Emerging micropollutants determination by NIR spectroscopy using pseudo-univariate calibration and TF-SPME coupled with 96-well plate system

Abstract

In this study, an innovative approach was developed to determine simultaneously the emerging micropollutants bisphenol A (BPA), 3-(4-methylbenzylidene) camphor (4-MBC), triclocarban (TCC), benzophenone (BZP) and 2-ethyl-hexyl-4-trimethoxycinnamate (EHMC) in water employing near infrared spectroscopy (NIR) coupled with thin film solid-phase microextraction (TF-SPME) using the chemometric tool of multivariate curve resolution with alternating least squares (MCR-ALS). In addition, a 96-well plate system was employed to increase the analysis throughput of the proposed methodology. Samples were submitted to TF-SPME procedure (previously optimized in previous work to exhibit the best performance for extraction and desorption conditions) and its extracts were analyzed by NIR. A pseudo-univariate calibration model for each analyte was developed by associating the relative concentration obtained using MCR-ALS with the reference concentration (i.e. theoretical concentration). The correlation coefficients obtained were 0.9238, 0.8722, 0.7872, 0.8856 and 0.9128 for BPA, 4-MBC, TCC, BZP and EHMC, respectively. With the use of these pseudo-univariate models, the determination of the analytes exhibited absolute errors lowers than those of the chromatographic technique for BZP and TCC. For BPA, 4-MBC and EHMC the absolute error was lower than 10 µg L − 1. This approach can provide a cheap and rapid strategy for the direct quantification of these micropollutants in water samples.