Rapid analysis of propylene glycol in fatty foods.

Abstract

Rapid analysis of propylene glycol (PG) in fatty foods was developed by using kieselguhr column chromatography. 2-5 g of sample suspended in hot water (70-80°C) was applied to the Extrelut 20 column. After standing for 15 min, 70 ml of hexane was put on the column to remove fat. PG retained in the column was eluted with distilled water. 50 ml of aqueous eluate was collected. PG was quantitated by gas chromatography with trimetylene glycol as an intenal standard. Recoveries of PG added to margarines and mayonnaises were from 98% to 105%. Since proposed purification process is very rapid, many samples can be treated at the same time. Among commercial margarines (25 samples), shortenings (3 samples) and mayonnaises (3 samples), PG was detected in eight margarines (range 37-261 ppm).