Thiol-ene Click Derivatization for the Determination of Acrylamide in Potato Products by Capillary Electrophoresis with Capacitively Coupled Contactless Conductivity Detection

The development of analytical methods for acrylamide formed during food processing is of great significance for food safety, but limited by its inherent characteristics, the analysis of acrylamide is a continuing challenge. In this study, an efficient derivatization strategy for acrylamide based on thiol-ene click reaction with cysteine as derivatization reagent was proposed, and the resulting derivative was then analyzed by capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-(CD)-D-4). After systematic investigation including catalyst dosage (0-20 mM), reaction temperature (30-90 degrees C) and time (1-60 min), and cysteine concentration (0.2-3.6 mM), acrylamide could be efficiently labeled by 2.0 mM cysteine at 70 degrees C for 10 min using 4 mM n-butylamine as catalyst. Application of 10 mM triethylamine as separation buffer, the labeled acrylamide was analyzed within 2.0 min, and the relative standard deviations of migration time and peak area were less than 0.84% and 5.6%, indicating good precision. The (CD)-D-4 signal of acrylamide derivative showed a good linear relationship with acrylamide concentration in the range of 7-200 mu M with the correlation coefficient of 0.9991. The limit of detection and limit of quantification were calculated to be 0.16 mu M and 0.52 mu M, respectively. Assisted further by the QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample pretreatment, the developed derivatization strategy and subsequent CE-(CD)-D-4 method were successfully applied for the determination of acrylamide in potato products.