返滴定法测定白矾散中白矾的含量

Determination of Alum in Baifan Powder by Residual Titration

关键词:  白矾散  白矾  返滴定  含量测定

Key words:  Baifan Powder  Alum  Residual Titration  Determination

摘要:

建立白矾散中白矾含量测定的方法。样品600 ℃灰化2 h后,加稀盐酸溶解,加过量EDTA-2Na配位Al3+,以二甲酚橙为指示剂,用锌滴定液滴定剩余的EDTA-2Na ,从而计算出白矾的含量。经方法学考察,本方法符合含量测定要求,平均回收率为98.6%,RSD为0.7%。所建立的测定方法结果可靠稳定性、重现性好,可用于白矾散的质量控制。

Abstract:

To establish a quantitative method for alum in baifan power. The sample was dissolved by dilute HCl after it was ashed in 600 ℃ for 2 h. Al3+and EDTA-2Na formed a complex. Using xylene orange as an indicator, excess amount EDTA-2Na was titrated by zinc titration solution. The content of alum can be calculated. Through the study methodology, approach was consistent with determination requirements. The average recovery rate was 98.6% (RSD=0.7%). The method was reliable and stable, with a good reproducibility, which can be applied in quality control of baifan power.