Determination of Free Fluoride in Toothpaste by Ion Chromatography / 环境与健康杂志

ABSTRACT

To determine fluoride in toothpaste samples by ion chromatography,the solution of NaHCO3 and the solution of Na2B4O7-NaOH were selected as eluents respectively to optimize chromatographic detection conditions. Either the 0. 45～1.0 mmol/L NaHCO3 solution or the 5.0～20. 0 mmol/L NaB4O7-1. 0～2.0 mmol/L NaOH solution as eluents could effectively separate the chromatographic peak of fluoride in toothpaste samples from acetate and formate and accurately quantify the contents of fluoride in toothpaste samples. The recovery rates,precision(relative standard deviation) and detection limit were 92.5％～100. 2％ ,＜0. 6％ and 0. 208 mg/kg respectively. The data obtained by ion chromatography using NaHCO3 solution as eluent more approached to that by selective-fluoride-ion-electrode.