A simple, rapid and sensitive method based on in situ derivatization combined with magnetic ionic liquid (MIL)-dispersive liquid-liquid microextraction (DLLME) was developed for the determination of biogenic amines (BAs). Six BAs (tryptamine, phenylethylamine, histamine, tyramine, spermidine, and spermine) were in situ derivatized with dansyl chloride (DNS-Cl), extracted by MIL-DLLME, and then chromatographed by high-performance liquid chromatography with ultraviolet detection (HPLC-UV). This MIL trihexyltetradecylphosphonium tetrachlorocobalt (II) [P6,6,6,14+]2[CoCl42-] was explored as the extraction solvent with the advantages of magnetic susceptibility, hydrophobicity and mobile phase compatibility. Furthermore, the MIL was designed to reduce hydrolysis in aqueous solvent as well as decrease absorbance when submitted to HPLC. In order to obtain optimized extraction efficiency, the MIL mass, the volume of derivatizing agent, the type and volume of disperser, the derivatizing and extraction time, and pH of sample solution were investigated. The proposed method was successfully applied for the analysis of wine and fish samples, and the recoveries of analytes achieved were in the range of 93.2-103.1% and 94.5-102.3%, respectively. The limits of detection/quantification for wine and fish samples were in the range of 1.3-3.9/4.1-9.9 μg/L and 1.2-3.8/3.9-9.6 μg/kg, respectively. Additionally, good reproducibility with relative standard deviations lower than 4.9% (n = 5) was obtained for the analysis of wine and fish samples. The in situ DNS-Cl derivatization and MIL-DLLME method was an efficient, rapid, environmental friendly microextraction approach for the determination of BAs in foodstuffs.
Keywords: Biogenic amines; Dispersive liquid-liquid microextraction; High-performance liquid chromatography; In situ derivatization; Magnetic ionic liquid.
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