Simultaneous Determination of Glycerol and Carbohydrates in Sweat by Capillary Electrophoresis with Amperometric Detection

Background: Glycerol, sucrose, lactose, glucose, and fructose are important biomarkers in human sweat because their contents can reflect physiological status and health conditions. It is of high importance to determine them in sweat for health monitoring, disease diagnosis, physical training, etc. Aim: The aim of this work is to develop a method based on capillary electrophoresis and amperometric detection for the simultaneous determination of glycerol and carbohydrates in sweat. Objective: A capillary electrophoretic method based on pipette-tip-based detection electrodes and micro-injectors was developed for the simultaneous determination of glycerol, sucrose, lactose, glucose, and fructose in sweat samples Method: Sweat samples diluted in the background electrolyte of 75 mM NaOH aqueous solution were electrokinetically introduced into a piece of separation capillary via pipette tip-based microinjectors. Glycerol, sucrose, lactose, glucose, and fructose were determined by capillary electrophoresis in combination with a pipette-tip-based copper electrode. Results: At a DC voltage of 12 kV, the capillary electrophoretic separation of the five analytes could be achieved in less than 11 min in a piece of 40 cm long fused silica capillary containing 75 mM NaOH aqueous solution. Linearity was observed between the currents and concentrations, with the limits of detection ranging from 0.21 to 0.72 µM at a detection potential of 0.65 V. Glycerol, sucrose, lactose, glucose, and fructose in sweat samples were positively identified and accurately measured. Conclusion: The method was successfully applied in the simultaneous determination of glycerol and carbohydrates in sweat samples with satisfactory assay results. It will find a wide range of applications in clinical diagnosis, health monitoring, and drug and food analysis.