Determining Fluoride in Salts Using Capillary Zone Electrophoresis with Transient Isotachophoresois

抄録

We applied transient isotachophoresis （tITP） and capillary zone electrophoresis （CZE） with indirect UV detection to determine F⁻ in salts. The limit of detection （LOD, signal to noise ratio （S/N）＝3）） and limit of quantification （LOQ, S/N＝10） for F⁻ respectively reached 0.007 and 0.023 mg/L using a capillary with larger inner diameter （100 μm）. The respective values of the relative standard deviation （RSD, n＝4） of the migration time, peak area, and peak height for F⁻ were 0.35, 2.7, and 2.7 ％. Effects of coexisting components such as aluminum （Al³⁺）, iron （Fe³⁺）, magnesium （Mg²⁺）, and calcium （Ca²⁺） were examined. The adverse effects were resolved using metal complexation with diethylenetriamine pentaacetic acid （DTPA）. The proposed method was used to find F⁻ in salt samples. Results for CZE agreed with those obtained using conventional spectrophotometry.