Liquid chromatographic determination of the processing aid 4-hexylresorcinol in shrimp

A rapid, sensitive, liquid chromatographic (LC) method has been developed for determination of residuals of the processing aid, 4-hexylresorcinol, on shrimp meat. An aqueous homogenate of shrimp meat is extracted with ethyl acetate followed by precolumn preparation on a silica Sep-Pak cartridge. LC determination is preformed with a Nova-Pak C18 column, with UV detection at 214 nm. Sensitivity was 0.006 micrograms, and recovery from shrimp meat samples of known 4-hexylresorcinol addition was 94%. Shrimp treated with 4-hexylresorcinol under the recommended dip protocol had mean residuals of 1.18 ppm, with a standard deviation of 0.13 ppm.