Yoshinori Kikuchi

Gas chromatographic determination of nicotinamide in meats and meat products as 3-cyanopyridine

The determination of nicotinamide as 3-cyanopyridine after dehydration by heptafluorobutyric anhydride (HFB) was performed by gas-liquid chromatography (GLC) with flame ionization detection (GLC-FID) and a column of 5% OV-17 on Chromosorb W AW DMCS at 130 degrees C. Determination was possible with 3-100 micrograms of the dehydrated reaction mixture. The procedure for determining nicotinamide in various meats and meat products involves direct analysis by GLC-FID without a clean-up stage; the detection limit is 5 ppm and the recovery ranged from 93.4 to 104.6% (average 98.0%). Various possible interferents in the samples did not interfere in the production or determination of 3-cyanopyridine. The procedure is suitable for routine use. The dehydrated derivative of nicotinamide was confirmed as 3-cyanopyridine by combined gas chromatography-mass spectrometry and infrared spectrometry.

Residues of Clopidol (3, 5-Dichloro-2, 6-dimethyl-4-pyridinol) in Tissues and Eggs of Chickens

Residues of clopidol (3, 5-dichloro-2, 6-dimethyl-4-pyridinol) in chicken tissues and eggs were studied. Clopidol isolated from various tissues was determined by gas chromatography. Chickens of 10 weeks of age were given feed containing 250, 375 and 750ppm of clopidol for 10 days before laying eggs. The average contents of clopidol in the eggs were 6ppm, 10ppm and 19ppm, respectively. The concentration ratio (clopidol in whole egg/clopidol in feed ×100) of clopidol was found to be 2.64% on average, and clopidol in the egg disappeared within approximately one week.In other experiment, chickens of 4 weeks of age were given clopidol-containing feed (250, 375 and 750ppm) for 8 weeks. High concentrations of clopidol were found in the liver, blood and kidneys as compared with the breast, thigh muscle and fat. After cessation of medication, the clopidol concentration in each tissue fell below 0.1ppm within 3 days.