Development of a SALLE-HPLC-FLD Analytical Method for the Simultaneous Determination of Ten Biogenic Amines in Cheese

In this work, a new methodology for the determination of biogenic amines in cheese is presented, which includes an innovative sample preparation approach based on salting-out assisted liquid-liquid extraction (SALLE). The method features a pre-extraction of the soluble biogenic amines with hydrochloric acid, a derivatization with dansyl chloride, the use of the salting-out effect, and the analysis of the derivatized biogenic amines using high-performance liquid chromatography with fluorescence detection. Several extraction parameters were studied and optimized, such as the HCl extraction time, concentration of the derivatization reagent and influence of the medium's pH, among others. For the considered biogenic amines, the developed method exhibits adequate limits of detection (0.015 to 1.77 mg L-1) and quantification (0.050 to 5.91 mg L-1) and average recoveries between 94 and 110%, with the highest determined amounts found for putrescine, dimethylamine and histamine. Furthermore, mass spectrometry studies identified and confirmed the presence of several biogenic amines in the samples. SALLE stands as a good alternative to existing methods, since it simplifies the sample preparation step, while improving the overall selectivity of the process. It may also be adopted for the determination of biogenic amines in different solid samples besides cheese, such as meat, fish or other food products.