Quantification of hydroxide in aqueous solutions by Raman spectroscopy
Conference
·
OSTI ID:634000
Quantification of hydroxide in aqueous solutions by Raman spectroscopy is complicated by the fact that the O-H stretching band of hydroxide is overlapped by the broad, symmetric O-H stretching band of water. This overlap is further complicated by the fact that the shape of the O-H stretching band of water is strongly influenced by the concentration of hydroxide. The O-H stretching band of water is believed to consist of five components that result from differing configurations of intramolecular hydrogen bonding. The Raman spectral region from 300 to 4,450 cm{sup {minus}1} was investigated for NaOH solutions ranging in concentration from 0.2 to 50 weight percent. At approximately 5 weight percent NaOH, a distinct shoulder appears on the high energy side of the O-H stretching band of water. As the NaOH concentration increases, this shoulder becomes a sharp distinct band at 3,600 cm{sup {minus}1} which is still not resolved from the O-H stretching band of water. As the O-H stretching band of hydroxide increases, the O-H stretching band of water broadens and its contour becomes smoother. By curve fitting five Gaussian functions to the O-H stretching band of water, the asymmetric band due to hydroxide was extracted from the composite band of the NaOH solution. The curve fitting routine resulted in a linear relationship for the area of the hydroxide band in the concentration range from 5 to 50 weight percent NaOH. The uncertainty in the curve fitting at concentrations below 5 weight percent was too large to establish a reliable calibration curve. Below 5 weight percent NaOH, direct spectral subtraction of the water band from the NaOH solution band resulted in a linear relationship in the range of 5 down to 0.2 weight percent NaOH. The peak shape obtained for the hydroxide band by the two different techniques was very similar. A comparison of the results obtained from peak fitting and spectral subtraction is presented.
- Research Organization:
- Bettis Atomic Power Lab., West Mifflin, PA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States); USDOE Assistant Secretary for Nuclear Energy, Washington, DC (United States)
- DOE Contract Number:
- AC11-93PN38195
- OSTI ID:
- 634000
- Report Number(s):
- WAPD-T--3169; CONF-980310--; ON: DE98002720
- Country of Publication:
- United States
- Language:
- English
Similar Records
Application of FT-IR /sup 13/C NMR spectroscopy to the determination of structural parameters in coals and vitrinite concentrates
Raman spectra of the water stretching frequencies in rare earth chloride solutions as a function of concentration
Thesis/Dissertation
·
Fri Dec 31 23:00:00 EST 1982
·
OSTI ID:6206568
Raman spectra of the water stretching frequencies in rare earth chloride solutions as a function of concentration
Thesis/Dissertation
·
Tue Oct 31 23:00:00 EST 1972
·
OSTI ID:4598855