Short communication, Note
Decomposition of Fish Samples for Determination of Mercury
Ljerka Prester
Diana Jureša
Maja Blanuša
Abstract
The aim of the study was to compare the efficiency of acid and alkaline decomposition of biological materials using an open and a closed system for total mercury determination. Acid digestion was performed with concentrated HNO3 in tubes at 80 ºC and lasted five hours. Alkaline digestion was performed with a 45% NaOH and a 1% cysteine, heated at 120 ºC for 20 minutes. Total mercury was measured by atomic absorption spectrometry using the cold vapour technique (CVAAS). The average recovery obtained for analysis of certified reference material in closed tubes for acid digested sample was superior to the alkaline one, 103±4% vs. 70±3%, respectively. In addition, the recoveries through the open system acid digestion (90±8%) and the open system alkaline digestion (57±2%) were lower than through the respective closed system digestions. Reproducibility of the acid decomposition method was superior to the alkaline one.
Keywords
acid digestion; alkaline digestion; biological material; closed system; cold vapour atomic absorption spectrometry; fish; mercury; mercury recorvery; open system
Hrčak ID:
3265
URI
Publication date:
13.5.1999.
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