METROLOGICAL CHARACTERISTICS AND COMPARISON OF ANALYTICAL METHODS FOR DETERMINATION OF CHROMIUM TRACES IN WATER SAMPLES
Jan Mocak,b Janusz
Dominik,c Helena Pereira,c
Bogusław Baś,a and Wiesław Knapd
a Department of Technology of Building Materials, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow, Poland
b Department of Analytical
c Institut F.-A. Forel, Université de Genève, CH-1290 Versoix,
dFaculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow,
* Corresponding author: E-mail: firstname.lastname@example.org; fax: +48 12 617 24 52
The analytical performance of the inductively coupled plasma mass spectrometry, absorption spectrophotometry and catalytic adsorptive stripping voltammetry has been compared for trace chromium determination in water samples. The following metrological characteristics were calculated: trueness, precision, linear analytical range, detection and quantification limits. The limit of detection, and the limit of quantification were calculated by the ULA method, which takes into consideration the uncertainties of the slope and the intercept of the calibration plot, designed especially for this purpose, as well as by traditional way as the 3- and 10-fold multiply of the blank standard deviation.
The possibility of the speciation study of both chromium oxidation states, Cr(VI) and Cr(III), has also been considered. The ICP MS procedures were applied to the determination of total chromium in river water samples. The catalytic adsorptive stripping voltammetric method with DTPA and nitrate is sufficiently sensitive for the determination of chromium traces at the level of 0.01 to 0.1 mg/L and suitable for the chromium speciation studies.
Key words: chromium, speciation, ICP MS, catalytic adsorptive stripping voltametry, adsorption spectrophotometry