Polyamide-coated paper-based sorptive phase applied in high-throughput thin film microextraction designed by 3D printing

Abstract

A new method was developed for the determination of endocrine disrupting compounds (phthalates, alkylphenols and bisphenols) in water samples by using thin film microextraction technique (TFME) with high-performance liquid chromatography and diode-array detection (HPLC-DAD). This paper reports for the first time the use of a paper-based sorptive phase (PSP) in a high-throughput semi-automated system. This system designed by 3D printing technology allowed us to integrate the PSP with a multi-well plate format. Multivariate design of experiments and one-factor-at-a-time approaches were employed for optimization. The optimized PSP preparation required two dips of the filter paper into the nylon 66 solution followed by the evaporation of the solvent. The best conditions for the extraction step were NaCl 30 % (w/v) added to the sample at pH 2 for 180 min. The desorption showed best results with acetonitrile for 20 min. The calibration curves exhibited coefficients of determination higher than 0.9837. The limits of detection varied from 1.5 to 7.6 μg L-1. Six of ten analytes showed promising results with accuracy ranging from 82 to 117 % and precision (RSD) equal or inferior to 24 % for mineral water sample. We also evaluated a coconut water sample that obtained higher deviations than mineral water sample. The time consumed for each sample was about 8.3 min.