The use of iron loaded silica to selectively preconcentrate, by a chelating effect, catechol and its derivatives has been investigated. Parameters which can influence the breakthrough volume, such as minimum saturation concentration, variation of pH, ionic strength and flow rate of the preconcentrated phase are described.
The coupling of this method with an ion-pairing chromatographic separation is demonstrated, several eluting solutions have been investigated. The influence of elution times, the linearity, the limit of detection and the recovery of the system are studied.
This method has been applied to the quantitative determination of catecholamines in urine samples using 1,2-dihydroxybenzylamine as an internal standard.
Key Words Column liquid chromatography - Catecholamines in urine - Liquid-solid extraction - Metal-loaded silica