摘要
土壤重金属前处理消解过程的每一步都有其重要意义,对分析结果影响也十分显著,但耗时耗力。基于目前较新发布的土壤分析方法和四酸全分解体系,使用全自动石墨消解仪进行土壤样品的前处理,探索并优化消解程序,增加了消解后赶酸步骤。对消解后的样品使用火焰原子吸收分光光度计测定其中的铜和锌元素含量。通过比较各方法的测定结果,发现样品测定值与标准土壤认定值相对误差范围为-6.0%~2.7%,相对标准偏差为0.6%~4.8%。对不同质量的标准土壤样品测定结果表明,不同的消解方法对土壤样品影响较为明显。加酸消解预处理时,用四酸[10 mL(HCl)+10 mL(HNO3)+10 mL(HF)+3 mL(HClO4)]消解后加去离子水赶酸,精密度、准确度高,适用范围广。根据土壤有机质含量高低再辅以加硝酸浸泡过夜,可适用于多类型的土壤样品全分解。这一前处理过程人工操作较为简单,在保证质量与安全的同时,提升了样品处理量和工作效率。
Each step of the digestion process has its important meaning in the pretreatment of soil heavy metals and has a significant impact on the analysis results,but this process is quite time-consuming and labor-intensive.Based on the newly released soil analysis method and the four-acid total decomposition system,this study used an automatic graphite digestion instrument to pre-process soil samples.The digestion procedure was explored and optimized,and the acid removal step after digestion was added.The flame atomic absorption spectrometry was used to measure the copper and zinc content in soil after digestion.By comparing the measurement results with the soil standard values,the relative error was found to be between-6.0%and 2.7%,and the relative standard deviation was between 0.6%and 4.8%.Different methods have significantly different measurement precision for soil samples of different weight gradient.Generally speaking,the pretreatment with tetra-acids of10 mL HCl+10 mL HNO3+10 mL HF+3 mL HClO4 plus twice of acid digestion with deionized water has high comprehensive precision and accuracy,and is applicable to soil samples of various weighing gradients.According to the level of soil organic matter,supplemented with nitric acid soaking overnight,it is suitable for the digestion of many types of soil samples.The whole pre-treatment process is relatively simple to operate manually,but it greatly improves the handling capacity and work efficiency while ensuring quality and safety in the soil heavy metal measurement.
作者
张飙为
刘旺
何巍
章梦圆
孙文婷
ZHANG Biaowei;LIU Wang;HE Wei;ZHANG Mengyuan;SUN Wenting(Chongqing New World Environment Detection Technology Co.,Ltd.,Chongqing 401120,China;Chongqing Kaiyuan Environment Monitoring Co.,Ltd.,Chongqing 400202,China;Chongqing Mizhoulianfa Test Technology Co.,Ltd.,Chongqing 400202,China)
出处
《三峡生态环境监测》
2021年第4期32-38,共7页
Ecology and Environmental Monitoring of Three Gorges
关键词
土壤重金属
前处理
自动石墨消解仪
程序优化
heavy metals in the soil
pretreatment
automatic graphite digestion instrument
optimization of the program
