Attenuated total reflectance FTIR detection and quantification of low concentrations of aqueous polyatomic anions.
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.
Hebert
Gretchen N
GN
Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA.
Odom
Matthew A
MA
Bowman
Stephanie C
SC
Strauss
Steven H
SH
D002138:Calibration; D015203:Reproducibility of Results; D017550:Spectroscopy, Fourier Transform Infrared; D014873:Water Pollutants / Q000032:analysis*
D014873:Water Pollutants