Resolution of folpet, procymidone and triazophos in high-performance liquid chromatography diode array detection by using partial least squares calibration to cross-sections of spectrochromatograms

Multi-wavelength detectors offer improved detection capabilities for liquid chromatographic methods, but require improvements in data analysis methodology to utilize all the available information. In this work, sections through the data matrix are carried out in order to obtain the highest sensitivity of the overlapping peaks produced on a HPLC-diode array detection multi-residue method when a new analyte has to be monitored. After three multivariate calibration methods, partial least squares (PLS-1 and PLS-2) and principal component regression, full spectrum calibration methods were applied to the simultaneous determination of the three pesticides, folpet, procymidone and triazophos. Hence, we resolved the interference that produces procymidone on the determination of folpet and triazophos pesticides with the maximum sensitivity for these pesticides. The approaches were applied satisfactorily to the determination of these pesticides in groundwaters at mu g l(-1) levels, after solid-phase extraction with C-18 cartridges. (C) 1997 Elsevier Science B.V.