Densitometric TLC Analysis of Histamine in Fish and Fishery Products

A simple and rapid densitometric thin-layer chromatographic method, suitable for monitoring the histamine content of fish and fishery products according to Commission Regulation (EC) No. 2073/2005, has been introduced. The sample was homogenized with methanol, heated in a water bath, and centrifuged. The sample extracts and standard solutions of histamine were applied to silica gel 60 HPTLC plates and developed by ascending chromatography with acetone-ammonia 95:5 (v/v) as mobile phase. Histamine was visualized with ninhydrin. The intensity of the colored spots was measured by densitometry at 410 rim. Successful separation of histamine from other biogenic amines and other ninhydrin-positive components in methanolic fish extracts was achieved. The relative standard deviation of repeatability was between 4.7 and 9.8% in the concentration range from 50 to 300 mg kg(-1) and 14% for within-laboratory reproducibility at 100 mg histamine kg(-1). Good correlation was achieved by use of an external standard calibration plot in the same concentration range. Accuracy of the method was checked by participation in the proficiency-testing programs organized by FAPAS, with satisfactory results.