2026-04-17T20:41:55Zhttps://recercat.cat/oai/request

oai:recercat.cat:10256/229562024-06-18T13:58:10Zcom_2072_452955com_2072_2054col_2072_453073

00925njm 22002777a 4500 dc Marguí Grabulosa, Eva author Torrent Fàbrega, Laura author 2023-06 In the present contribution, a simple and inexpensive method for the determination of hexavalent chromium in aqueous solutions was developed. The analytical methodology consists of the combined use of a low cost Cr(VI) isolation procedure followed by the analysis using total reflection X-ray spectrometry (TXRF). The liquid-liquid microextraction procedure (LLME) used is based on the formation of an ion-pair between the cationic part of the surfactant cetyltrimethylammonium bromide (CTAB) and the corresponding anionic Cr(VI) species, which is extracted in few microliters of chloroform. TXRF analysis can be performed directly by deposition of 15 μL of the preconcentrated sample on a sample carrier, without any additional sample treatment. Experimental parameters affecting Cr(VI) extraction and TXRF analysis were studied in detail. Under optimum conditions, a good linearity was obtained in the range of 5–5000 μg/L with a limit of detection for hexavalent chromium of 0.9 μg/L. This fact opens the possibility of Cr determination in aqueous samples characterized by different concentration levels. The methodology was successfully applied for the determination of Cr(VI) species in different type of water matrices (tap, well, river and sea water) as well as industrial aqueous samples including in industrial waste water from a galvanic industry and aqueous clinker extracts. For comparison purposes, the determination of Cr(VI) in industrial samples was also carried out by using the colorimetric method EPA Method 7196 This work was supported by the grant PID2021-127326OB-I00 funded by MCIN/AEI/ 10.13039/501100011033 Open Access funding provided thanks to the CRUE-CSIC agreement with Elsevier http://hdl.handle.net/10256/22956 Espectroscòpia de fluorescència Photoelectron spectroscopy Espectroscòpia de raigs X X-ray spectroscopy Extracció (Química) Extraction (Chemistry) Simple method for Cr(VI) determination by liquid-liquid microextraction combined with total reflection X-ray fluorescence spectrometry: Application to water samples and industrial extracts