Development of an Isotope Dilution UHPLC–QqQ-MS/MS-Based Method for Simultaneous Determination of Typical Advanced Glycation End Products and Acrylamide in Baked and Fried Foods

In this work, a stable isotope dilution ultrahigh-performance liquid chromatography triple quadrupole tandem mass spectrometry (UHPLC–QqQ-MS/MS) method was developed and validated for simultaneous determination of Nε-(carboxymethyl)lysine (CML), Nε-(carboxyethyl)lysine (CEL), and acrylamide (AA) in baked and fried foods. Ground food samples were extracted with acetone followed by two parallel assays. In assay A, a cleanup procedure based on dispersive solid-phase extraction was conducted for AA, free CML, and CEL analysis using the supernatant. In assay B, a multistep process including reduction, protein precipitation, acid hydrolysis, and solid-phase extraction was conducted for bound CML and CEL analysis using precipitation. The developed method was validated in terms of linearity, sensitivity (limit of detection, LOD; limit of quantitation, LOQ), accuracy, and precision. The results showed that the method had a wide linear range (0.25–500 ng/mL for CML and CEL, 0.5–500 ng/mL for AA), low LOD and LOQ (0.47–0.94 and 1.52–1.91 μg/kg, respectively), and good linearity (R2 > 0.999). The recovery test on baby biscuit and French fries samples showed the recovery rates of 90.2–108.3% for CML, 89.0–106.1% for CEL, and 94.5–112.3% for AA with satisfactory precision (relative standard deviation (RSD) < 10%). Finally, the developed method was successfully applied to 11 baked and fried food samples, and total CML, CEL, and AA contents varied in the ranges of 4.07–35.88 mg/kg, 1.99–14.49 mg/kg, and 5.56–506.64 μg/kg, respectively. Therefore, the isotope dilution UHPLC–QqQ-MS/MS method developed herein is promising for routine analysis of CML, CEL, and AA in baked and fried foods.