Chromium speciation in solid matrices and regulation: a review

• Published in: Analytical and bioanalytical chemistry 2010-06, Vol.397 (3), p.1097-1111
• Main Authors: Unceta, N, Séby, F, Malherbe, J, Donard, O. F. X
• Format: Article
• Language: English
• Subjects: Air quality; Analysis; Analysis methods; Analytical Chemistry; Applied sciences; Biochemistry; Cement; Characterization and Evaluation of Materials; Chemical properties; Chemical Sciences; Chemical species; Chemistry; Chemistry and Materials Science; Chemistry, Analytic; Chromatography; Chromium; Chromium (Nutrient); Chromium - analysis; Chromium - isolation & purification; Chromium compounds; Control; Cr legislation; Electrochemical analysis; Environmental aspects; Environmental Monitoring - methods; Environmental Monitoring - standards; Equipment and supplies; Europe; Exact sciences and technology; Extraction (Chemistry); Food Science; Global environmental pollution; Health aspects; Hexavalent chromium; Identification and classification; Industrial toxicology; Ions; Laboratory Medicine; Laws, regulations and rules; Mathematical analysis; Matrices; Matrix methods; Methods; Monitoring/Environmental Analysis; Nutritional aspects; Occupational health and safety; Pollution; Properties; Quality management; Review; Soils; Solid matrix; Solid-liquid extraction; Speciation; Spectrometric and optical methods; Spectrum analysis; Wastes
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-009-3417-1

In recent years, the extensive use of chromium in industrial processes has led to the promotion of several directives and recommendations by the European Union, that try to limit and regulate the presence of Cr(VI) in the environment and to protect industrial workers using chromium and end-users of manufactured products. As a consequence, new standard methods and analytical procedures have been published at the EU level for Cr(VI) determination in soil, sludge, sediment, and similar waste materials, workplace atmospheres, cement, packaging materials, industrially produced samples, and corrosion-protection layers on some components of vehicles and electrical and electronic equipment. The objective of this article is to summarize the different directives and recommendations and to critically review the currently existing standard methods and the methods published in the literature for chromium speciation in the above mentioned solid matrices, putting the emphasis on the different extraction procedures which have been developed for each matrix. Particular attention has been paid to Cr(III) and Cr(VI) inter-conversions that can occur during extraction and efforts to minimize these unwanted reactions. Although the use of NaOH-Na₂CO₃ solutions with hot plate extraction seems to be the more widespread procedure, species transformation can still occur and several studies suggest that speciated isotope-dilution mass spectrometry (SIDMS) could be a suitable tool for correction of these interconversions. Besides, recent studies have proved the role of Cr(III) in chromium toxicology. As a consequence, the authors suggest an update of standard methods in the near future.