以DTPA为浸提液用原子吸收法测定土壤中有效Zn、Mn、Cu、Fe的方法,在国内外已广泛应用.我们在研究黄土区土壤中微量元素状况及其施肥效果时,使用了这种方法.为检验此法在本区是否适用,还作了回收试验和精密度测定,并就该法的分析条件作了若干对比.DTPA(二乙三胺五乙酸)是一种螯合剂,它与土壤溶液中游离的金属离子起作用,形成可溶性络合物.于是溶液中游离金属离子活性就降低,附着在土粒表面的养料就释放.土壤溶液中累积的被螯合金属 The method of determining the effective Zn, Mn, Cu, Fe in soil by DAS with the method of atomic absorption spectrometry has been widely used at home and abroad. We used this method to study the status of trace elements in soils and their fertilization effect in loess area In order to test the applicability of this method in this area, a recovery test and a precision determination were also made and some comparisons were made on the analysis conditions of the method.DTPA (diethylenetriaminepentaacetic acid) is a chelating agent, It works with the free metal ions in the soil solution to form a soluble complex, whereupon the free metal ion activity in the solution is reduced and the nutrients attached to the soil particles are released.The chelated metal accumulated in the soil solution