微波消解-原子吸收法测定土壤中的铬

Determination of Chromium in Soil by Microwave Digestion - atomic Absorption Spectrometry

采用微波消解-原子吸收法测定土壤中的铬,选用小麦地区域土壤作为检测对象,研究了不同消解体系下Cr元素含量,确定了最佳的消解体系,并验证了准确度和精确度。研究结果表明,当V(HNO3)∶V(HCl)∶V(H2O2)∶V(HF)为3∶1∶2∶1时,土壤重铬含量检测效果最佳。这是因为硝酸与盐酸形成的王水比例以及过氧化氢的引入使得其对有机物消解更为充分,同时,HF酸的加入能破坏硅酸盐晶格,使得内部的金属元素充分暴露出来。准确度验证实验表明,按照本文方法微波消解-原子吸收法测定土壤中Cr,得到线性方程y=0.0968x+0.0008,线性相关系数为0.9998,线性范围20~500 ng/mL,检出限1 ng/mL。RSD<1%,加标回收率为98%~103%。

In this paper,the microwave digestion-atomic absorption method was used for the determination of chromium in soil,and the soil in wheat field was selected as the test object.The content of Cr in different digestion systems was studied,and the best digestion system was determined,and the accuracy and accuracy were verified.The results showed that when V(HNO3):V(HCl):V(H2O2):V(HF)was 3∶1∶2∶1,the detection effect of dichromate content in soil was the best.This is because the ratio of aqua reticulum formed by nitric acid and hydrochloric acid and the introduction of hydrogen peroxide make its digestion of organic matter more adequate.Meanwhile,the addition of HF acid can destroy the silicate lattice,making the internal metal elements fully exposed.The accuracy verification experiment showed that the linear equation y=0.0968x+0.0008,the linear correlation coefficient was 0.9998,the linear range was 20~500 ng/mL,and the detection limit was 1 ng/mL.RSDS were less than 1%,and the recoveries ranged from 98 to 103%.