碱熔-钼锑抗分光光度法测定土壤磷指示剂的改良  

Improvement of Indicator for Determination of Total Phosphorus in Soil by Alkali Fusion-Mo-Sb Anti Spectro-photometric Method

作　　者：庞艳秋 张琴琴 PANG Yan-qiu;ZHANG Qin-qin(Geoanalysis Center,Regional Geological Surveying Team,BGEEMRSP,Chengdu 610213)

机构地区：[1]四川省地质矿产勘查开发局区域地质调查队,成都610213

出　　处：《四川地质学报》2021年第S01期167-168,共2页Acta Geologica Sichuan

摘　　要：由于碱熔-钼锑抗分光光度法测定土壤中的总磷方法中,溶液的酸度决定磷钼蓝的形成及稳定,因此pH指示剂很重要。但是2,4-二硝基酚指示剂几乎不溶于冷水,经加热溶解冷却后有固体颗粒析出,影响pH显色判断,并且它又属易制爆化合物,其储存、使用的程序繁琐,给日常分析测试工作增加负担和难度。本文研究溴百里酚蓝做指示剂,使用程序便捷,颜色变化对比鲜明,易判断,不影响分析结果。pH indicator is of great importance to the method for determination of total phosphorus in soil by alkali fusion–Mo-Sb anti spectro-photometric method in view of the formation and stability of phosphomolybdate blue determined by the acidity of solution.But the 2,4-dinitrophenol indicator is almost insoluble in cold water and precipitates out solid particles after heating,dissolving and cooling which affects pH judgment.The storage and use procedure of the 2,4-dinitrophenol indicator as an explosive compound are very tedious.This study uses bromothymol blue as an indicator which is characterized by easy to use,color changes with a sharp contrast and doesn’t affect the analysis.

关 键 词：指示剂 溴百里酚蓝 分光光度法 

分 类 号：X53[环境科学与工程—环境工程]