Determination of phosphorus in commercially available milk using ion chromatography with perchloric acid deproteinization

Suppressed ion chromatography with perchloric acid deproteinization was developed for the determination of phosphorus in commercially available milk. Although the perchloric acid deproteinization method is widely used in the medical field, it sees limited application in the food industry. Herein, the concentration of perchloric acid and hydrolysis conditions were examined, specifically regarding perchloric acid deproteinization, which was used as a deproteinization method in this study. The calibration curve constructed from the peak area of orthophosphoric acid (monohydrogen phosphate ion: HPO 4 2− ) was linear, with a correlation coefficient of 0.999. The relative standard deviation of the peak area of 50 mg/L of HPO 4 2− from six replicates was 0.35%. The detection and quantitative limits of HPO 4 2− , calculated from its signal-to-noise ratio were 0.033 mg/L and 0.100 mg/L, respectively. The proposed method was applied to the analysis of phosphorus in commercially available milk. Perchloric acid deproteinization has proved to be useful in the food industry. Graphical abstract