Automatic Headspace Sampling for Determination of Ethylene Dibromide Residues in Cereals |
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Authors: | L A Pranoto-soetardhi M A H Rijk N De Kruijf R H De Vos |
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Institution: | TNO-CIVO Food Analysis Institute , P.O. Box 360, 3700 AJ, ZEIST, The Netherlands |
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Abstract: | Abstract The possibility was investigated to apply a commercially available automatic head-space sampler in trace analysis of ethylene dibromide (EDB, 1,2-dibromoethane), in cereals. Samples of rice and wheat flour were thermostatted in closed vials at 70ddot]C for 30min. The top gas was then automatically introduced into a gas chromatograph equipped with an electron capture detector. Quantitation was performed using external standards (untreated samples spiked with solutions of EDB in N,N′-dimethylacetamide). The relative standard deviation of the method was 3.4% for rice and 4.5% for wheat flour, at a residue level of 0.008 mg/kg. The detection limit was 0.001 mg/kg (the official EC residue tolerance is 0.01 mg/kg). Preliminary experiments with other fumigants were carried out as well. The headspace technique in question has the following advantages over other methods for determining EDB residues in cereals: 1. No sample pre-treatment like extraction, steam distillation, purge and trap etc.; 2. Automated sample handling; 3. “Clean” chromatograms. |
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Keywords: | Residues ethylene dibromide cereals automatic sampling head-space GLC |
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