CROSS-SECTIONS OF SPECTROCHROMATOGRAMS FOR THE RESOLUTION OF FOLPET, PROCYMIDONE AND TRIAZOPHOS PESTICIDES IN HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH DIODE-ARRAY DETECTION

The rapid-scanning photodiode array detector generates a considerable amount of data in HPLC, such as the three-dimensional (A, lambda, t) m atrix, but requires improvements in data analysis methodology to utili ze all the available information, In this paper, a graphical technique is used for improving the selectivity of HPLC analysis, using the ava ilable spectrochromatographic information in both the time and wavelen gth domains. The technique consists in performing cross-sections throu gh the data matrix to obtain selective analytical information for each of the analytes, In order to demonstrate the validity and simplicity of the method it has been applied in the simultaneous determination in mixtures of the three pesticides folpet, procymidone and triazophos. The procedure was applied with satisfactory results in the determinati on of these pesticides in groundwater at ppb levels after solid-phase extraction with C-18 cartridges.