Sampling and analysis considerations for the determination of hexavalent chromium in workplace airThis article was prepared by governmental employees of the United States of America and the United Kingdom as part of their official duties, and legally may not be copyrighted in the USA or the UK.

Abstract

Airborne hexavalent chromium (Cr[VI]) is a known human respiratory carcinogen and allergen. Workers in a variety of industries may be exposed to airborne hexavalent chromium, with exposures frequently occurring via inhalation and/or dermal contact. Analytical methods for the measurement of Cr(VI) compounds in workplace samples, rather than for the determination of total elemental chromium in workplace air, are often desired because exposure limit values for Cr(VI) compounds are much lower than for total Cr. For years, sampling and analytical test methods for airborne Cr(VI) have been investigated so as to provide means for occupational exposure assessment to this highly toxic species. Inter-conversion of trivalent chromium (Cr[III]) and Cr(VI) can sometimes occur during sampling and sample preparation, and efforts to minimize unwanted redox reactions involving these chromium valences have been sought. Because of differences in toxicity, there is also interest in the ability to differentiate between water-soluble and insoluble forms of Cr(VI), and procedures that provide solubility information concerning Cr(VI) compounds have been developed. This paper reviews the state of the art concerning the measurement of airborne Cr(VI) compounds in workplace aerosols and related samples.

Determination of hexavalent chromium in exhaled breath condensate and environmental air among chrome plating workers

“…Furthermore, the website of the National Institute for Occupational Safety and Health (NIOSH) shows various protocols for determining Cr(VI) in environmental air [23], and a comparison of the different analytical methods [24]. The state of the art concerning the measurement of airborne Cr(VI) compounds in workplace aerosols and related samples has recently been reviewed [25]. Cr(VI) has never been assayed in EBC after exposure to hexavalent Cr compounds.…”

Cr(VI) Generation During Flaring of CO-Rich Off-Gas from Closed Ferrochromium Submerged Arc Furnaces

“…Cr(VI) compounds can be classified as water soluble and water insoluble. [29] Therefore, to accurately determine the total Cr(VI) concentrations, both water soluble and water insoluble compounds had to be extracted. This was achieved by conducting hotplate digestion extraction with a sodium carbonate and sodium hydroxide buffer solution, as suggested by Ashley et al This buffer was prepared by dissolving 60 g sodium carbonate and 40 g sodium hydroxide in a 2 L volumetric flask.…”

“…A hot alkaline extraction solution saturated with air could lead to in situ formation of Cr(VI) in the presence of Cr(III). [29] Therefore, in order to prevent the unwanted oxidation of Cr(III), extraction solutions and the headspace of the extraction container were purged with N 2 prior to, during, and after Cr(VI) extraction. After extraction, the solutions were purged until the solution cooled down to room temperature.…”

“…[30] In addition to the excellent detection limit, the analytical procedure utilized also prevented false positive Cr(VI) values, which is common with the direct DPC UV-visible method. [29] The IC eluent was prepared by dissolving 66 g ammonium sulfate and 15.08 g ammonium hydroxide in 2 L deionized water. The DPC colorant was prepared by adding 28 mL 98 pct sulfuric acid to approximately 100 mL deionized water in a 1 L volumetric flask.…”

An Investigation on the Extraction and Quantitation of a Hexavalent Chromium in Acrylonitrile Butadiene Styrene Copolymer (ABS) and Printed Circuit Board (PCB) by Ion Chromatography Coupled with Inductively Coupled Plasma Atomic Emission Spectrometry

“…Chromium is one of them because trivalent chromium (Cr (III)) is very essential in nutrition, but hexavalent chromium (Cr VI) is very toxic to human beings. [1][2][3][4][5][6][7] Thus, the concentration of Cr (VI) in drinking water has been restrictly regulated in the world. The RoHS (Directive on the Restriction of the use of Hazardous Substances in electrical and electronic equipment) also regulated the Cr (VI) in electrical and electronic products.…”