超声浸提-电感耦合等离子体原子发射光谱内标法测定离子型稀土矿区土壤中有效硫

离子型稀土矿在开采过程中由于浸矿液的注入,使得大量的硫进入到周边土壤中,影响着矿区的环境生态以及生物代谢。土壤中有效硫的准确测定对于离子型稀土矿区环境监测及保护、采矿迹地和尾砂废弃地的土壤修复以及植被重建具有重要意义。实验采用超声浸提结合电感耦合等离子体原子发射光谱(ICP-AES)内标法建立了测定离子型稀土矿区土壤中有效硫的分析方法。通过超声浸提条件选择试验,确定以磷酸盐-乙酸作为浸提剂,超声浸提时间为15min,解决了传统振荡提取耗时长的问题;选择S 182.0nm作为测定谱线,以2mg/L的铼标准溶液作为内标,采用电感耦合等离子体原子发射光谱法进行测定,相比于有效硫测定行业标准方法,大大缩短了分析流程。实验结果表明,有效硫在0.10~20.0mg/L质量浓度范围内线性关系良好,相关系数达到0.9999以上;方法检出限为0.08mg/kg。用土壤有效态成分分析标准物质进行方法精密度和正确度验证,测定值与标准值相符,相对标准偏差(RSD,n=5)小于2%。同时,用实验方法和行业标准方法对离子型稀土矿区中不同类型土壤中的有效硫进行了对照分析,测定结果一致,说明实验方法可为矿区环境中有效硫的监测提供快速准确的数据支持。

Determination of available sulfur in soil from ionic rare earth ore area by inductively coupled plasma atomic emission spectrometric inner standard method with ultrasonic leaching

During the mining process of ionic rare earth ore, a large amount of sulfur entered into the surrounding soil due to the injection of leaching solution of ore, which affected the environmental ecology and biological metabolism of ore area. The accurate determination of available sulfur in soil was of great significance for the environmental monitoring and protection of ionic rare earth ore area, the soil restoration and vegetation reconstruction of mining and tailings wasteland. A determination method of available sulfur in soil from ionic rare earth ore area by inductively coupled plasma atomic emission spectrometric inner standard method with ultrasonic leaching was established. The ultrasonic extraction conditions were tested and selected: phosphate-acetic acid was used as the leaching agent; the ultrasonic extraction time was 15min, which solved the problem of long time required for traditional shaking extraction; S 182.0nm was selected as the analytical line and 2mg/L of rhenium standard solution was used as the internal standard. The use of inductively coupled plasma atomic emission spectrometer (ICP-AES) greatly shortened the analytical procedures compared to the standard industrial method for the determination of available sulfur. The experimental results showed that the linearity was good for available sulfur in concentration range of 0.10-20.0mg/L, and the correlation coefficient was above 0.9999. The limit of detection was 0.08mg/kg. The precision and trueness were verified with certified reference materials of soil for available state component analysis, and the results were consistent with the standard values. The relative standard deviation (RSD, n=5) was less than 2%. Meanwhile, the proposed method and the industry standard method were both used to analyze the available sulfur in different types of soil from the ionic rare earth ore area for comparison analysis, and the results were consistent. It indicated that the proposed method could provide rapid and accurate data support for the environmental monitoring of available sulfur from ore area environment.