Coacervative microextraction with solidification of floating surfactant droplets for the determination of glibenclamide in environmental water samples

Abstract

A green coacervative microextraction method with solidification of floating surfactant droplets (CAME-SFD) has been developed for the preconcentration and determination of glibenclamide in environmental water samples followed by fluorescence detection. The microextraction was performed by mixing the sample with SDS in a strong acidic medium. Then, the resulting solution was heated in a water bath at 100 °C for 23 min. After this, the tube was placed in an ice bath, and the surfactant rich phase was removed and dissolved with 500 µL of ethanol to perform the fluorometric measurements. A Plackett-Burman design was built to evaluate the main factors affecting the extraction, and the optimum values for the different factors were as follows: 5.0 mL of HCl 36.5–38.0% w/w (1.2 mol L−1), 800 µL of a 0.8 mol L−1 SDS solution, 500 mg of NaCl and 800 µL of MeOH. Under optimal conditions, the preconcentration factor was 86. The method presented a suitable liner range (0.50–4.20 µg L−1), a low limit of detection (0.37 µg L−1), and low RSD values (1.0–3.4%). The method was successfully applied to analyze surface water samples from the city of Bahía Blanca and Carmen de Patagones (Argentina), obtaining satisfactory recovery values (92.6–103.1%).