Selenium speciation in ginger using capillary electrophoresis online coupled with electrothermal atomic absorption spectrometry
Abstract
A novel and sensitive selenium speciation in cultivated ginger rhizomes was developed using capillary electrophoresis coupled with electrothermal atomic absorption spectrometry. Influencing parameters were experimentally investigated. Under optimal conditions, SeMet, SeCys2, SeIV, and SeVI were completely separated when using capillary electrophoresis electrothermal atomic absorption spectrometry. Detection limits of SeMet, SeCys2, SeIV, and SeVI were 1.7, 2.2, 0.89, and 0.97 ng mL−1, respectively. The recoveries ranged from 95.6% to 104%. The RSD of peak height was observed to be smaller than 5%. When selenium enrichment was used on ginger, SeMet, SeIV, and SeVI could be detected in the first month; in the second month, the concentration of SeCys2, as well as the concentrations of SeMet, SeIV, and SeVI, could be determined. Ginger absorbs SeO32− and SeO42− at different rates; they could be converted into the organic selenium species.