CROSS-SECTIONS OF SPECTROCHROMATOGRAMS FOR THE RESOLUTION OF OVERLAPPING PEAKS IN DIODE-ARRAY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Multi-wavelength detectors offer improved detection capabilities for l iquid chromatographic methods, but require multivariate approaches to utilise all the available information. The photodiode-array detector i n high-performance liquid chromatography (HPLC) generates a three-dime nsional data matrix, which is conventionally presented as an isometric projection or a contour plot. In this work, a new graphical technique is described for improving the quantitative results obtained from HPL C, using the available spectrochromatographic information in both the time and wavelength domains. The technique consists of performing cros s-sections through the data matrix to obtain the maximum analytical in formation for each of the analytes. Hence, the resolution of overlappi ng peaks and the sensitivity in the determination are optimised. In or der to demonstrate the validity and simplicity of the approach, the me thod has been applied to the resolution of synthetic mixtures of iprod ione, procymidone and chlorothalonil. Also, the method has been satisf actorily applied to the simultaneous determination of the pesticides i n environmental groundwater samples. (C) 1998 Elsevier Science B.V. Al l rights reserved.