Determination of histamine in wines with an on-line pre-column flow derivatization system coupled to high performance liquid chromatography

A new rapid and sensitive high performance liquid chromatography ( HPLC) method for determining histamine in red wine samples, based on continuous flow derivatization with 1,2-naphthoquinone-4-sulfonate (NQS), is proposed. In this system, samples are derivatized on-line in a three-channel flow manifold for reagent, buffer and sample. The reaction takes place in a PTFE coil heated at 80 degrees C and with a residence time of 2.9 min. The reaction mixture is injected directly into the chromatographic system, where the histamine derivative is separated from other aminated compounds present in the wine matrix in less than ten minutes. The HPLC procedure involves a C-18 column, a binary gradient of 2% acetic acid-methanol as a mobile phase, and UV detection at 305 nm. Analytical parameters of the method are evaluated using red wine samples. The linear range is up to 66.7 mg L-1 ( r = 0.9999), the precision (RSD) is 3%, the detection limit is 0.22 mg L-1, and the average histamine recovery is 101.5% +/- 6.7%. Commercial red wines from different Spanish regions are analyzed with the proposed method.