Tadeja Milivojevič Nemanič,a Lucija Zupančič-Kralj,b Radmila Milačič,a Janez Ščančara*
a
Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000
Ljubljana, Slovenia.
E-mail: janez.scancar@ijs.si.
b
University of Ljubljana, Faculty of Chemistry and Chemical Technology, Aškerčeva
5, 1000 Ljubljana, Slovenia
Paper based on a
presentation at the 12th International Symposium on Separation
Sciences, Lipica, Slovenia,
September 27–29, 2006.
Abstract
The efficiency of
different extraction procedures for the simultaneous determination of organotin
compounds in mussels
Mytilus galloprovincialis
by gas
chromatography – mass spectrometry was critically evaluated. Three different
solvents, hydrochloric acid (0.1 mol L–1, 0.5 mol L–1 and
1 mol L–1) in methanol, acetic acid (0.5 mol L–1, 5 mol L–1
and 13 mol L–1) in methanol and a 25% aqueous solution of
tetramethylammonium hydroxide, and three different extraction approaches of
mechanical shaking, ultrasonic and closed vessel microwave-assisted extraction
were used for the extraction of organotin compounds from ERM-CE477 certified
mussel tissue reference material. Before determination by GC-MS, extracted
organotin species were derivatised with sodium tetraethyl borate and extracted
into iso-octane. The results of analyses of ERM-CE477 reference material
obtained after the different extraction procedures indicated that 1h of
ultrasonic extraction at 50 °C with 0.1 mol L–1 hydrochloric acid in
methanol as extraction solvent provided satisfactory recoveries for all
organotin compounds certified in this reference material.
The analytical method developed was successfully applied to determination of
organotin compounds in mussels
Mytilus galloprovincialis
from the
Slovenian costal area. Butyltins were found in mussels from all locations
investigated. Among them, the highest concentration was of tributyltin, reaching
1100 ng Sn g–1 (dry mass).
Keywords: organotin compounds, mussels, extraction procedures, GC-MS