A simple method for determination of erythritol, maltitol, xylitol, and sorbitol in sugar-free chocolates by capillary electrophoresis with capacitively coupled contactless conductivity detection

In this work, a novel and simple analytical method using capillary electrophoresis (CE) with capacitively coupled contactless conductivity detection ((CD)-D-4) is proposed for the determination of the polyols erythritol, maltitol, xylitol, and sorbitol in sugar-free chocolate. CE separation of the polyols was achieved in less than 6 min, and it was mediated by the interaction between the polyols and the borate ions in the background electrolyte, forming negatively charged borate esters. The extraction of the polyols from the samples was simply obtained using ultra-pure water and ultrasonic energy. Linearity was assessed by calibration curves that showed R-2 varying from 0.9920 to 0.9976. The LOQs were 12.4, 15.9, 9.0, and 9.0 mu g/g for erythritol, maltitol, xylitol, and sorbitol, respectively. The accuracy of the method was evaluated by recovery tests, and the obtained recoveries varied from 70 to 116% with standard deviations ranging from 0.2 to 19%. The CE-(CD)-D-4 method was successfully applied for the determination of the studied polyols in commercial samples of sugar-free chocolate.