mass spectrometry analysis, the negative ion (ESI) mode of the electrospray ion source was used for ionization, the selected reaction monitoring (SRM) mode was used for detection, and the internal standard method was used for quantification. It was shown that linear relationship between values of the mass concentrations of niclosamide and peak area ratios of quantitative ions between niclosamide and isotope internal standard was kept in the range of 0.20-50.00 µg·L−1, with detection limit (3S/N) of 0.2 µg·kg−1. Test for recovery was made according to the standard addition method, giving recoveries in the range of 92.1%-113%, and RSDs (n=6) of the determined values ranged from 1.6% to 5.9%. The proposed method was used for the analysis of actual samples, and the mass fraction of niclosamide detected was found in the range of 0.580-2.18 mg·kg−1.

       

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