超声溶剂萃取-流动注射分析法测定水源水底泥中氨氮污染物

Determination of ammonia nitrogen in environmental sediment by ultrasonic solvent extraction-flow injection analysis

目的 基于超声溶剂萃取-连续流动注射仪分析技术,建立一种简便、快速测定生活饮用水源水底泥中氨氮含量的检测方法。方法 底泥样品经真空冷冻干燥后,以2.0 mol/L氯化钾水溶液为溶剂,超声提取底泥样品中的氨氮化合物,离心后用全自动流动注射分析仪测定上清液中氨氮的含量。结果 氨氮污染物标准曲线的线性范围是0.02~2.0 mg/L,相关系数(r)为0.999 95,方法检出限为0.1 mg/kg。测定结果的相对标准偏差为1.48%(n=7),样品加标回收率为82.6%~106.7%。结论 本研究建立的分析方法具有准确、灵敏、分析速度快和自动化程度高的优点,检测结果精密度和准确度高,克服了传统滴定分析方法工作效率低,操作繁琐等缺点。

Objective To establish a simple and rapid method for the determination of ammonia nitrogen in the bottom sediment of drinking water sources based on ultrasonic solvent extraction and continuous flow injection instrument analysis technology.Methods After vacuum freeze-drying,ammonia nitrogen compounds in sediment samples were extracted by ultrasound with 2.0mol/L potassium chloride aqueous solution as solvent.The supernatant was taken after centrifugation,and the content of ammonia-nitrogen in the samples was determined by automatic flow injection analyzer.Results The linear range of the standard curve was 0.02-2.0 mg/L,the correlation coefficient(r) was 0.999 95,and the detection limit of the method was 0.1 mg/kg.The relative standard deviation of the determination results was 1.48%(n=7),and the spiked recoveries were 82.6%-106.7%.Conclusion The analysis method established in this study has the advantages of accuracy,sensitivity,fast analysis speed and high degree of automation.The precision and accuracy of the test results are high,which overcomes the shortcomings of low efficiency and tedious operation of traditional titration analysis.