Automatic headspace sampling for determination of XXXX residues in cereals.

@entity8653 @entity9105 @entity8441 @entity3505 @entity579
The possibility was investigated to apply a commercially available automatic head-space sampler in trace analysis of @entity8441 ( @entity8653 , @entity8441 ), in cereals. Samples of @entity579 and @entity3505 flour were thermostatted in closed vials at 70 degrees C for 30 min. 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 @entity9105 ). The relative standard deviation of the method was 3.4% for @entity579 and 4.5% for @entity3505 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.
