由于Fe~(3+)对二甲酚橙产生僵化,用以直接滴定铁受到限制。西山雅祥等认为:温度在50℃以上,醋酸存在时,pH在1.2—5.3范围内,以二甲酚橙为指示剂能够进行铁的滴定。我们改用5—15毫升2 M一氯醋酸作缓冲液,以5—12毫升NaF-H_3BO_3掩蔽铝、钛等干扰离子,以5—15毫升酒石酸消除Fe~(3+)对二甲酚橙的僵化作用,加热,在180—200毫升体积内 Due to Fe ~ (3 +) on the xylenol orange rigid, for direct titration of iron is limited. Xishan Yaxiang think: temperature above 50 ℃, the presence of acetic acid, the pH range of 1.2-5.3 to xylenol orange as an indicator of iron titration. We use 5-15 ml of 2 M monochloroacetic acid as a buffer, mask 5-12 ml of interference ions such as aluminum and titanium with 5-12 ml of NaF-H 3 BO 3, and eliminate 5% of tartaric acid with 5-15 ml of tartaric acid to eliminate xylenesol orange The inflexible effect of heating, within a volume of 180-200 ml