Determination of acrylamide in potato crisps by capillary electrophoresis with quantum dot‐mediated LIF detection

Abstract

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).

SDS-PAGE as a Tool for Hydrodynamic Diameter-Dependent Separation of Quantum Dots

“…Other reason may be their lower stability compared QDs with higher hydrodynamic diameter [35]. It was reported, that fluorescence of QDs was quenched due to the residues of polymerization agents ammonium persulfate [36], tetramethylethylenediamine [37] or acrylamide [38]. However, after polymerization of the gels, the free polymer subunits (acrylamide and bisacrylamide) and polymerization catalysers are present in trace concentration and their concentration is lowered by overnight storage of the gels [39].…”

Rapid methods for detecting acrylamide in thermally processed foods: A review

“…Two in-line preconcentration capillary zone electrophoresis (CZE) methods (field amplified sample injection (FASI) and stacking with sample matrix removal (LVSS)) have been evaluated for the analysis of AA in foodstuffs after being derivatized with 2-mercaptobenzoic acid, both of which showed similar sensitivity and precisions compared with chromatography-based methods (Bermudo, Núñez, Moyano, Puignou, & Galceran, 2007;Bermudo, Núñez, Puignou, & Galceran, 2006). A laser-induced fluorescence detection method mediated by CE with CdTe quantum dots (QDs) as amplifier was studied for the detection of AA in potato crisps with good recoveries (90e95%) and RSD (<5.7%) (Chen, Zhao & Fung, 2011).…”

Capillary Electrophoresis in Nanotechnologies versus Nanotechnologies in Capillary Electrophoresis

“…Optical detection in association with nanomaterials is mainly connected with quantum dots due to their application as a fluorescent labels in laser-induced fluorescence detection [62][63][64][65]. An indirect laser-induced fluorescence mode of detection by means of CdTe quantum dots has been demonstrated and therefore determination of small organic acids in food with detection limits in the range of tenths of mg/L was enabled [64].…”