title: Eliminating interference from iron(III) for ultraviolet absorbance measurements of dissolved organic matter.
abstract: The presence of iron(III) has long been recognized as a difficulty when ultraviolet absorbance measurements of dissolved organic matter are desired. This interference was studied in water samples of diverse origins and properties, and a procedure is discussed which uses hydroxylamine to reduce up to 10 mg L(-1) (0.18 mM) of Fe(III) to non-interfering Fe(II). This procedure eliminated the effect of Fe(III) in all samples from about 220 to 400 nm, and removed interference down to 200 nm in most samples.
authors.affiliation: Department of Land, Air, and Water Resources, 1 Shields Avenue, University of California-Davis, Davis, CA 95616, USA. tadoane@ucdavis.edu
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Doane
authors.forename: William R
authors.initials: WR
authors.lastname: Horwáth
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry*; D019811:Hydroxylamine / Q000737:chemistry*; D009930:Organic Chemicals / Q000032:analysis; D010084:Oxidation-Reduction; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D014867:Water / Q000032:analysis
chemical_list: D005290:Ferric Compounds; D009930:Organic Chemicals; D014867:Water; D019811:Hydroxylamine