Sorption of propylene oxide by various commodities
Ali A. Isikber,a,*, Shlomo Navarrob, Simcha Finkelmanb, Miriam Rindnerb, Rafael Diasb
aDepartment of Plant Protection, Faculty of Agriculture, University of Kahramanmaras Sutcu Imam, Kahramanmaras 46060, Turkey
bDepartment of Stored Products, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet-Dagan 50250, Israel
Accepted 22 April 2004
Abstract: Sorption of propylene oxide (PPO) by various commodities was studied at different concentrations during a 4-h exposure at 30 °C. A gas chromatograph was used to determine sorption of PPO applied at concentrations of 24, 49, 82 and 112 mg/l by 170.01 kg of narcissus bulbs, wheat, corn and cocoa beans in 2.64-l fumigation chambers. Results showed that for corn and cocoa beans the decrease in concentration during the first hour, that ranged from 40% to 76% of the initial concentration applied, was much greater than that for narcissus bulbs and wheat, which ranged from 25% to 41% of the initial concentration applied. PPO was initially taken up faster by corn and cocoa beans than by narcissus bulbs and wheat. The average sorption rate for each commodity increased with increasing initial concentration. The average sorption rate of PPO by corn and cocoa beans ranged from 14.9 to 48.6 ((mg/kg)/h) which was higher at each concentration than sorption by narcissus bulbs and wheat. In spite of the relatively high rates of sorption, the PPO residues among wheat, corn and cocoa beans immediately following a 4-h fumigation were well below the 300 ppm tolerance. These data show that PPO rapidly desorbed from the commodities under fumigation at 30 °C and at ambient atmospheric pressure.
© 2004 Published by Elsevier Ltd.
Key words: Propylene oxide; Fumigation; Sorption; Narcissus bulbs; Corn; Wheat; Cocoa beans
