乙醇和氯化铵提取-原子吸收光谱法测定石灰性土壤中的交换性钾、钠、钙、镁  

Determination of exchangeable potassium,sodium,calcium and magnesium in calcareous soil by atomic absorption spectrometry with ethanol and ammonium chloride extraction

作　　者：席秀丽 高艳敏 王生进[1] 刘春虎 XI Xiuli;GAO Yanmin;WANG Shengjin;LIU Chunhu(The ninth geological Brigade of Hebei Bureau of Geology and Mineral Exploration and Development,Xingtai 054000,China)

机构地区：[1]河北省地质矿产勘查开发局第九地质大队,河北邢台054000

出　　处：《化学分析计量》2024年第1期58-64,共7页Chemical Analysis And Meterage

摘　　要：建立乙醇和氯化铵提取-原子吸收分光光度法测定石灰性土壤中的交换性钾、钠、钙、镁。采用乙醇和氯化铵对石灰性土壤进行处理,以离心分离的方式对石灰性土壤中易溶的氯化物和硫酸盐进行清洗及交换性钾、钠、钙、镁离子的提取,提取液以原子吸收分光光度计测定。交换液pH为8.5,乙醇体积分数为70%,氯化铵浓度为0.1 mol/L。交换性盐基钾、钠、钙、镁的质量浓度分别在0~10、0~2.5、0~40、0~5.0 mg/L范围内与吸光度线性关系良好,相关系数均大于0.9990,方法检出限分别为0.06、0.10、0.21、0.04 mmol/kg。样品加标回收率为97.0%~104%,测定结果的相对标准偏差为2.81%~5.85%(n=6)。采用所建方法对土壤有效态成分分析标准物质GBW(E)070336进行测定,测定结果的相对误差为0.40%~6.67%。该方法快速,适用于石灰性土壤中交换性钾、钠、钙、镁的测定。A method for the determination of exchangeable potassium,sodium,calcium and magnesium in calcic soil by atomic absorption spectrophotometry with ethanol and ammonium chloride extraction was established.The calcareous soil was treated with ethanol and ammonium chloride.The soluble chloride and sulfate in the calcareous soil were cleaned by centrifugal separation,and the exchangeable potassium,sodium,calcium and magnesium ions were extracted.The extracted solution was determined by atomic absorption spectrophotometer.The pH of the exchange solution was 8.5,the volume fraction of ethanol was 70%and the concentration of ammonium chloride was 0.1 mol/L.The mass concentrations of exchangeable base potassium,sodium,calcium and magnesium had a good linear relationship with the absorbance in the range of 0-10 mg/L,0-2.5 mg/L,0-40 mg/L,0-5.0 mg/L,respectively,the correlation coefficients were all more than 0.9990,and the detection limits were 0.06,0.10,0.21,0.04 mmol/kg,respectively.The recoveries of the samples were 97.0%-104%,and the relative standard deviations of the determination results were 2.81%-5.85%(n=6).The established method was used to determine the standard substance GBW(E)070336 for soil active component analysis,and the relative error of the determination results was 0.40%-6.67%.The method is rapid and it is suitable for the determination of exchangeable potassium,sodium,calcium and magnesium in calcareous soil.

关 键 词：石灰性土壤 乙醇 氯化铵 交换性钾 交换性钠 交换性钙 交换性镁 原子吸收光谱法 

分 类 号：O657.3[理学—分析化学]