title: Simultaneous determination of sulphide and sulphite by gas-phase molecular absorption spectrometry. Comparative study of different calculation methods.
abstract: A method for the simultaneous determination of sulphide and sulphite is described, which involves continuous H(2)S and SO(2) generation, preconcentration in a liquid nitrogen trap and measurement of the molecular absorption spectra of volatiles in the gas phase in 190-220 nm range. Under the recommended conditions (sample flow: 50 ml/min and concentrated sulphuric acid flow: 12 ml/min; generation time: 4 min) linear response ranges from 0.05 mug/ml for S(2-) and 0.20 mug/ml SO(2-)(3) are obtained with detection limits of 0.05 and 0.20 mug/ml respectively. Synthetic mixtures of the two components have been solved and a comparative study of different calculation methods has been made. In conclusion, multiwavelength methods offer better precision and accuracy.
authors.affiliation: Chemistry Department, Analytical Chemistry Section, University of La Rioja, Logroño-26001, Spain.
authors.forename: S C
authors.initials: SC
authors.lastname: Pinillos
authors.forename: I S
authors.initials: IS
authors.lastname: Vicente
authors.forename: J S
authors.initials: JS
authors.lastname: Asensio
authors.forename: J
authors.initials: J
authors.lastname: Galbán Bernal