COMPARISON OF TURBULENT-FLOW CHROMATOGRAPHY AND CONVENTIONAL REVERSED-PHASE LIQUID CHROMATOGRAPHY FOR THE ON-LINE PRECONCENTRATION OF ANTI-INFECTIVES IN WASTEWATERS

摘要

Our study showed that TCC load columns for on-line preconcentration are an interesting alternative over traditional HPLC columns for the analysis of environmental waters, especially when large volumes (>1 mL) of dirty samples are used. TFC columns can be charged at higher sample flow rates than HPLC columns without causing excessive backpressures. This allows to reduce the effect of increased dead volume when using lager sample loops. Also they are less affected by column-fouling caused by particulate matter. Study of matrix effects for the three columns showed than in spite of the wash step performed before desorption with the LC gradient, signal distortion caused by matrix components is still important and that in the absence of the appropriate isotopically-labeled internal standards accurate quantitation by internal calibration is not possible. Therefore, quantitation by the standard additions method is the best solution to compensate for matrix effects.