Acrylamide or 2-propenamide (AAM), a water-soluble toxic contaminant, has recently caused health concern after it was found in food products made by high-temperature cooking. Due to its weak UV absorption and electrochemically inactive state, common analytical methods do not have sufficient sensitivity to meet the World Health Organization requirement. A LIF detection method mediated by water-soluble CdTe quantum dots capped with mercaptopropyl acid (MPA) is thus developed for AAM quantitation. The optimized conditions are as follows: 30 mmol/L SDS, 0.1 mmol/L quantum dot, and 40 mmol/L phosphate buffer solution at pH 8.0 under 18 kV run voltage with LIF detection at 473 nm excitation and 568 nm fluorescence. The linear quantitation range for AAM was found to vary from 1.0 to 100 mg/kg and a detection limit (S/N=2) at 0.1 mg/kg, showing sufficient sensitivity to meet the maximum AAM specified by the Joint Food and Agriculture Organization/World Health Organization Expert Committee for potato crisps. Recoveries for potato crisps sample spiked with 10, 20, and 100 mg/kg AAM were found to vary between 90 and 95% with RSD <5.7% (n=3).
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