Box , Beijing, , P. E-mail: chw gmail. This method requires minimal sample pretreatment and no high resolution instruments. The typical time for analysis of a single liquid sample was about 5 min since the prepared sample solutions were directly infused into the EESI source without separation or preconcentration.
The relative errors for uranium isotope measurements were in the range of 0. These findings confirmed that EESI-MS can be employed for quantitative measurement inorganic compounds present in a complex matrix. The fast detection of uranium isotopes shows potential applications of EESI-MS in nuclear research laboratories and the nuclear energy industry.
Currently, methods including potentiometric titration , 16β18 photometry, 19 and polarography 20β22 etc. Generally these methods are not highly sensitive and are time-consuming. Mass spectrometry MS is a relatively universal method with high sensitivity and good selectivity; however, uranyl compounds are inorganic analytes, which are commonly in solutions with complex matrices and are incompatible with most commercially available ionization techniques.
Inductively coupled plasma mass spectrometry ICPMS 23β25 and isotope ratio mass spectrometry IR-MS are two widely used mass spectrometric methods for the analysis of uranyl compounds. For most liquid samples containing complex matrices, multi-step sample pretreatments such as solvent extraction , ion exchange, and coprecipitation 27,28 is usually required prior to ICP-MS experiments.
The sample pretreatment steps may decrease detection sensitivity, introduce chemical impurities, and even alter oxidation states of the analytes of interest. Therefore, it would be interesting to develop novel methodologies for the rapid detection of uranium species with high sensitivity and high specificity. In , Cooks et al. Unlike the 2-D techniques e. Therefore, EESI tolerates extremely complex matrices and it has been used to analyze complicated mixtures such as milk, urine, explosives , and aerosol drugs.
