Monitoring hydrofluoric acid activity by vapor-phase infrared spectroscopy

Journal Article · Fri Jul 01 04:00:00 EDT 1994 · Applied Spectroscopy; (United States)

DOI:https://doi.org/10.1366/0003702944029947· OSTI ID:7177943

Brenneman, K R; Donohoe, R J ^[1]

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1. Spectroscopy and Biochemistry Group, CST-14 MS-C345, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

Infrared spectra of the vapor phase over solutions approximating those used in the dissolution of plutonium, typically 10 M in nitric acid and 0.2 M in hydrofluoric acid, reveal that the hydrofluoric acid (HF) activity can be monitored in a facile and noninvasive manner. The amount of vaporized HF is strongly dependent upon the nitric acid content; the vapor-phase HF content over a series of solutions in which the HF concentration is held constant at 0.5 M increases by a factor of nearly 25 as the HNO[sub 3] concentration is increased from 0 to 14 M. This effect is due to changes in the HF activity and is not a result of changes in the heat of vaporization, which was measured (by van't Hoff plots) to be 9.4[plus minus]0.6 kcal/mole for 16 mock process solutions ranging from 0.01 to 0.1 M HF and 8 to 14 M HNO[sub 3]. This result demonstrates that spectroscopic methods can use the vaporization of an analyte to measure the activity rather than the concentration.

• OSTI ID: 7177943
• Journal Information: Applied Spectroscopy; (United States), Journal Name: Applied Spectroscopy; (United States) Vol. 48:7; ISSN 0003-7028; ISSN APSPA4
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
ACTINIDES
ELEMENTS
FLUIDS
FLUORINE COMPOUNDS
FOURIER TRANSFORM SPECTROMETERS
GASES
HALOGEN COMPOUNDS
HYDROFLUORIC ACID
HYDROGEN COMPOUNDS
INFRARED SPECTRA
INORGANIC ACIDS
MEASURING INSTRUMENTS
METALS
PLUTONIUM
SPECTRA
SPECTROMETERS
TRANSURANIUM ELEMENTS
VAPORS