[Determination of histamine in fish and fish products by tandem solid-phase extraction]

[Determination of Nonvolatile Amines in Foods by HPLC Following Fluorescamine Derivatization]

A method was developed for the determination of nonvolatile amines, such as histamine, tyramine, putrescine, and cadaverine, in foods. These nonvolatile amines were extracted from a sample with 5% trichloroacetic acid, and the extract was purified using an InertSep MC-1 cartridge column. The four amines were derivatized with fluorescamine, determined by HPLC with a fluorescence detector, and confirmed by LC-MS/MS. The average recoveries (n=5) and the relative standard deviations from 11 foods (pacific saury, dried mackerel, canned mackerel in brine, canned tuna in oil, fish sauce, surimi, rice-koji miso, soy sauce, gouda cheese, red wine, and beer) spiked at 100 mg/kg were 81-100% and 0.4-3.1%, respectively.

[Determination of Histamine by a Rapid Fluorescamine-UPLC Method]

We have developed a rapid analysis method for determination of histamine using ultra-performance liquid chromatography and fluorescamine derivatization. Histamine was extracted from foods with trichloroacetic acid after homogenization. The supernatant obtained by centrifugation was filtered and derivatized without solid-phase extraction. The mobile phase was 10 mM phosphate-acetonitrile (75 : 25) without ion-pairing. Recovery tests of histamine from fishes, seasoning and fish products gave acceptable recovery (95.8-117.7%). This method should be useful for rapid evaluation of food poisoning outbreaks.

Determination of Nonvolatile Amines in Foods by Improved Dansyl Derivatization Reaction

An analytical method for the determination of nonvolatile amines (putrescine, cadaverine, histamine, tyramine, and spermidine) in foods was developed, using an improved dansyl derivatization technique. The five amines were extracted from food with 1% trichloroacetic acid. Three milliliter of extract was applied to a polymer-based strong cation exchange resin mini-column, which was washed with 5 mL of water, and eluted with 5 mL of 1 mol/L potassium carbonate solution. The eluate was dansylated, then 5 mL of toluene was added with shaking. The toluene layer was evaporated. The residue was taken up in 1 mL of acetonitrile and shaken with 1 mL of 5% proline in 1 mol/L potassium carbonate solution. The upper acetonitrile layer was collected, filtered, and subjected to HPLC. The limits of quantitation for putrescine and cadaverine in the samples were both 0.2 μg/g; those of spermidine, tyramine, and histamine were 0.8, 2.0, and 5.0 μg/g, respectively. The average recoveries of the five amines from nine foods exceeded 80%.