From polyethylene waste bottles to UIO-66 (Zr) for preconcentration of steroid hormones from river water

Abstract

Metal–organic framework (UiO-66 (Zr) was synthesized using polyethylene terephthalate (PET) and used as an adsorbent for extraction and preconcentration of steroid hormones in river water. Polyethylene waste bottles were used as the source of polyethylene terephthalate (PET) ligands. The UIO-66(Zr), which the PET was made from recycled waste plastics, was used for the first time for the extraction and preconcentration of four different types of steroid hormones in river water samples. Various analytical characterization techniques were employed to characterize the synthesized material. The steroid hormones were detected and quantified using high-performance liquid chromatography coupled with diode array detector (HPLC–DAD). The results were further validated using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Experimental variables, such as sample pH, the mass of adsorbent and extraction time, were optimized using Box-Behnken design (BBD). The dispersive solid phase extraction method combined with HPLC–DAD, displayed good linearity (0.004–1000 µg/L) low limits of detections (LODs, 1.1–16 ng/L for ultrapure water and 2.6–5.3 ng/L for river water) and limits of quantification (LOQs, 3.7–5.3 ng/L for ultrapure water and 8.7–11.0 ng/L for river water samples) and acceptable extraction recoveries (86–101%). The intraday (n = 10) and interday (n = 5) precisions expressed in terms of relative standard deviations (%RSD) were all less than 5%. The steroid hormones were detected in most of the river water samples (Vaal River and Rietspruit River). The DSPE/HPLC method offered a promising approach for simultaneous extraction, preconcentration and determination of steroid hormones in water.

Solvent Bar Microextraction Method Based on a Natural Deep Eutectic Solvent and Multivariate Optimization for Determination of Steroid Hormones in Urine and Water

“…As demonstrated in Figure 5, the efficiency of the SBME method was dependent on pH, and the optimum was reached at 7. However, a decrease in analytical signal was observed above and below pH 7 due to the hydrolysis of selected hormones [36,37]. Thus, pH 7 was selected as the best sample solution pH for further optimization steps.…”