On-line high-performance liquid-chromatographic separation and cold vapor atomic absorption spectrometric determination of methylmercury and inorganic mercury

• Published in: Talanta (Oxford) 1999-02, Vol.48 (2), p.477-484
• Main Authors: Rı́o-Segade, S., Bendicho, C.
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Cold vapor atomic absorption spectrometry; Exact sciences and technology; High-performance liquid chromatography; Inorganic mercury; Methylmercury; Other chromatographic methods
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/S0039-9140(98)00269-0

A reversed-phase high-performance liquid chromatography (HPLC) method with cold vapor atomic absorption spectrometry (CV-AAS) detection is developed for mercury speciation. In this paper, the efficiency of tetrabutylammonium bromide reagent and sodium chloride in a methanol–water mixture as mobile phase is evaluated for HPLC separation of methylmercury and inorganic mercury coupled with on-line CV-AAS determination. Both mercury species are separated on a reversed-phase C 18 column. Several parameters (e.g. composition and flow-rate of mobile phase) are investigated for the optimization of HPLC separations. CV-AAS technique parameters are also studied for their effect on sensitivity (sodium borohydride and sodium hydroxide concentrations in the reducing agent, reducing agent flow-rate, length of the reduction coil and nitrogen flow-rate). Quantitative recoveries for both inorganic mercury and methylmercury are obtained from a spiked natural water sample.