摘要
土壤中全盐量测定过程中,由于部分土壤粘性大,导致样品处理过程中很难获得澄清的浸出液;部分土壤的浸出液颜色较深,对滴定终点的判断有一定的影响。为了解决这些问题,文章采用聚氧化乙烯作为絮凝剂富集浸出液中的胶体颗粒,通过离心、过滤等操作获得澄清的浸出液,分取浸出液采用重量法测定土壤样品中的全盐量。进行空白实验、絮凝剂的种类、用量和对离心时间的影响试验、过氧化氢的用量试验,建立以聚氧化乙烯作为絮凝剂测定土壤中全盐量的方法。实验的最佳条件为:称样量为50.0 g;浸提剂为250 mL无二氧化碳纯水;絮凝剂的种类和用量为:1 mL 0.5%的聚氧化乙烯溶液;离心时间为15 min;过氧化氢的用量为16 mL的过氧化氢溶液(1+1),加入方式为分8次及每次加入2 mL润湿残渣。在选定的实验条件下测定国家标准物质土壤样品中全盐量,测定结果的相对标准偏差为2.76%~4.37%(n=11),相对误差为0.76%~1.92%,本方法可以简化土壤全盐量中的样品处理过程,消除土壤浸出液中颜色对滴定终点的干扰,测定结果准确。
During the determination of the total amount of salt in the soil,it is difficult to obtain a clarified leaching solution due to the large viscosity of some soils during the sample processing.The leaching solution of some soils is dark in color,which has a certain effect on the judgment of the end point of titration in order to solve these problems,polyethylene oxide is used as a flocculant in this paper to concentrate colloidal particles in the leaching solution,and a clarified aching solution is obtained through operations such as centrifugation and filtration.The leaching solution is taken by the method of weight to determine the total amount of salt in the soil.The blank experiment,the type and amount of flocculant and the influence of centrifugation time are tested,and the method to determine the total amount of salt in the polyethylene oxide as the flocculant is established.The optimal conditions for the experiment are as followed.Sample weight of 50.0 g,leaching agent of 50 mL of water without carbon dioxide,type and amount of flocculant:1 mL of 0.5%polyethylene oxide solution,centrifugation of 15 min,amount of hydrogen peroxide 16 mL of hydrogen peroxide solution(11),added in a way that is divided into times and each time 2 mL is added to wet the residue.Under the selected experimental conditions,for the total amount of salt in the soil sample of the National Standard Material,the relative standard deviation of the determination results is 2.76%~4.37%(n=11),the relative error is 0.76%~1.92%.This method can simplify the sample processing process in the total amount of soil salt,eliminate the interference of the color of soil leaching solution to the end point of titration,and the determination results are accurate.
作者
田松
尹昌慧
覃晓静
唐莉福
徐华
TIAN Song;YIN Changhui;QIN Xiaojing;TANG Lifu;XU Hua(China Nonferrous Metals(Guilin)Geology and Mining Co.,Ltd.,Guilin 541004,Guangxi,China)
出处
《矿产与地质》
2026年第1期212-216,共5页
Mineral Resources and Geology
基金
中国有色集团科技专项项目(编号:2023KJZX31)
中国有色桂林矿产地质研究院科技创新团队项目(编号:KJCXTD202412)
中国有色桂林矿产地质研究院科技创新基金项目(编号:KDYCXJJ202412)共同资助。
关键词
土壤
全盐量
聚氧化乙烯
絮凝剂
重量法
soil
total salt content
polyethylene oxide
flocculant
gravimetric method
