离子色谱法测定含氟牙膏氟含量研究

目的:探讨离子色谱法测定含氟牙膏中氟化物的可行性和准确度。方法:比较离子色谱法与国家牙膏标准(GB8372-2001)氟离子电极法对含氟化钠、单氟磷酸钠和双氟3类牙膏氟含量测定的精密度和回收率,分析离子色谱法测定9支市售含氟牙膏的回收率情况以了解其抗干扰能力。结果:2种方法精密度之间经方差齐性检验没有统计学差异(P>0.05)。离子色谱法和氟离子电极法测定F-回收率的均值分别为1.00和0.99,差异无显著性(P>0.05);2种方法测定MFP2-回收率的均值分别为1.00和1.08,差异有显著性(P<0.05)。离子色谱法干扰实验结果显示个别数据偏差较大。结论:离子色谱法可用于含氟牙膏氟浓度测定,其在测定单氟磷酸钠牙膏的总氟含量准确度方面有一定优势,但实测中实验条件需进一步研究以提高抗干扰能力。

Determination of fluoride concentrations in toothpastes by using ion chromatography

Objective:To study the feasibility and precision of using ion chromatographic method to measure fluoride concentrations in toothpastes. Methods:Three kinds of fluoride toothpastes, containing NaF, NaMFP and NaF-NaMFP were measured of fluoride concentrations respectively by using ion chromatography (IC) and fluoride selective electrode (FSE) which is recommended by the Chinese Standard for Toothpaste(GB8372-2001). Precision and recovery rate of the two methods were evaluated. 9 tubes daily used fluoride toothpastes were measured by IC to evaluate the disturbance of other ions in the toothpaste. Results:There was no statistically significant difference in precision degree of the two methods (P>0.05). The recovery rate of F- measured by IC and by FSE had no significant difference (1.00 v.s. 0.99; P>0.05) but the recovery rate of MFP2- by IC and by FSE was statistically different (1.00 v.s. 1.08; P<0.05). One result of IC for NaF-NaMFP toothpaste showed very high recovery rate. Conclusion:IC method can be used to determine the fluoride concentrations in fluoride toothpastes. The result indicates that IC method had advantage in determination of total fluoride of NaMFP toothpastes. But the method needs further study to prevent the disturbance of other ions contained in the toothpaste.