超声提取-离子色谱法测定银精矿中水溶性氟

银精矿中水溶性氟会随雨水的冲刷进入生物圈,直接对土壤、水体、大气、人类健康产生危害。实验提出超声提取-离子色谱法测定银精矿中水溶性氟,为银精矿中水溶性氟的检测及后续环境影响评估提供重要的技术支撑。称取0.2g样品(过150目筛),加入30mL水,在40℃时超声提取20min后,使用阴离子交换柱进行分离,使用碳酸钠-碳酸氢钠混合溶液作为淋洗液进行淋洗,洗脱时间为25min,通过电导检测器进行F^-检测。F^-质量浓度在0.5~10mg/L范围内与对应的峰面积呈线性关系,校准曲线线性相关系数为0.9998;方法检出限为0.062mg/L,测定下限为0.21mg/L。按照实验方法测定两个银精矿中水溶性氟,测定结果的相对标准偏差(RSD,n=6)为3.8%和4.3%;加标回收率为92%~102%。

Determination of water-soluble fluoride in silver concentrate by ion chromatography with ultrasonic extration

The water-soluble fluoride (F^-) in silver concentrate can enter into biosphere with rainwash and directly cause harm to the soil, water system, atmosphere and human being. The determination of water-soluble fluoride in silver concentrate by ultrasonic extraction-ion chromatography was proposed. It provided important technical support for the detection of water-soluble fluoride in silver concentrate and subsequent environmental impact assessment. 0.2g of sample (passing through 150-mesh sieve) was added into 30mL of water. After ultrasonic extraction at 40℃ for 20min, the anion exchange column was employed for separation. The mixture solution of sodium carbonate-sodium bicarbonate was used as leacheate for elution. The elution time was 25min. The content of water-soluble fluoride was detected by electrical conductivity detector. The mass concentration of F^- in range of 0.5-10mg/L was linear to the corresponding peak area. The linear correlation coefficient of calibration curve was 0.9998. The detection limit was 0.062mg/L and the low limit of determination was 0.21mg/L. The content of water-soluble fluoride in two silver concentrate samples was determined according to the experimental method. The relative standard deviation (RSD, n=6) of determination results was 3.8% and 4.3%, respectively. The recoveries were between 92% and 102%.