Abstract
Graphitized Carbon Black (GCB) extractive cartridges are evaluated for on-line coupling with a C8 analytical column to determine eleven carbamates and one carboximide pesticide from spiked deionized water at the 1.2 μg/L level. Several experiments were carried out to ascertain whether GCB saturation, pesticide degradation on the surface, existence of by-pass channels, mobility among the bulk cartridge, or strong retention on the surface interfere with the determination of pesticides.
Problems in on-line CGB elution are partially solved by modifying the acetonitrile/water gradient to contain a front of 100% acetonitrile for a few seconds. Eluting the same GCB cartridges off-line with dichloromethane/methanol gives recoveries higher than 77% for the selected pesticides.
ACKNOWLEDGMENTS
The authors wish to thank the Conselleria de Cultura, Educació i Ciència de la Generalitat Valenciana (GV97-AG-03-13) for the financial support of this project, and the University of Valencia for J. M. Soriano's grant.