Determination of phosphates and polyphosphates using capillary isotachophoresis

Abstract

In this article, phosphate, di- and triphosphates are the analytes determined in commercially marketed samples with the aid of capillary isotachophoresis. After method development, the optimal electrolyte system comprised 10 mM HCl + β-alanine + 0.1% hydroxy-ethylcellulose (pH 3.6) as the leading electrolyte and 10 mM citric acid as the terminating electrolyte. The calibration / detection characteristics are as follows: linearity over the concentration range of 0–200 mg.l-1 P2O5, limit of detection ca. 0.3 mg.l-1 P2O5, limit of quantification of ca. 1 mg.l-1 P2O5. The time of analysis was from 15 to 30 minutes. Furthermore, relatively simple procedure, low operational costs, and sufficient sensitivity are further positive attributes of the method tested in analyses of selected real samples.