Speciation of inorganic selenium using capillary electrophoresis–inductively coupled plasma-atomic emission spectrometry with on-line hydride generation

A novel and simple hydride generator has been developed. The hydride generator has good stability and high gas liquid separation efficiency. The generator serves as an interface of capillary electrophoresis (CE) and inductively coupled plasma atomic emission spectrometry (ICP-AES). This device eliminates the nebulization step and overcomes the common problem of suction flow resulting from the use of nebulization gas in ICP. Selenium compounds that were separated by CE were converted into the corresponding volatile hydrides, followed by ICP-AES measurement. The effects of the concentration of the hydride generating reagents (HCl and NaBH4), the carrier gas flow rate, and heavy metal interference on Se emission intensity were discussed. The relative standard deviations (RSDs) of peak area, based on six determinations of 50 ng mL−1 standard of SeIV and SeVI, were 1.5% and 1.8%, respectively. The detection limits (3σ) of peak area were 2.1 ng mL−1 and 2.3 ng mL−1 for SeIV and SeVI, respectively. Speciation analysis of inorganic SeIV and SeIV species using the HG-CE–ICP-AES system was demonstrated in tap and river water samples.