土壤全磷测定中样品分解与比色方法的比较研究

Comparision of decomposition and colorimetry methods in determination of soil total phosphorus

比较H2SO4-HC lO4酸溶法和NaOH碱熔法两种样品消化方法以及钼锑抗比色法和钒钼黄比色法两种显色方法在测定土壤全磷中的效果。结果表明：对于中性和碱性土壤,酸溶法和碱熔法均可获得良好的分解效果;对于酸性土壤,碱熔法分解效果优于酸溶法。钼锑抗比色法测定待测液中磷,结果可靠,精密度与准确度高,酸溶法加标回收率为90.25%-99.16%,RSD为1.0%-2.7%。碱熔法加标回收率为90.24%-100.3%,RSD为1.1%-2.6%。钒钼黄比色法测定灵敏度低,结果偏低,不适合土壤全磷的分析。

Compared the effectiveness of H2SO4 - HClO4, NaOH decomposition methods, Mo - Sb and Van - Mo -yellow color/merry methods in the determination of soil total phosphorus. The results showed： in the neutral and alkaline soil, the acid digestion and the base digestion have the same satisfactory decomposition effects; in the acidic soil, the base digestion has better decomposition effect than the acid digestion. In the determination of phosphorus, Mo -Sb colorimetry method Can get the reliable results, the precision and accuracy is high. The recovery rate is 90.25% -99.16% and 90.24% -100.3% in the acid digestion and base digestion respectively. The RSD is 1.0% -2.7% and 1.1% -2.6% in the acid digestion and base digestion respectively. In the Van- Mo - yellow colorimetry method, the sensibility is low, the results are comparatively low, it is not suitable for the analysis of soil total phosphorus.