离子选择性电极法测定牙膏中的氟含量

STUDY ON DETERMINATION OF TOTAL FLUORINE IN TOOTHPASTE BY ION SELECTIVE ELECTRODE METHOD

〔目的〕探讨TISAB溶液作为金属离子掩蔽剂和OH-离子的pH调节剂对氟离子选择电极测定牙膏氟含量的影响。〔方法〕进行不同条件、不同方法的对比实验。〔结果〕选用TISAB(I),用量控制在60￣80mL,适宜测定的pH值为6￣7,回收率为98.6%￣104.00%,RSD<2.7%。〔结论〕分析方法的准确度、重现性、线形关系、稳定性均能达到科研和生产的要求,操作简便,可推广用于化妆品中氟含量的测定。

This is to study the effect of TISAB as masking agent of metal ions and pH conditioning agent of [OH^-] ion to the determination of total fluorine in toothpaste by ion selective electrode method. Comparative tests were made under different conditions and methods. Taking an amount of 60～80mL TISAB（I）, with pH value of 6～7, the recoveries are 98.6%～104.00% and RSD〈2.7%. It shows that the method is simple and accurate with good reproductivity and stability and can be used in the determination of fluorine in cosmetics.