自动分析仪测定土壤全磷的方法探讨

对AA3型连续流动分析仪测定土壤全磷的方法进行了试验研究.结果表明,通过调整试剂中的硫酸量使显色酸度在反应的适宜范围,该仪器能准确测定土壤样品中的全磷,与传统比色法的测定结果无显著差异,在线性区间,标准曲线r值可达到0.999以上,加标回收率为97.9%～102.1%,待测溶液最低检出限为0.012 mg/L.

Determination of soil total phosphorus by autoanalyzer

Determination method of soil total phosphorus by AA3 Continuous Flow Analytical System was investigated. The results showed that through sucking certain concentration sulfuric acid to the machine with another pump, instead of directly adding sulfuric acid to ammonium molybdate in order to moderate the pH of reaction solution, AA3 CFA can be used to assay soil total phosphorus accurately, and avoid the blue reaction after adding a little of sulfuric acid to the ammonium molybdate. The result of this method was not significantly different from the traditional colorimetry. In the linear area, the correlation efficiency for the standard curve was as high as over 0. 999, the recovery percentage of standard sample was 97.9 % - 102.1%, and the detection limit of the sample was 0. 012 mg/L.