Passive in-situ estrogenic potency sampling with DGT-YES
type: CreativeWork
description: The purpose of this research was to investigate the presence of bisphenolic plastics and synthetic estrogens in municipal water systems, as well as along the Waikato River. The concentration of these compounds was assessed using a novel combination of methods that allowed the actual levels of endocrine disruption to be ascertained. This was based on diffusive gradients in thin films (DGTs) coupled with high-performance liquid chromatography/mass spectrometry analysis (HPLC/MS) and the Yeast Estrogen Screen (YES). DGT estimated time-integrated concentrations while HPLC/MS ensured a robust, automated and sensitive routine analysis. Most significantly, YES, a biomarker-based assay, was deployed to quantify the total estrogenic potency of the compounds adsorbed to the DGT matrix. The unique dimension of this research was to extend the application of DGTs to estrogen sampling and to combine the DGT and YES technique to provide in situ quantification of the estrogenic potency of water bodies through time. DGTs were developed specifically for the sampling of BPA, BPAF, E2 and EE2. Several physical-chemical and chemical analyses were conducted to attest the suitability of the agarose (1.5%) and agarose (1.5%) – activated charcoal (1%) chosen respectively as diffusive gel and binding gel. They were found to be suitable for the detection of organic molecules with a bigger steric hindrance and agarose (1.5%) – AC (1%) appeared suitable for long deployments thanks to its high thermal resistance. An HPLC-MS method was optimised to quantify the compounds of interest. A methanol (MeOH, NH4OH 0.06 M)/water (H2O, NH4OH 0.06 M) fast gradient elution program of 15 min was chosen to elute the analytes, MS parameters were optimized for each compound and the negative mode was selected to perform the fragmentation. LODs and LOQs of all targets resulted in the nanomolar range assuming 24 h as deployment time at 25°C with a 0.54 mm thick diffusive gel. The sensitivity of the method was incr…
abstract: The purpose of this research was to investigate the presence of bisphenolic plastics and synthetic estrogens in municipal water systems, as well as along the Waikato River. The concentration of these compounds was assessed using a novel combination of methods that allowed the actual levels of endocrine disruption to be ascertained. This was based on diffusive gradients in thin films (DGTs) coupled with high-performance liquid chromatography/mass spectrometry analysis (HPLC/MS) and the Yeast Estrogen Screen (YES). DGT estimated time-integrated concentrations while HPLC/MS ensured a robust, automated and sensitive routine analysis. Most significantly, YES, a biomarker-based assay, was deployed to quantify the total estrogenic potency of the compounds adsorbed to the DGT matrix. The unique dimension of this research was to extend the application of DGTs to estrogen sampling and to combine the DGT and YES technique to provide in situ quantification of the estrogenic potency of water bodies through time. DGTs were developed specifically for the sampling of BPA, BPAF, E2 and EE2. Several physical-chemical and chemical analyses were conducted to attest the suitability of the agarose (1.5%) and agarose (1.5%) – activated charcoal (1%) chosen respectively as diffusive gel and binding gel. They were found to be suitable for the detection of organic molecules with a bigger steric hindrance and agarose (1.5%) – AC (1%) appeared suitable for long deployments thanks to its high thermal resistance. An HPLC-MS method was optimised to quantify the compounds of interest. A methanol (MeOH, NH4OH 0.06 M)/water (H2O, NH4OH 0.06 M) fast gradient elution program of 15 min was chosen to elute the analytes, MS parameters were optimized for each compound and the negative mode was selected to perform the fragmentation. LODs and LOQs of all targets resulted in the nanomolar range assuming 24 h as deployment time at 25°C with a 0.54 mm thick diffusive gel. The sensitivity of the method was incr…
author: Iuele, Helena
license: https://researchcommons.waikato.ac.nz/bitstreams/372eecc7-9530-47cd-b092-f777fcdd26db/download
date published: 2019
date modified: 2026-07-24T05:57:18Z
provider: University Waikato
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: The University of Waikato