Determination of carboxylic acids in water by gas chromatography using several detectors after flow preconcentration.
A novel analytical method is reported that combines continuous solid-phase extraction and gas chromatography for the determination of 22 carboxylic acids in water. The highly polar and hydrophilic analytes were preferentially sorbed on a mixture of LiChrolut EN-Supelclean ENVI-18 (1:1) sorbent column and eluted with methanol; this extraction process did not require derivatisation. The extract was analysed by gas chromatography coupled to a flame ionisation detector as well as a mass spectrometer with electron impact (EI) or positive chemical ionisation modes. The highest sensitivity was achieved when using MS-EI, with good linearity in calibration curves and low detection limits (2-40ngL(-1)) for 50mL of sample. The entire procedure from raw aqueous sample to a ready-to-inject methanol solution of the acids requires less than 15min. Another benefit of this method is the good accuracy (recoveries between 93 and 102%) and precision (relative standard deviation, 3.4-6.2%), which allows the determination of carboxylic acids in environmental water and in real chlorinated and ozonated drinking water.
Department of Analytical Chemistry, Campus of Rabanales, University of Córdoba, E-14071 Córdoba, Spain.
Beatriz
B
Jurado-Sánchez
Evaristo
E
Ballesteros
Mercedes
M
Gallego
D002264:Carboxylic Acids / Q000032:analysis*; D002849:Chromatography, Gas / Q000295:instrumentation / Q000379:methods*; D014867:Water / Q000032:analysis*
D002264:Carboxylic Acids; D014867:Water