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Speciation Analysis of Cr(III) and Cr(VI) after Solid Phase Extraction Using Modified Magnetite Nanoparticles
Author(s) -
Karimi Mohammad Ali,
Shahin Rasul,
Mohammadi Sayed Zia,
HatefiMehrjardi Abdolhamid,
Hashemi Javad,
Yarahmadi Javad
Publication year - 2013
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.201200669
Subject(s) - chemistry , chromium , detection limit , solid phase extraction , adsorption , magnetite , bromide , enrichment factor , extraction (chemistry) , atomic absorption spectroscopy , chromatography , analytical chemistry (journal) , nuclear chemistry , inorganic chemistry , metallurgy , materials science , physics , organic chemistry , quantum mechanics
A new solid phase extraction (SPE) method has been developed for the speciation of Cr(III) and Cr(VI). This method is based on the adsorption of Cr(VI) on modified alumina‐coated magnetite nanoparticles (ACMNPs). Total chromium in different samples was determined as Cr(VI) after oxidation of Cr(III) to Cr(VI) using H 2 O 2 . The chromium concentration has been determined by flame atomic absorption spectrometric (FAAS) technique and amount of Cr(III) was calculated by substracting the concentration of Cr(VI) from total chromium concentration. The effect of parameters such as pH, amount of adsorbent, contact time, sample volume, eluent type, H 2 O 2 concentration and cetyltrimethylammonium bromide (CTAB) concentration as modifier on the quantitative recovery of Cr(VI) were investigated. Under the optimal experimental conditions, the preconcentration factor, detection limit, linear range and relative standard deviation (RSD) of Cr(VI) were 140 (for 350 mL of sample solution), 0.083 ng mL −1 , 0.1‐10.0 ng mL −1 and 4.6% (for 5.0 ng mL −1 , n = 7), respectively. This method avoided the time‐consuming column‐passing process of loading large volume samples in traditional SPE through the rapid isolation of CTAB@ACMNPs with an adscititious magnet. The proposed method was successfully applied to the determination and speciation of chromium in different water and wastewater samples and suitable recoveries were obtained.