Determination of total chromium in seawater by graphite furnace atomic absorption spectrometry

Abstract

Reported concentrations of chromium in open ocean waters range from 0.07 to 0.96 µg L"1, with a preponderance of values near the lower limit {1, and references summarized therein).

Determination of total chromium in seawater with isotope dilution sector field ICP-MS following on-line matrix separation

“…It has been earlier shown 9 that rapid reduction of Cr(VI) can be achieved using SO 2 water. Application of hydroxylammonium chloride 11 for this purpose was significantly more time consuming but quantitative reduction of Cr(VI) to Cr(III) could be achieved in 24 h at room temperature while avoiding the objectionable odor and toxicity of SO 2 .…”

“…Interest in measuring chromium in natural waters and effluents has increased due to concerns over the toxicity of Cr(VI) as a carcinogen. [2][3][4] Cr(VI) is a major form of inorganic Cr in natural waters 5 and typical concentrations in seawater [6][7][8][9][10][11][12][13][14] range from 50-200 pg g À1 , demanding highly sensitive and selective methods of quantitation.…”

“…12 Unfortunately, relatively poor precision, ranging from 13-40%, has been reported for Cr data in seawater using these techniques 12,15,16 principally because of dilution of its already low concentration. Separation and concentration using liquid extraction, 6,9,13,14 chelating imminodiacetate resins such as Muromac A-1 11 and Metpac CC-1 17 and 3M Empore disk, 19 silica-immobilized 8-hydroxyquinoline (I-8HOQ), 20 Dowex 50W-X8 anion exchange resin 21 and coprecipitation 22,23 with Mg(OH) 2 or Fe(OH) 3 have also been reported for this purpose. Many chelation-extraction systems are non-quantitative 19,20 (recoveries 10-50%) including Toyopearl AF Chelate 650 M resin (an iminodiacetate resin).…”

“…Many chelation-extraction systems are non-quantitative 19,20 (recoveries 10-50%) including Toyopearl AF Chelate 650 M resin (an iminodiacetate resin). 24,25 The objective of this study was to develop a simple and rapid on-line column separation method based on silica-immobilized diphenylcarbazone (I-DPC) 9 coupled with the high sensitivity and resolution offered by SF-ICP-MS to achieve accurate determination of Cr in seawater by isotope dilution calibration. The method was validated using seawater CRMs NASS-5 and CASS-4 and subsequently applied to the determination of Cr in candidate seawater CRMs NASS-6 and CASS-5.…”

Determination of Total Chromium in Seawater by Isotope Dilution Sector Field ICPMS Using GC Sample Introduction

“…[5][6][7][8][9][10][11][12] Commonly used techniques for total Cr assessment often involve some mode of preconcentration, such as chelation extraction, 5,[9][10][11] followed by quantitation using gas chromatography (GC), GC/ mass spectrometry (GC/ MS), and graphite furnace atomic absorption spectrometry (GFAAS) or following sorption on columns [6][7][8]12 with GFAAS, inductively coupled plasma atomic emission spectrometry (ICPAES), and inductively coupled plasma mass spectrometry (ICPMS) detection. 12 ICPMS has been used as a sensitive detector for Cr III and Cr VI determination in combination with chromatographic separation, 2,4,[12][13][14][15][16][17][18] but little information is available on the determination of total Cr in seawater by ICPMS, 12 in which concentrations are typically [5][6][7][8][9][10][11][12] in the range of 100-200 pg mL -1 . One of the most attractive features of ICPMS is its capability for determination of elemental isotopic composition.…”