Gas chromatographic method for putrescine and cadaverine in shrimp.

A gas-liquid chromatographic method developed for the determination of putrescine and cadaverine in fishery products was modified for application to the determination of diamines in shrimp. Addition of potassium chloride and hydrochloric acid to the methanol-water extraction solvent resulted in increased recovery of the diamines and minimized gel formation. The recovery of putrescine increased on average from 64 to 98%, and the recovery of cadaverine increased from 85 to 93%. The chromatographic separation of the derivatized diamines was significantly improved with a change from an OV-225 column (cyanopropyl methyl phenyl methyl silicone) to a more polar HP-Innowax column (crosslinked polyethylene glycol). Background levels of putrescine and cadaverine in known high-quality shrimp ranged from 0 to 0.7 ppm. Shrimp that failed sensory examination generally contained putrescine at levels >4.8 ppm and cadaverine at levels >1.3 ppm.