Determination of carbohydrates by hydrophilic interaction chromatography with pulsed amperometric detection using postcolumn pH adjustment

An HPLC method for the determination of carbohydrates using a postcolumn pH adjustment technique with lithium hydroxide solution followed by pulsed amperometric detection was developed. In conjunction with hydrophilic interaction chromatography, the technique was used to determine reducing sugars, non-reducing sugars and sugar alcohols. Detection limits from 0.7 to 2.7 ng with a signal-to-noise ratio of 3 were achieved. The relative standard deviation for peak was better than 2.7%. The postcolumn pH adjustment technique enabled gradient elution to be used.