Determination of nitrate and nitrite in Hanford defense waste (HDW) by reverse211 polarity capillary zone electrophoresis (RPCE) method

摘要

This paper describes the first application of reverse polarity capillary zone211u001eelectrophoresis (RPCE) for rapid and accurate determination of nitrate and 211u001enitrite in Hanford Defense Waste (HDW). The method development was carried out by 211u001eusing Synthetic Hanford Waste (SHW), followed by the analysis of 4 real HDW 211u001esamples. Hexamethonium bromide (HMB) was used as electroosmotic flow modifier in 211u001eborate buffer at pH9.2 to decrease the electroosmotic flow (EOF) in order to 211u001eenhance the speed of analysis and the resolution of nitrate and nitrite in high 211u001eionic strength HDW samples. The application of this capillary zone 211u001eelectrophoresis method, when compared with ion chromatography for two major 211u001ecomponents of HDW, nitrate and nitrite slightly reduced analysis time, eliminated 211u001emost pre-analysis handling of the highly radioactive sample, and cut analysis 211u001ewastes by more than 2 orders of magnitude. The analysis of real HDW samples that 211u001ewere validated by using sample spikes showed a concentration range of 1.03 to 211u001e1.42 M for both nitrate. The migration times of the real HDW and the spiked HDW 211u001esamples were within a precision of less than 3% relative standard deviation. The 211u001eselectivity ratio test used for peak confirmation of the spiked samples was 211u001ewithin 96% of the real sample. Method reliability was tested by spiking the 211u001ematrix with 72.4mM nitrate and nitrite. Recoveries for these spiked samples were 211u001e93-103%.