石灰性、中性土壤有效磷测定中指示剂替代研究

Study on Indicator Substitution in Determination of Available Phosphorus in Calcareous Soil and Neutral Soil

有效磷是土壤的重要组成部分,对植物生长有着重要意义。在使用碳酸氢钠-钼锑抗比色法测定土壤中有效磷含量时,选取二硝基酚作为指示剂,但由于二硝基酚存在一定的风险性而且难购买,所以,替代二硝基酚指示剂的选取工作很重要。经过理论分析和实验对比验证,甲基橙可以作为二硝基酚的替代指示剂,可用于辽宁省石灰性、中性土壤有效磷含量的测定。

Available phosphorus is an important component of soil and has great significance for plant growth.Dinitrophenol was selected as an indicator when the sodium bicarbonate-molybdenum-antimony anti-colorimetric method was used to determine the content of available phosphorus in soil.However,because dinitrophenol was risky and difficult to buy,it was very important to select the alternative dinitrophenol indicator.In this paper,the indicator was selected and verified.Finally,it was found that methyl orange could replace dinitrophenol in calcareous neutral soil.