| Abstract [eng] |
The aim of the study was to examine possibilities of liquid-liquid microextraction methods for fast and efficient extraction of organotin compounds (OTC) and to prepare and apply the most appropriate technique for the analysis of aqueous samples. In real samples OTC exist in cationic form, are non-volatile and polar, so before gas chromatographic analysis OTC must be derivatized. Sodium tetraethylborate has been used for the derivatization. Derivatization conditions (pH, derivatization time, derivatization reagent concentration) have been examined, gas chromatographic-mass spectrometric conditions for derivatized OTC have been optimized. Possibilities to apply three liquid-liquid microextraction techniques – dispersive liquid-liquid microextraction, microextraction based on the solidification of a floating organic droplet and dispersive liquid– liquid microextraction based on the solidification of a floating organic droplet – for OTC extraction have been investigated. Extraction conditions of the investigated techniques have been optimized and analytical characteristics (limits of detection, calibration curve linear ranges, repeatabilities) have been determined. Dispersive liquid-liquid microextraction resulted to be the most suitable technique for real samples analysis. This technique has been applied for the analysis of river water samples. It was determined that the water from six rivers of Lithuania did not contain OTC or that the concentrations of OTC were below the limits of detection. |
