ONLINE SOLID-PHASE EXTRACTION COUPLED TO SUPERCRITICAL-FLUID CHROMATOGRAPHY TO DETERMINE PHENOL AND NITROPHENOLS IN WATER

Determining of phenol and nitrophenols using solid-phase extraction on -line coupled to supercritical fluid chromatography (SFC) is studied. SFC quickly separated the compounds studied, in less than 6 min, and s olid-phase extraction was used to decrease the limits of detection. C- 18, PLRP-S and a highly cross-linked styrene-divinylbenzene copolymer in a 10x3 mm I.D. laboratory-packed precolumn were tested comparativel y as sorbents in the preconcentration step. Tetrabutylammonium bromide was used as ion-pair reagent in the extraction process to increase br eakthrough volumes, mainly for phenol. Performance of the method was c hecked with tap and river waters.