重铬酸钾用量对硫铬氧化法测定土壤有机碳的影响

硫铬氧化法是在恒温加热条件下(135±2℃),浓H2SO4介质中,用K2Cr2O7氧化土壤中的有机碳,通过分光光度法测定被还原的三价铬(Cr3+)含量来计算出土壤有机碳的含量。实验发现适当增加重铬酸钾的用量可提高分析方法的测定上限,更好适应土壤有机碳的测定。

The organic carbon present in soil is sulfochromic oxidized in a mixture of potassium dichromate solution（in excess）and sulfuric acid at temperature of 135 ℃（±2 ℃）,and the content of organic carbon in soil is measured through the determination of the content of reduced trivalent chromium by spectrophotometer.It is found that the superior limit of determination of organic carbon in soil can be increased by increasing the use level of potassium bichromate in the experiments,so it is more suitable to determinate the organic carbon in soil.