Determination of mercury in gasoline by photochemical vapor generation coupled to graphite furnace atomic absorption spectrometry

Abstract

Quantitation of mercury in gasoline by graphite furnace atomic absorption spectrometry following its photochemical vapor generation is described. Samples were prepared as a mixture of gasoline and propan-2-ol. A high efficiency flow through 19W photochemical vapor generator was used to process prepared samples with in-situ collection of the resultant Hg0 vapor onto reduced palladium in the graphite tube. Response from inorganic and organomercury standards added to the samples did not differ significantly. A limit of detection and characteristic mass of 0.1μgL−1 and 0.6ng were obtained, respectively. Relative standard deviations of replicate measurements of 3.0ngmL−1 added Hg(II) were typically 7–8%. Recoveries of spikes from samples ranged from 90 to 97%. The concentration of mercury in all tested samples of gasoline was below the limit of quantitation (0.3μgL−1). The method was rapid, efficient, green, fit-for-purpose, responsive to both inorganic and organic mercury species and should also respond to any Hg0 endogenously present in the sample.