title: Determination of CMPO using HPLC-UV.
abstract: Octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) is an extractant proposed for selective separation of radionuclide metals from used nuclear fuel solutions using solvent extraction. Radiolysis reactions can degrade CMPO and reduce separation performance and hence methods for measuring the concentration of CMPO are needed. A novel high performance liquid chromatography (HPLC) method was developed for measuring CMPO in dodecane that featured a low pH buffer, octanol as a co-solvent with 2-propanol, and ultraviolet (UV) detection. Validation data indicated that the HPLC-UV method for CMPO determination provided good linearity, sensitivity, accuracy and precision. Method performance was evaluated using CMPO samples that had undergone radiolysis, and the results showed a decrease in CMPO concentration and the appearance of degradation products. The degradation products were identified using electrospray ionization mass spectrometry, which also showed formation of CMPO-nitric acid complexes that account for the apparent loss of CMPO in an acidic environment, independent of irradiation.
authors.affiliation: Idaho National Laboratory, Chemical and Radiation Measurement Department, P.O. Box 1625, Idaho Falls, ID 83415-2213, USA. gracy.elias@inl.gov
authors.forename: Gracy
authors.initials: G
authors.lastname: Elias
authors.forename: Gary S
authors.initials: GS
authors.lastname: Groenewold
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: Mincher
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Mezyk
mesh_terms: D019840:2-Propanol / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D057230:Limit of Detection; D016014:Linear Models; D008970:Molecular Weight; D017942:Nitric Acid / Q000737:chemistry; D000442:Octanols / Q000737:chemistry; D010720:Phosphines / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*
chemical_list: C528537:(N,N-diisobutylcarbamoylmethyl)phenyloctylphosphine oxide; D000442:Octanols; D010720:Phosphines; D017942:Nitric Acid; D019840:2-Propanol