OFF-LINE COMBINATION OF RPHPLC AND TRACE MERCURY ANALYZER FOR ORGANOMERCURIAL SPECIATION IN ENVIRONMENTAL-SAMPLES

Performance of commercial Trace Mercury Analyser (TMA) originally devo ted to total mercury content analyses in solid and liquid samples was tested in off-line combination with HPLC technique for speciation purp oses. RPHPLC system optimized for baseline separation of mercury(II), methylmercury and phenylmercury rendered fractions with volumes direct ly acceptable by TMA. The main problems of this combination via off-li ne interfacing i.e. volatility of organomercurials and lost of fractio ns due to overflow from porous nickel and/or platinum transfer bents w ere solved by addition of wetting agent (cetyltrimethylammonium bromid e) and stabilizing agent (dithizone) into the vessels prior to fractio ns collection. Calibration curves were measured far Hg(II) and methylm ercury within range from 25 ppb to 500 ppb and were linear with correl ation coefficients better than 0.9997. Detection Limits achieved were around 0.3 ng for both mercury species. No matrix effects were observe d during analyses of tap and surface water samples spiked at low ppb l evels.