An in situ benzoylation-dispersive liquid-liquid microextraction method based on solidification of floating organic droplets for determination of biogenic amines by liquid chromatography-ultraviolet analysis

A novel analytical method consisting of in situ derivatization combined with liquid phase microextraction followed by liquid chromatography-ultraviolet detection (LC-UV) was developed to determine the biogenic amines (BAs) of alcoholic beverages. Nine BAs (putrescine, cadaverine, 1,3-diaminopropane, tryptamine, phenylethylamine, spermidine, spermine, histamine, and tyramine) were derivatized in situ with benzoyl chloride, extracted by dispersive liquid-liquid microextraction based on solidification of floating organic droplets (DLLME-SFO), and then chromatographed by LC-UV. Factors influencing the derivatization and extraction efficiency were optimized, including the reaction buffer pH and concentration, amount of derivatization reagent, reaction time, types and volumes of extraction and dispersive solvents, and extraction time. Under the optimized conditions, the method was linear over 0.05-8.0μgmL^-1 with an r²≥0.992 and exhibited intra- and inter-day precision less than 8.8% and 11.5%, respectively. The limit of detection ranged between 0.005 and 0.01μgmL^-1. The developed method using a basic LC-UV system is sensitive, rapid, convenient, green, and cost-effective. Moreover, it is versatile and practical for the analysis of BAs, as demonstrated by the successful application in four different types of popular alcoholic beverages (white wine, red wine, rice wine, and beer).