Determination of two protein-bound advanced glycation end-products in bread by ultra-high performance liquid chromatography-tandem mass spectrometry based on protein precipitation

ObjectiveTo establish an ultra-high performance liquid chromatography-tandem mass spectrometry method for the detection of two typical advanced glycation end products （AGEs） in bread.MethodsProtein-bound carboxymethyl lysine （CML） and carboxyethyl lysine （CEL） were used as the detection objects. Bread sample was subjected to reduction incubation， protein precipitation， addition of isotope internal standard， acid hydrolysis， nitrogen blowing， reconstitution with nonafluorovaleric acid aqueous solution， and then underwent multi-reaction monitoring to quantitative analysis.ResultsThe detection limit and quantification limit of the method were 4.5 ng/g and 20 ng/g for CML， and 0.5 ng/g and 2 ng/g for CEL. The spike recovery rates of CML and CEL were 89.62%-95.65% and 86.38%-97.17%. The linear range were 2.5-800 ng/mL and 0.25-80 ng/mL， and the coefficients of determination were both above 0.999.ConclusionThe method was accurate and sensitive， and could meet the detection requirements of AGEs in bread.