涡旋提取-电感耦合等离子体发射光谱(ICP-OES)法测定酸性和中性土壤中交换性盐基总量

传统的土壤交换性盐基总量检测方法前处理过程复杂，检测时间长，建立涡旋提取-电感耦合等离子体发射光谱(ICP-OES)法，大大提高了检测效率。采用涡旋提取中性和酸性土壤中交换性盐基总量，结合电感耦合等离子发射光谱仪（ICP-OES）同时测定土壤提取液中交换性盐基总量钙镁钠钾含量。通过考察土液比，涡旋时间，涡旋转速以及方法的精密度和准确度。结果表明，最佳涡旋条件为土液比为1:50，涡旋时间为20 min，涡旋速度为1500 r/min。利用ICP-OES测定国家标准物质RMH-A275、RMH-A274和GBW07458a（ ASA-7a）土壤提取液中交换性盐基总量钙镁钠钾含量，各元素测定结果均在标准值范围内，相对标准偏差均小于2 %，交换性钙镁钠钾的方法检出限分别为0.048 cmol/kg、0.035 cmol/kg、0.038cmol/kg和0.072 cmol/kg。应用该方法检测20份耕地实际土壤样品，与国标法相比，交换性盐基总量钙镁钠钾的测定值相对误差均小于2 %，满足土壤样品分析检测的要求。该方法操作简便、试剂用量少，准确度和精密度好，适用于大批量生态地球化学评价土壤样品中交换性盐基总量钙镁钾钠的测定。

Determination of Total Exchangeable Base in Acidic and Neutral Soils by Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES) with Vortex Extraction

The traditional total detection method of soil exchangeable salt base has a complex pretreatment process and a long detection time. The establishment of the vortex extraction-inductively coupled plasma emission spectrum (ICP-OES) method greatly improves the detection efficiency.The total amount of exchangeable base in neutral and acidic soil was extracted by vortex, the total amount of calcium, magnesium, sodium and potassium in soil extract was determined simultaneously by inductively coupled plasma emission spectrometer (ICP-OES).The soil-liquid ratio, vortex time, vortex speed, precision and accuracy have been studied. The results show that the optimal vortex condition was a soil-liquid ratio of 1:50, vortex time of 20 min and vortex velocity of 1500 r/min.This article utilizes ICP-OES to determine the totalt amount of exchangeable bases (calcium, magnesium, sodium, and potassium) in the soil extract solutions of national standard reference materials RMH-A275, RMH-A274 and GBW07458a (ASA-7a). The results show that each element measurement were within the standard range and relative standard deviations of less than 2%. The detection limits for exchangeable calcium, magnesium, sodium and potassium were 0.048 cmol/kg, 0.035 cmol/kg, 0.038 cmol/kg and 0.072 cmol/kg respectively. This method was applied to test 20 actual soil samples from cultivated land which was Compared with the national standard method , the relative errors of the determinations of exchangeable cations (calcium, magnesium, sodium, and potassium) in the total amount were all less than 2% and meeting the requirements of soil sample analysis and testing. This method is easy to operate, little amount of reagent and good accuracy and precision which is suitable for the determination of exchangeable bases (calcium, magnesium, sodium, and potassium) in soil samples for large-scale ecological geochemical evaluation.