气量法测定土壤中碳酸盐含量的方法改进  

An improved method for the determination of carbonate content in soil by air volume method

作　　者：黄环 王朝晖 谷娟平 何金洋 HUANG Huan;WANG Zhaohui;GU Juanping;HE Jinyang(China Nonferrous Metal(Guilin)Geology and Mining Co.,Ltd.,Guilin 541004,Guangxi,China;Hezhou University,Hezhou 542899,Guangxi,China)

机构地区：[1]中国有色桂林矿产地质研究院有限公司,广西桂林541004 [2]贺州学院,广西贺州542899

出　　处：《矿产与地质》2024年第5期996-1000,共5页Mineral Resources and Geology

摘　　要：为简化测定土壤中碳酸盐含量的方法流程,本研究提出一种改进的气量法装置,用于批量化测定土壤中的碳酸盐含量。该方法将土壤样品置于带有搅拌子的锥形瓶中,通过真空泵对整个脱气装置抽真空至-0.1 MPa,并继续抽真空3 min,随后缓慢加入10 mL盐酸溶液并启动搅拌器。样品中的碳酸盐与盐酸反应释放出的二氧化碳通过管路经盛水的脱气管进入脱气管上端,当脱气管中的水柱不再变化,通过反应瓶上端的管路将水注入反应瓶及脱气管中,二氧化碳气体被驱赶至脱气管上端,通过注射器抽取并记录气体体积,将记录的体积换算成碳酸钙含量。本方法对国家标准物质和实际样品进行测定,并通过回收率实验验证其准确性。结果显示,相对标准偏差为1.42%~4.46%,回收率为97.3%~101.0%,且国家标准物质的测定结果均在认定值的不确定度范围内,表明该方法准确度高和重现性好。此外,该方法操作简单快捷,分析效率高,适用于土壤中碳酸盐含量的测定。In order to simplify the process of determination of carbonate content in soil,this study proposes an improved gas volume method device for batch determination of carbonate content in soil.In this method,the soil sample was placed in a conical flask with a stirrer,and the entire degassing device was vacuumized to-0.1 MPa by a vacuum pump,and the vacuum was continued for 3 min.Then,10 mL of hydrochloric acid solution was slowly added and the stirrer was started.The carbon dioxide released by the reaction of carbonate and hydrochloric acid in the sample enters the upper end of the detaching pipe through the detaching pipe containing water.When the water column in the detaching pipe does not change,the water is injected into the reaction bottle and the detaching pipe through the upper pipe of the reaction bottle,and the carbon dioxide gas is driven to the upper end of the detaching pipe.The gas volume is extracted and recorded by a syringe,and the recorded volume is converted into calcium carbonate content.The method was applied to the determination of national standard materials and actual samples,and the accuracy was verified by recovery experiments.The results showed that the relative standard deviation was 1.42%to 4.46%,the recovery rate was 97.3%to 101.0%,and the determination results of national standard materials were within the uncertainty range of the identified values,indicating that the method had high accuracy and good reproducibility.In addition,the method is simple and fast,and the analysis efficiency is high,which is suitable for the determination of carbonate content in soil.

关 键 词：气量法 碳酸盐 脱气装置 抽真空 

分 类 号：S153.6[农业科学—土壤学] O655[农业科学—农业基础科学]