Multisyringe flow injection analysis coupled to capillary electrophoresis (MSFIA-CE) as a novel analytical tool applied to the pre-concentration, separation and determination of nitrophenols

For the first time, a multisyringe flow injection analysis capillary electrophoresis system is described. The potential of the hyphenation for sample treatment including analyte pre-concentration is demonstrated by its successful application to the determination of mono-nitrophenols (NPs) in different water samples. The analytical system was used to automate in-line sample acidification, analyte pre-concentration, elution, hydrodynamic injection, electrophoretic separation, and detection as well as the maintenance and re-conditioning of the solid-phase extraction (SPE) column and the separation capillary. A pre-concentration factor of better than 115 and detection down to 0.11 micromol L(-1) were achieved. Detection was carried out at visible wavelength using a blue LED as a low baseline-noise light source. High repeatability was obtained each for migration times and for peak heights with relative standard deviations typically below 2.5 and 6% including the pre-concentration procedure, respectively. Three injections per hour were achieved by running in parallel the pre-concentrating and the electrophoretic separation procedures. Instrumental control and data registration and evaluation were carried out with the software package AutoAnalysis, allowing autonomous operation of the analytical system.