Example of Analysis of Chlorine-Based Agricultural Chemicals in Cabbage
Example of Analysis of Chlorine-Based Agricultural Chemicals in Cabbage by the Backflush System
Residual agricultural chemicals in farm produce are potentially harmful to the human body. For this reason, residual criteria values are laid down by the type of crop and component in accordance with the regulations of each country. In food analysis, sample blanks contain lots of components, which tend to increase the time required for analysis. This analysis time, however, can be considerably shortened by performing backflush.
The following introduces an example where backflush analysis helps reduce the analysis time to less than half the regular time.
Chromatograms of cabbage extract and sample made by adding eight chlorine-based agricultural chemical standard samples to cabbage extract
(analysis by GC-ECD)
(α-BHC, β-BHC,γ-BHC,δ-BHC, P.P'-DDE, O,P'-DDT, P,P'-DDD, P,P'-DDT, 0.1 µg/mL each)
In a regular analysis, it takes 32 minutes to flush high boiling point components contained in cabbage. For example, when the component to be measured is BHC, set the backflush to 12 minutes after elution of BHC. With backflush analysis, however, analysis ends in 15 minutes, which means that the analysis time is reduced to less than half that by a regular analysis.
After this, a blank run was performed. You can see from the chromatogram that there are no residual blank components in the column.
The chromatogram below shows the result of conducting backflush analysis repeatedly for five times. Analysis has been performed with high reproducibility. You can also see from these results that there are no residual blank components from the cabbage in the column.
As shown above, with backflush analysis, not only can the analysis time be shortened, but no blank components are left in the column, which prevents both deterioration of the column and shift in the retention time.