Abstract
Background: Solid-phase microextraction (SPME) is a simple and rapid extraction method that was introduced by Pawliszyn. During the ages significant developments were made in fiber types in order to overcome the traditional SPME fibers limitations.
Objective: In this project, a new application of a solid sorbent was introduced for head-space SPME (HS-SPME) determination of phenolic compounds. In this sorbent, MWCNTs were covalently functionalized and were attached chemically to the PDMS by the sol-gel method. Moreover, ionic liquids were used as porogenic agents in order to increase the fiber porosity.
Method: HS-SPME mode was used for analytes determination. The most important affecting parameters on method’s efficiency were investigated and optimized.
Results: At the optimized conditions, linear ranges were from 0.002-200 ng mL-1 with limits of detection (LODs) from 0.0005 to 0.005 ng mL-1 and limits of quantitation (LOQs) between 0.002-0.02 ng mL-1. Two different relative standard deviations (RSDs) were defined and calculated at three different concentrations (0.05, 2 and 100 ng mL-1). The first RSDs were for one fiber (repeatability) that were from 4.6 up to 6.7%. The secondary RSDs were between different fibers (reproducibility) that were from 5.7 to 7.8%.
Conclusion: The prepared fiber showed high thermal stability (over than 320 °C) with good lifespan (more than 210 times). Eventually, the phenolic compounds were determined in the real urine samples with this method. According to our results, the proposed method showed acceptable relative recovery percentages between 90.7 to 102.1% for the spiked urine samples at 0.5 ng mL-1.
Keywords: Gas chromatography, solid-phase microextraction, carbon nanotube, ionic liquid, phenolic compounds, sol-gel technique.
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