Determination of Cr(VI) in welding fumes by anion-exchange fast protein liquid chromatography with electrothermal atomic absorption spectrometric detection

Abstract

The applicability of an anion-exchange fast protein liquid chromatographic-electrothermal atomic absorption spectrometric procedure (FPLC-ETAAS) was investigated for the determination of Cr(VI) in welding fumes after alkaline extraction of aerosols loaded on filters. Gas tungsten arc welding (GTAW) of stainless steel was applied. Samples of welding fumes were collected during regular welding on polycarbonate membrane filters of 8 microm and 0.4 microm pore size (inhalable and respirable aerosols). Alkaline extraction (2% NaOH-3% Na2CO3) of filters in a heated ultrasonic bath was applied to leach Cr from the airborne particulate matter. 0.5 cm3 of sample extract was then injected onto an anion-exchange FPLC column. Tris-HCl buffer (0.005 mol dm(-3), pH 8.0) and the same buffer with NaCl (0.5 mol dm(-3)) were employed in gradient elution (15 min, flow rate 1 cm3 min(-1)). The separated Cr species were determined "off line" by ETAAS in 0.5 cm3 fractions. Cr(VI) was reproducibly and quantitatively eluted from 12.0 to 13.0 min with a maximum peak at 12.5 min. Good repeatability of measurement (+/-3.0%) of alkaline extracts was obtained for Cr(VI). The LOD (3s) was found to be 0.035 microg m(-3) Cr(VI), when 2 m3 of aerosols were collected on the filter. Validation of the procedure was performed by spiking alkaline extracts and by the analysis of standard reference material CRM 545, Cr(VI) in welding dust loaded on a filter. The technique was successfully applied for the determination of Cr(VI) in welding fumes.

Chemical Speciation of Chromium(III) and (VI) Using Phosphonium Cation Impregnated Polyurethane Foams Prior to Their Spectrometric Determination

“…According to the IUPAC, 39 the lower limits of detection (LOD = 3Sy/x/b) and quantification (LOQ = 10Sy/x/b) were found to be equal 0.04 and 0.13 μg L -1 , respectively where Sy/x is the standard deviation of y-residual and b the slope of the calibration plot. 37 The LOD is far below the permissible limit of chromium by most of the reported methods [10][11][12][13][14][15][16][17] and the values of Cr(VI) at 0.05 and 0.2 ng mL -1 in fresh and marine water samples, respectively. The LOD is sufficiently low as compared to those attained by AAS (9.0 μg L -1 ) and ICP-OES (1.0 μg L -1 ).…”

“…The analytical features of the proposed method were showed excellent performance compared with most of the reported methods. 10,16 Some of these methods exhibited high detection limits in the range of 0.01 -7.5 μg L -1 . 23 Hence, the developed method is simple and less toxic, and provides an effective approach for the chemical speciation of Cr(III) and Cr(VI).…”

“…clay minerals, gelatin, biosorbent, and active carbon, synthetic polymers, C18-bonded silica, silica gel immobilized with Zr(IV) and Zr(VI) phosphate have been used for preconcentration and/or separation of trace and ultra trace amounts of toxic metal ions from complex matrices. [8][9][10][11][12][13][14][15] Determination and chemical speciation of Cr(III) and Cr(VI) at trace levels in welding fumes and in drinking water samples using strong anion ion-exchange, 16 neutral alumina, 17 mini-columns packed with resin immobilized with 8-hydroxyquinoline, 18 activated carbon, 19 leaching procedure with sodium carbonate 5 and drawn and modified lingo cellulosic materials 20,21 have been reported. However, some of these SPE methods [10][11][12][13][14][15] are too expensive or unselective; they require careful experimental conditions, are time consuming and are not compatible with the detection limit of Cr(VI) in various matrices.…”

Development of Analytical Procedure for the Determination of Exchangeable Cr(VI) in Soils by Anion-exchange Fast Protein Liquid Chromatography with Electrothermal Atomic Absorption Spectrometry Detection

“…Cr (VI) was eluted between 10.5 and 11.5 min with a maximal peak at 11.0 min. Positively charged Cr(III) species were eluted with the solvent front, while the hydroxo Cr(III) species were strongly adsorbed on the column resin Milačič et al 2002). The column was regenerated with 2 mol l −1 NaCl for 5 min and equilibrated with buffer A in the following 10 min at a flow rate of 1.0 ml min −1 .…”

Retention Profile of Mercury (II) Ions from Aqueous Solution onto Some Selected Local Solid Sorbents

“…The sorption behavior of heavy metals and their differential determination employing C18-bonded silica as the column material and silica gel surface immobilized with zirconium (IV) and zirconium (VI) phosphate have been studied [2][3][4][5] . The Determination of mercury (II) at trace levels in welding fumes employing a strong anion-exchange containing hydrophilic polyether resin substituted with quaternary amine groups has been reported [6] . The chemical speciation and determination of trace of metal ions present in aqueous solution employing solid extractors such as an adsorbent in column mode has been performed [7][8][9] .…”