本工作研究了用邻苯三酚红—溴化十六烷基三甲铵作指示剂,在pH0.7—1.7螯合滴定铋。终点由紫红到黄十分敏锐。利用在弱酸性介质中,以磷酸铋形式沉淀磷酸根,间接测定磷,终点同样敏锐。经过实际样品考验,分析结果准确可靠,方法快速简便。 This work studied the use of pyrogallol red - cetyltrimethylammonium bromide as an indicator, chelated titration bismuth at pH0.7-1.7. End point from purple to yellow is very sharp. In weakly acidic media, phosphate is precipitated in the form of bismuth phosphate to indirectly determine phosphorus, and the endpoint is equally sharp. After the actual sample test, the analysis results are accurate and reliable, the method is quick and easy.