摘要
为了提高土壤阳离子交换量(CEC)测定结果的准确性,优化实验效率和环境友好性,考虑到现有标准方法的不足之处,对空白、浸提等实验步骤进行了优化,讨论了土壤样品称样量、浸提液使用体积和超声浸提时间在测定CEC时存在的影响。优化后的浸提时间由1 h缩短至10 min,液固比不变,土壤样品称样量从3.5 g减少到2.1 g,浸提液使用体积从50 mL减少到30 mL,不仅节约了前处理时间,还降低了样品和试剂的消耗量。该方法在二氯化六氨合钴溶液浓度为0~1.49 cmol/L范围内线性良好,相关系数(r)=0.999 9,方法检出限为0.8 cmol+/kg,测定下限为3.2 cmol+/kg;重复6次测定土壤实际样品,相对标准偏差为1.2%~3.5%;重复6次测定土壤有证标准物质,实测值均在保证值范围内,相对误差为-4.3%~5.8%,方法精密度和正确度良好。该方法易于操作,用时短,样品试剂消耗量少,适用于测定大批量土壤CEC样品。
The research focused on improving the determination of soil cation exchange capacity in terms of accuracy,efficiency,and environmental sustainability.Existing standard methods have many deficiencies.This study optimized key experimental procedures such as blank tests and extraction steps.It investigated the impact of soil sample mass,extractant volume,and ultrasonic extraction duration on the measurement results.After optimization,the extraction time was cut from 1 h to 10 min,with the liquid-solid ratio unchanged.The soil sample mass was reduced from 3.5 g to 2.1 g,and the extractant volume from 50 mL to 30 mL.This reduced pretreatment time and saved reagents and samples.The new method showed great linearity in the 0~1.49 cmol/L(r=0.9999).Its detection limit was 0.8 cmol+/kg,and the quantification limit was 3.2 cmol+/kg.For real soil samples,the relative standard deviation in replicate analysis was 1.2%to 3.5%(n=6).Measurements of certified reference materials were within certified ranges,with relative errors ranging from-4.3%to 5.8%(n=6),proving their high precision and accuracy.The optimized method was simple,time-saving,and resource-efficient,making it suitable for the analysis of a large number of soil samples.
作者
戚明慧
赵旭辉
张付海
QI Minghui;ZHAO Xuhui;ZHANG Fuhai(Anhui Ecological and Environment Monitoring Center,Hefei,Anhui 230071,China)
出处
《环境监控与预警》
2026年第1期55-59,共5页
Environmental Monitoring and Forewarning
基金
生态环境部大气重污染成因与治理攻关项目(DQGG202116)
安徽省重点研发计划(202304a05020010)。
关键词
土壤
阳离子交换量
三氯化六氨合钴
超声浸提
分光光度法
Soil
Cation exchange capacity
[Co(NH 3)6]Cl 3
Ultrasonic extraction
Spectrophotometric determination
