Laser excitation kinetic phosphorimetry for uranium analysis
Laser induced phosphorescence with time resolved photon counting detection has been used to measure uranium, as uranyl phosphate, in aqueous solution at room temperature. Demonstrated detection limits are below 10 parts per trillion. Multichannel scaler (MCS) photon counting is used for the rejection of laser and raman scattering, discrimination against prompt fluorescing species such as organics, and to provide a simultaneous determination of the uranyl emission lifetime. The lifetime is then used as a direct (photophysically correct) instrumental correction for matrix quenching and temperature effects. The MCS counting mode also allows rapid measurements (a few seconds at the ppb level, 5 minutes for pptr). Sample volumes of 2 to 3 ml have been used although 1/2 ml would be sufficient. The method has been used for: (1) evaluating uranium contamination in ultrapure solvents and trace analytical procedures, in the low part per trillion range, (2) directly measuring (without chemical pretreatment or separation) urine samples at the 10 ppb level, (3) direct measurements on drinking and ground waters at the sub ppb level, and (4) using oxidative digestion as the only preparation, both urine and brine waters have been measured at the sub ppb level. For the brine water analysis the determined value (0.36 ppb) agreed within 10% of the number determined by U-233 tracer - iron hydroxide coprecipitation - filament source mass spectrometric analysis.
- Research Organization:
- Pacific Northwest Lab., Richland, WA (USA)
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 6021985
- Report Number(s):
- PNL-SA-11294; ON: DE85005529
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400100 -- Analytical & Separations Chemistry
440300* -- Miscellaneous Instruments-- (-1989)
47 OTHER INSTRUMENTATION
ACTINIDE COMPOUNDS
ACTINIDES
BIOLOGICAL MATERIALS
BIOLOGICAL WASTES
BODY FLUIDS
CHEMICAL ANALYSIS
ELEMENTS
HYDROGEN COMPOUNDS
LASER SPECTROSCOPY
MATERIALS
METALS
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS COMPOUNDS
SOLVENTS
SPECTROSCOPY
URANIUM
URANIUM COMPOUNDS
URANYL COMPOUNDS
URANYL PHOSPHATES
URINE
WASTES
WATER