title: Attenuated total reflectance FTIR detection and quantification of low concentrations of aqueous polyatomic anions.
abstract: Development of a new quantitative method for determining low concentrations of aqueous polyatomic anions using attenuated total reflectance (ATR) FTIR spectroscopy is described. Evaporated thin-film coatings of anion-selective tetraalkylated ferrocenium salts were applied to the surface of ATR crystals, which enabled anion detection limits to be lowered up to 23 000-fold below those achieved using the commercially available spectrometer with identical uncoated ATR crystals. Linear calibration curves based on d(absorbance)/dt, which is related to the rate of anion exchange in the thin film, were established in the 0.04-30 microM range. Limits of detection (10-min analyses) for perchlorate, chlorate, trifluoromethanesulfonate, perfluoro-n-butanesulfonate, perfluoro-n-octanesulfonate, tetrafluoroborate, hexafluorophosphate, and pinacolylmethylphosphonate in aqueous solution were 0.03, 0.2, 0.05, 0.07, 0.06, 0.06, 0.6, and 0.7 microM, respectively, using the thin-film coatings. This simple detection/quantification method afforded good reproducibility with relatively fast detection times.
authors.affiliation: Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: Gretchen N
authors.initials: GN
authors.lastname: Hebert
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Odom
authors.forename: Stephanie C
authors.initials: SC
authors.lastname: Bowman
authors.forename: Steven H
authors.initials: SH
authors.lastname: Strauss
mesh_terms: D002138:Calibration; D015203:Reproducibility of Results; D017550:Spectroscopy, Fourier Transform Infrared; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D014873:Water Pollutants