Determination of histamine in tomatoes by capillary electrophoresis

An improved capillary electrophoresis assay for histamine in crude extracts was developed and used to determine histamine levels in a selection of tom ato fruits and pastes. Performance in terms of reproducibility and sensitiv ity was optimized by use of a high sensitivity detector flow cell, sodium h ydroxide rinses, and a voltage gradient. The method was linear down to 0.2 mu g/mL (signal-to-noise ratio = 4:1), which was below the endogenous level in all samples.