On-line dual-precolumn-based trace enrichment for the determination of polar and acidic microcontaminants in river water by liquid chromatography with diode-array UV and tandem mass spectrometric detection

Dual-pre-column-based trace enrichment combined on-line with liquid chromat ography-diode-array UV and tandem mass spectrometric detection was used to determine a wide polarity range of organic microcontaminants in river water . Various sorbents were studied for their extraction efficiency of (highly) polar and acidic compounds and their ability to selectively remove humic s ubstances, which are normally co-extracted and interfere in the UV detectio n of polar microcontaminants. An optimised on-line dual-pre-column set-up w ith PLRP-S in the first pre-column and Hysphere-1 in the second pre-column was used to study the analytical performance of the procedure. Tandem MS wa s used for confirmation purposes and to quantify the organic microcontamina nts in river water at the low-ng/l level. In addition, the influence of the type of sample (drinking and river water) on suppression of analyte respon ses in electrospray ionization MS was studied. (C) 2000 Elsevier Science BN . All rights reserved.