Liquid chromatographic determination of the fungicide XXXX in surface water, using on-line preconcentration.

@entity36096 @entity1626 @entity1044
A new method for on-line sample preparation of surface water extracts for the reversed phase HPLC analysis of the fungicide @entity36096 at the ppb level is presented. Water samples are extracted with @entity1044 and after concentration and evaporation to dryness, taken up in a mixture of @entity1626 /water. 2-Ml aliquots are injected onto a small precolumn, which is subsequently flushed with 20% @entity1626 in water as a clean-up step. The precolumn is switched on-line with the analytical column, and, using 47.5% @entity1626 in water as the eluent, the concentrated zone of @entity36096 is desorbed and transported to the analytical column. Detection takes place with UV at 229 nm. The resulting chromatograms are free of interferences. The detection limit of the method in 0.02 ppb. Good reproducibility and linear calibration curves are obtained. The results of the method are in agreement with those of capillary GC analysis with cold-on-column injection. The advantage of the method compared to GC is the lower susceptibility to errors due to the presence of interferences.
