Determination of the concentrations of organic acid in apple vinegar by high performance liquid chromatography with two coupled columns

A sensitive method for the determination of six organic acids in apple vinegar by high-performance liquid chromatographic with two coupled columns was established. After diluted with distilled water,the samples were analyzed by two coupled C18columns( 4.6 mm × 250 mm × 5 μm). The mobile phase for isocratic elution was 0.01 mol / L( NH4)2HPO4buffer( p H2.7),the flow a rate was 1.0 m L / min,and the detection wavelength was 210 nm.The correlation coefficient of six organic acids was greater than 0.999 in linear range. The precision of the six organic acids were less than 5.0%.The recoveries were in the range of 92.82% ~102.12%,and the limit of detection were in the range of 0.1 ~ 0.7 mg / L. The method was rapid,accurate and reliable,and can be used to determine organic acid in apple vinegar.