全国土壤污染状况详查重金属元素可提取态提取试剂的选择  

Screening of Extractable Reagents for Heavy Metal Elements in the Detailed Survey of Soil Pollution in China

作　　者：熊英[1] 王亚平[2] 韩张雄[1] 董亚妮[1] 蒋俊平[1] XIONG Ying;WANG Yaping;HAN Zhangxiong;DONG Yani;JIANG Junping(Xi’an Mineral Resources Supervision and Testing Center,Ministry of Land and Resources,Xi’an 710054,China;National Research Center for Geoanalysis,Beijing 100037,China)

机构地区：[1]国土资源部西安矿产资源监督检测中心,陕西西安710054 [2]国家地质实验测试中心,北京100037

出　　处：《岩矿测试》2022年第3期384-393,共10页Rock and Mineral Analysis

基　　金：中国地质调查局地质调查项目“全国土壤污染详查贵州福建等10省质量监控样制备及质量监督检查”(121201105000168509);陕西省地矿集团有限公司地质科研专项基金项目“陕西省质量监控样品制备——全国土壤污染详查”(KY201904)。

摘　　要：土壤重金属元素可提取态是衡量其生物有效性的重要指标,但其含量随着土壤酸碱性等环境条件的变化而改变,在提取土壤重金属元素可提取态时,不可避免地面临着提取剂与提取方法的选择。中国有关土壤重金属元素可提取态的标准分析方法或技术规范涉及的提取剂多达7种(pH=5.8盐酸溶液、0.1mol/L盐酸溶液、0.43±0.02mol/L硝酸溶液、0.11mol/L乙酸溶液、1mol/L硝酸铵溶液、0.005mol/L DTPA浸提剂、0.01mol/L氯化钙溶液),不同学者对不同提取剂有不同的研究结论,对于通用提取剂的系统研究未见报道。本文选择代表性农耕土壤样品,采用以上7种提取剂提取其中8种重金属元素(镉镍铜锌铬铅砷汞),电感耦合等离子体质谱法(ICP-MS)测定镉铬铜铅锌镍含量,原子荧光光谱法(AFS)测定砷和汞含量,对比了7种提取剂对各重金属元素的提取率,并研究了土壤酸碱性质对重金属元素提取率的影响。结果表明:①稀酸溶液对土壤重金属元素的提取率较高,且与土壤的酸碱性无关;②1mol/L硝酸铵溶液虽然对镉的提取能力表征了镉在酸性土壤中的活性远大于碱性土壤的特点,但其对碱性土壤中铅的提取率大于镉;③DTPA提取剂对各重金属元素(尤其是铅、铜、锌)的提取率均显著高于0.01mol/L氯化钙溶液,且提取率随土壤酸碱性质的变化不显著;④0.01mol/L氯化钙溶液对镉的提取率最高,且与土壤酸碱性质密切相关,是土壤重金属元素可提取态较为理想的通用提取剂。BACKGROUND:The extractable state of soil heavy metal elements is an important index to measure their bioavailability,but its content changes with soil acid-base properties and other environmental conditions.When determining which method to use for the extractable state of soil heavy metal elements,there are more than 7 kinds of extraction reagents involved in relevant standard methods or technical specifications.These include hydrochloric acid of pH=5.8,0.1mol/L hydrochloric acid,0.43±0.02mol/L nitric acid,0.11mol/L acetic acid,1mol/L ammonium nitrate solution,0.005mol/L DTPA leaching agent,0.01mol/L calcium chloride solution.Different scholars have different research conclusions on different extractants.There is no systematic research report on extractants suitable for different soil types.OBJECTIVES:To select and determine the general extractant suitable for the extractable state of heavy metal elements in soil with different acid-base properties.METHODS:Using typical farming soil samples as the research objective,7 kinds of extracting agent were used to extract 8 heavy metals(Cd,Ni,Cu,Zn,Cr,Pb,As and Hg).Inductively coupled plasma-mass spectrometry(ICP-MS)was used to determine Cd,Cr,Cu,Pb,Zn,Ni,whereas atomic fluorescence spectrometry(AFS)was used to determine As and Hg.The extraction rates of 7 kinds of extractants were compared,and the effects of soil acid and alkali properties on the extraction rate of heavy metal elements were studied.RESULTS:Dilute acid solution had a strong ability of leaching heavy metals from soil,and it was not related to the acidity and alkalinity of the soil.Although the extraction ability of 1mol/L ammonium nitrate solution for cadmium indicated that the activity of cadmium in acidic soil was much higher than that in alkaline soil,its extraction rate of lead in alkaline soil was higher than that of cadmium.The extraction rate of DTPA extractant for soil heavy metal elements was significantly higher than that of 0.01mol/L calcium chloride solution,especially for lead,copper and zin

关 键 词：土壤 重金属元素可提取态 提取剂 电感耦合等离子体质谱法 原子荧光光谱法 生物有效性系数 氯化钙提取法 

分 类 号：O657.63[理学—分析化学] S151.93[理学—化学]