高钛渣、金红石中磷的测定,采用正丁醇—氯仿萃取钼兰比色法。试样以碱熔融,水浸分离钛、铁等干扰元素,用硝酸调整滤液酸度,加钼酸铵生成磷钼杂多酸,可被正丁醇—氯仿萃取,然后用氯化亚锡反萃取、在水相使磷钼杂多酸还原为磷钼兰。该法稳定,易于掌握,干扰元素少,由于磷的富集,可提高灵敏度三倍以上,测定范围为0.1～0.001％的P. Determination of high titanium slag, rutile phosphorus, n-butanol - chloroform extraction molybdenum blue colorimetry. Sample melting with alkali, water immersion separation of titanium, iron and other interference elements, with nitric acid to adjust the filtrate acidity, ammonium molybdate generated phosphomolybdic heteropoly acid, can be n-butanol - chloroform extraction, and then stannous chloride back extraction , In the water phase so that molybdenum phosphomolybdate is reduced to phosphomolybdenum blue. The method is stable, easy to grasp, with fewer interfering elements. Due to the enrichment of phosphorus, the sensitivity can be increased more than three times, and the determination range is 0.1% to 0.001%.