Determination of methylmercury and mercury(II) in a marine ecosystem using solid-phase microextraction gas chromatography-mass spectrometry

A solvent free solid-phase microextraction (SPME) method has been developed to determine methyl mercury and Hg(II) in sediment, seawater and biota samples from TTC area (Mumbai, India) using gas chromatograph-mass spectrometer (GC-MS). The analytical method consists of phenylation with Na[B(C6H5)4], simultaneous solid-phase microextraction of the derivatives, followed by a final GC-MS analysis. Experimental design methodology was used for optimization of important process parameter, like SPME fiber coating (nature and thickness), extraction time, extraction temperature, and pH. After extraction, the fiber is directly injected to the injector port of GC for desorption, separation and quantification. The absolute detection limits obtained for methylmercury and inorganic mercury were 0.02 and 0.05 ng as Hg, respectively. Standard reference materials were analyzed for validation of the methodology. The total mercury content in different matrices was determined using hydride generation atomic adsorption spectrometry (HG-AAS).