Epoxy resin as a new alternative sorbent phase for stir bar sorptive extraction for the determination of triclosan and methyl-triclosan.

The main objective of this study is to propose a new sorbent phase based on a commercial epoxy resin, for use as an alternative sorbent in the stir bar sorptive extraction (SBSE) technique. The analytes triclosan (TCS) and methyl-triclosan (MTCS) were selected in order to demonstrate the application of the bars, using some water samples as matrices. The extraction conditions of sample volume, stirring time, pH, temperature and ionic strength were evaluated, and for the back extraction, the bars were sonicated using 1.00 mL of acetonitrile for 10 min. The technique of liquid chromatography using a diode array detector was employed for the quantitation. Analytical curves of between 2.50 and 50.0 μg L-1 with r2 of 0.9894 (TCS) and 0.9933 (MTCS), and limit of detection (LOD) values of 0.6 μg L-1 (TCS) and 2.0 μg L-1 (MTCS) were observed. Recovery values between 100.4% and 121.6% were verified for ultrapure water and between 50.3% and 93.8% for wastewater samples, thereby suggesting the possibility of employing the bars for quantitation of TCS and MTCS in aqueous samples. This is the first time that this resin has been applied without the need for the adhesion of any additional sorbent phase, thereby providing a simple and low-cost method. Another feature is that only eight bars were employed in the entire work, and each bar was used approximately 40 times with the same performance without memory effects.