Abstract:

A method for simultaneous determination of 26 organic acids and anions in fruit juice by ion chromatography (IC) with suppressed conductivity detection using gradient elution was established. The effects of selection of columns, flow rates, column temperatures, pH values of solution, and eluent concentrations were studied, and then the suitable gradient elution conditions were found for the determination. The testing results of the 26 components in fruit juice were accurate under the conditions that the flow rate was 1.00 mL/min, column temperature was 30℃ and pH values of the solution were in the range of 5.5-6.8. As a result, the linear relationships of the 26 components were good in the range of 0.02-10.0 mg/L and the correlation coefficients (r) were greater than 0.995, the limits of detection (S/N=3) of the 26 components were in the range of 0.17-52.0 μg/L. In the added levels of 0.20-2.00 mg/L, the recoveries of the 26 components in fruit juice ranged from 85.58% to 108.86%, and the relative standard deviations (RSDs) were in the range of 0.15%-7.65% (n=6). The method is simple, quick, sensitive and accurate, and it is absolutely suitable for the trace analysis and determination of the 26 organic acids and anions in fruit juice.

Key words: anions, fruit juice, gradient elution, ion chromatography (IC), organic acids, suppressed conductivity detection