采用水平震荡和超声浸取2种方法进行预处理,离子选择电极法测定土壤中水溶性氟化物. 结果显示:土壤中水溶性氟化物的最佳预处理条件为纯水与土壤按10:1混合,常温35 kHz超声浸取30 min. 超声浸取-离子选择电极法测定土壤中水溶性氟化物具有较好的精密度和准确性,此法在5.00~500 μg范围内线性良好,检出限为0.5 mg/kg. 对实际样品进行分析,氟的加标回收率为82.0%~110%,相对标准偏差为2.8%~6.4%(n=6). 对土壤有证标准物质进行分析,相对标准偏差为2.9%~4.6%(n=6),相对误差为-3.9%~2.7%.%Fluoride in leaching solution of soil was extracted by horizontal vibration and ultrasonic method and then quantified by the ion selective electrode method .The experimental results showed that the best pretreatment conditions for water -soluble fluoride in soil were to mix purified water and soil in a ratio of 10:1, and then extract by ultrasonic leaching for 30 min under 35 kHz frequency at room temperature .The water-soluble fluoride in soil was determined by the ion selective electrode method with good precision and accuracy.The method had a good linearity for fluoride in the range of 5.00~500 μg, and the detection limit of 0.5 mg/kg.The recoveries ranged from 82.0%to 110%and the relative standard deviations were between 2.8%and 6.4%(n=6) in real sample determinations .The test results of certified reference materials in soil were qualified , the relative standard deviations were between 2.9%and 4.6%(n=6), and the relative errors between the results and the standard results were in the range of -3.9%~2.7%.
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