|Abstract Title:||Distillation as Isolation Method for the Determination of Methyl Mercury Compounds in Urine Samples|
|Presenter Name:||Adna Alilović|
|Company/Institution:||International postgraduate school Jožef Stefan|
|Session:||Human Exposure and Risk Assessment of Hg|
|Co-Authors:||Adna Alilović,Milena Horvat|
Abstract Information :
Mercury is a naturally-occurring element, found in the environment in different states and chemical forms. Each of them has a unique toxicological profile, mechanism of transport and deposition in the body, as well as different metabolic fate. For good understanding of mercury?s toxicity, it is essential to determine not only its total amount, but also the amount of the existing species in different biological matrices. Speciation analysis has become indispensable part of reasonable and reliable risk assessment. In the present study, speciation analysis of urine samples was conducted. Isolation of methylmercury compounds (MeHg) from urine samples by distillation, followed by aqueous phase ethylation, precollection on Tenax trap, isothermal gas chromatography, pyrolysis and cold vapour atomic fluorescence spectrometry (CVAFS) detection was investigated. Moreover, results obtained by distillation were compared with ones obtained by acid digestion (4 M HNO3) method. A good agreement of results obtained by the two methods was found in samples with MeHg concentration above 2 pg g-1 urine, which is the limit of detection of the acid digestion method. In comparison, limit of detection for the distillation method was estimated at 1 pg g-1 urine. Distillation gave consistent and high recoveries (91ñ4%) and provided more accurate results at low MeHg concentrations. In addition to this, distillation provides significant savings in sample preparation time, as samples can be prepared and measured the same day. Finally, it enables avoidance of matrix interferences that are the most important limitation of acid digestion, especially when determining low MeHg levels.