alpha-Dicarbonyl compounds (alpha-DCs), formed during food heating and storage, are crucial for assessing food safety and quality. However, the low concentration, high reactivity, and absence of chromophores of alpha-DCs make their detection challenging, often requiring complex derivatization and extraction. This study developed a one-pot method for alpha-DCs that combines derivatization and magnetic solid-phase extraction. By mixing the sample, 2,3-diaminonaphthalene, and Fe3O4/MWCNTs-OH in a vial, simultaneous derivatization and extraction are achieved. Derivatization converts alpha-DCs into hydrophobic products, facilitating their adsorption and enabling sensitive liquid chromatography-fluorescence detection. The introduction of the magnetic adsorbent allows phase separation to be easily achieved using an external magnet, simplifying and speeding up the process. The detection limits for six alpha-DCs (glyoxal, methylglyoxal, diacetyl, 2,3-pentanedione, D-glucosone, and 3-deoxyglucosone) were determined to be in the range of 0.4-3.5 nM. This rapid and convenient analytical approach was successfully applied to analyze alpha-DCs in juices, coffees, and tea beverages.