ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

The Field Sampling Method for the Speciation of Chromium in Waters

V. Streško, J. Polakovičová, and A. Čelková

Geological Institute, Faculty of Natural Sciences, Comenius University, SK-842 15 Bratislava

E-mail: stresko@fns.uniba.sk

Abstract: Off-line ion-exchange chromatography followed by flame atomic absorption spectrometry (FAAS) determination was applied to the separation and preconcentration of Cr(III) and Cr(VI) in various types of waters. Reliability results with spiked solutions containing equimolar mixture of Cr(III) along with Cr(VI) were achieved with the anion-exchange resin Amberlite IRA-410 as well as cation exchanger Amberlite IR-120. With regard to the possible redox changes of the chromium species which can proceed after sampling before their determination the batch technique was found to be optimal because it enables the separation of the species directly at a sampling site and thus avoids the risk of the conversion of chromium species during sample pretreatment and transfer to the laboratory. The accuracy of the method was verified and the absence of appropriate reference material was overcome by the standard addition method in which both chromium species were added. Photometry with diphenylcarbazide solution as the additional alternative for validation of the proposed separation method was also applied to the determination of Cr(VI).

Full paper in Portable Document Format: 552a100.pdf

Chemical Papers 55 (2) 100–103 (2001)