Determination of methylmercury and estimation of total mercury in seafood using high performance liquid chromatography (HPLC) and inductively coupled plasma-mass ... [An article from: Analytica Chimica Acta]

This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
A method was developed for determination of methylmercury and estimation of total mercury in seafood. Mercury (Hg) compounds were extracted from 0.5g edible seafood or 0.2g lyophilized reference material by adding 50ml aqueous 1% w/v l-cysteine.HCl.H"2O and heating 120min at 60^oC in glass vials. Hg compounds in 50@ml of filtered extract were separated by reversed-phase high performance liquid chromatography using a C-18 column and aqueous 0.1% w/v l-cysteine.HCl.H"2O+0.1% w/v l-cysteine mobile phase at room temperature and were detected by inductively coupled plasma-mass spectrometry at mass-to-charge ratio 202. Total Hg was calculated as the mathematical sum of methyl and inorganic Hg determined in extracts. For seafoods containing 0.055-2.78mgkg^-^1 methylmercury and 0.014-0.137mgkg^-^1 inorganic Hg, precision of analyses was @?5% relative standard deviation (R.S.D.) for methylmercury and @?9% R.S.D. for inorganic Hg. Recovery of added analyte was 94% for methylmercury and 98% for inorganic Hg. Methyl and total Hg results for reference materials agreed with certified values. Limits of quantitation were 0.007mgkg^-^1 methylmercury and 0.005mgkg^-^1 inorganic Hg in edible seafood and 0.017mgkg^-^1 methylmercury and 0.012mgkg^-^1 inorganic Hg in lyophilized reference materials. Evaluation of analyte stability demonstrated that l-cysteine both stabilized and de-alkylated methylmercury, depending on holding time and cysteine concentration. Polypropylene adversely affected methylmercury stability. Total Hg results determined by this method were equivalent to results determined independently by cold vapour-atomic absorption spectrometry. Methylmercury was the predominant form of Hg in finfish. Ratios of methylmercury/total Hg determined by this method were 93-98% for finfish and 38-48% for mollusks.