Technical Abstract: The effect of interfering amino acids on the accurate quantitation of sugars in sugar industry samples, using ion chromatography with integrated pulsed amperometric detection (IC-IPAD), was investigated. Industrial sugar samples included beet syrup, juice and molasses samples. Using sugar and amino acid standard mixtures, and industrial sugar samples, proline was found to co-elute with fructose and serine with sucrose, and both co-elutions were "additive", which caused both fructose and sucrose to be overestimated. Conversely, the co-elution of arginine with myo-inositol, and glutamine with glucose had a marked "suppressive" effect on sugar quantitation and both myo-inositol and glucose were underestimated. Various methods were investigated for their efficiency to remove interfering amino acids, but not remove sugars: prefiltering of dilute samples through cation exchange syringe filters proved the most efficient method. Using sugar and amino acid standard mixtures, within experimental error, the cation exchange filter restored the mean concentrations of myo-inositol, glucose and sucrose to expected values, and standard deviations for all sugars were reduced markedly. Removal of interfering amino acids in a beet juice from a sweet water tank caused increases in mean concentrations for myo-inositol (+4.2%) and particularly for glucose (+62.5%), and a decrease for fructose (-7.3%).