Near real-time monitoring of the Biscayne Bay Watershed (South Florida, USA) and major tributaries by water quality research buoys.

Biscayne Bay (South Florida) is a subtropical estuary that requires freshwater inputs to maintain its ecological balance. Over the past 50+ years, the bay has been disrupted by contaminated freshwater released from tributaries and canals, negatively affecting its water quality. Specific areas of the bay have been recognized as impaired with respect to nutrients, chlorophyll and bacterial contamination.

Investigating the chemical space coverage of multiple chromatographic and ionization methods using non-targeted analysis on surface and drinking water collected using passive sampling.

Multiple non-targeted analysis tools were used to look for a broad range of possible chemical contaminants present in surface and drinking water using liquid chromatography separation and high-resolution mass spectrometry detection, including both quadrupole time of flight (Q-ToF) and Orbitrap instruments. Two chromatographic techniques were evaluated on an LC-Q-ToF with electrospray ionization in both positive and negative modes: (1) the traditionally used reverse phase C18 and (2) the hydrophilic interaction liquid chromatography (HILIC) aimed to capture more polar contaminants that may be present in water. Multiple ionization modes were evaluated with an LC-Orbitrap, including electrospray (ESI) and atmospheric pressure chemical ionization (APCI), also in both positive and negative modes.

Prevalence of selected UV filter compounds in Biscayne National Park.

This research was carried out in order to assess a baseline occurrence in Biscayne National Park, Florida, of four organic contaminants: the UV filters oxybenzone, dioxybenzone, and benzophenone, as well as the topical pain reliever benzocaine. A total of 35 samples were taken from five locations within the park, four near barrier islands, and one at a coral reef. Analyses were carried out using liquid chromatography coupled to high-resolution mass spectrometry.

Innovative non-targeted screening approach using High-resolution mass spectrometry for the screening of organic chemicals and identification of specific tracers of soil and dust exposure in children.

Environmental contamination through direct contact, ingestion and inhalation are common routes of children's exposure to chemicals, in which through indoor and outdoor activities associated with common hand-to-mouth, touching objects, and behavioral tendencies, children can be susceptible and vulnerable to organic contaminants in the environment. The objectives of this study were the screening and identification of a wide range of organic contaminants in indoor dust, soil, food, drinking water, and urine matrices (N = 439), prioritizing chemicals to assess children's environmental exposure, and selection of unique tracers of soil and dust ingestion in young children by non-targeted analysis (NTA) using Q-Exactive Orbitrap followed data processing by the Compound Discoverer (v3.3, SP2).

Unraveling the chemical fingerprint of the Miami River sources: Insights from high-resolution mass spectrometry and nontarget analysis.

This study investigated the chemical composition of waters in the heavily urbanized and historically polluted Miami River, Florida. The goal was to assess the different water sources and anthropogenic influence in this managed area using nontarget analysis (NTA) combined with high-resolution mass spectrometry (HRMS). Surface water samples were collected from 10 sites during five sampling events in the wet season of 2021 and 2022.