混合酸消解变化影响原子荧光法测定土壤和沉积物中砷元素

Influence of Mixed Acid Digestion on Determination of Arsenic in Soil and Sediment by Atomic Fluorescence Spectrometry

为改进现有国家标准(HJ 680-2013)检测方法,以水浴法消解处理样品,采用原子荧光法测定土壤和沉积物中痕量砷。以国家一级土壤成分分析标准物质GSS-17,GSS-23,ESS-5与台州农业、建筑用土和管道淤泥沉积物样品为试验对象,探讨10种混合酸消解体系对复杂样品痕量砷测定结果的影响,筛选得到检测痕量砷含量的最佳实验条件。以盐酸-硝酸-硫酸(体积比为1∶3∶1)三酸体系为消解液,采用水浴法消解样品,消解时间为1.0h,总处理时间为2.5h。砷的质量浓度在0.1~10.0μg/L范围内具良好线性关系,线性相关系数大于0.999,检出限为0.008 mg/kg,检测下限为0.024 mg/kg,测定结果的相对标准偏差为0.66%~1.02%,回收率为90.2%~98.7%。该方法经国家一级土壤成分分析标准物质验证,准确可靠,已应用于农业、建筑用土和管道淤泥沉积物中痕量砷的测定,单次可批量处理72~84个样品,解决了高通量样品痕量砷测定需求。

In order to improve the existing national standard test method(HJ 680-2013),the samples were digested by water bath method,and the trace Arsenic in soil and sediment was determined by atomic fluorescence spectrometry.Taking GSS-17,GSS-23,ESS-5 as the national standard materials for soil composition analysis and Taizhou agricultural,construction soil and pipeline sludge sediment samples as the test objects,the influence of 10 mixed acid digestion systems on the determination results of trace Arsenic in complex samples was discussed,and obtain the optimal experimental conditions for the determination of trace Arsenic.The hydrochloric acid,nitric acid and sulfuric acid(volume ratio was 1∶3∶1)was used as the digestion solution,and the sample was digested by water bath method.The digestion time was 1.0h and the total treatment time was 2.5h.The mass concentration of Arsenic is in the range of 0.1~10.0μg/L and it has a good linear relationship,the linear correlation coefficient is more than 0.999,the limit of detection(LOD)is 0.008 mg/kg,the limit of quantitation(LOQ)is 0.024 mg/kg,the relative standard deviation of the determination results is 0.66%~1.02%,and the recovery of the sample is 90.2%~98.7%.This method has been verified by the national first-class standard material of soil composition analysis,which is accurate and reliable.It has been applied to the pretreatment of agricultural,construction soil and pipeline sludge sediment samples in the environment.72~84 samples can be processed in batches at one time,which can meet the demand of high-throughput sample trace Arsenic determination.