Evaluation of microwave irradiation for analysis of carbonyl sulfide, carbon disulfide, cyanogen, ethyl formate, methyl bromide, sulfuryl fluoride, propylene oxide, and phosphine in hay.
Fumigant residues in hay were "extracted" by microwave irradiation. Hay, in gastight glass flasks, was placed in a domestic microwave oven, and fumigants were released into the headspace by microwave irradiation. Power settings for maximum release of fumigants were determined for carbonyl sulfide (COS), carbon disulfide (CS(2)), cyanogen (C(2)N(2)), ethyl formate (EF), methyl bromide (CH(3)Br), sulfuryl fluoride (SF), propylene oxide (PPO), and phosphine (PH(3)). Recoveries of fortified samples were >91% for COS, CS(2), CH(3)Br, SF, PPO, and PH(3) and >76% for C(2)N(2) and EF. Completeness of extraction was assessed from the amount of fumigant retained by the microwaved hay. This amount was determined from further microwave irradiation and was always small (<5% of the amount obtained from the initial procedure). Limits of quantification were <0.1 mg/kg for COS, CS(2), C(2)N(2), EF, and PH(3) and <0.5 mg/kg for CH(3)Br, SF, and PPO. These low limits were essentially due to the absence of interference from solvents and no necessity to inject large-volume gas samples. The microwave method is rapid and solvent-free. However, care is required in selecting the appropriate power setting. The safety implications of heating sealed flasks in microwave ovens should be noted.
Ren
Yonglin
Y
CSIRO Entomology, GPO Box 1700, Canberra, ACT 2601, Australia. Yonglin.Ren@csiro.au
Mahon
Daphne
D
D000821:Animal Feed / Q000032:analysis*; D002246:Carbon Disulfide / Q000032:analysis; D004852:Epoxy Compounds / Q000032:analysis; D005514:Food Irradiation; D005563:Formic Acid Esters / Q000032:analysis; D005651:Fumigation; D006842:Hydrocarbons, Brominated / Q000032:analysis; D007306:Insecticides / Q000008:administration & dosage* / Q000032:analysis; D000455:Medicago sativa / Q000737:chemistry*; D008872:Microwaves; D009570:Nitriles / Q000032:analysis; D010720:Phosphines / Q000032:analysis; D013441:Sulfinic Acids / Q000032:analysis; D013461:Sulfur Oxides / Q000032:analysis
D004852:Epoxy Compounds; D005563:Formic Acid Esters; D006842:Hydrocarbons, Brominated; D007306:Insecticides; D009570:Nitriles; D010720:Phosphines; D013441:Sulfinic Acids; D013461:Sulfur Oxides; C510888:ethyl formate; C011206:cyanogen; C048899:sulfuryl fluoride; C010063:carbonyl sulfide; C005218:methyl bromide; C044646:phosphine; D002246:Carbon Disulfide; C009068:propylene oxide