Effect of spring runoff on 2,6-dichloro-1,4-benzoquinone formation during water treatment.

This study investigated the impacts of spring runoff on the formation of halobenzoquinones (HBQs) and their correlation with common water quality parameters (WQPs) and aromatic amino acids (AAs) in source water. Source water and treated water samples were collected at two drinking water treatment plants in 2021, 2022, and 2023. HBQs and aromatic AAs were analyzed using solid phase extraction with high performance liquid chromatography-tandem mass spectrometry methods.

HDPairFinder: A data processing platform for hydrogen/deuterium isotopic labeling-based nontargeted analysis of trace-level amino-containing chemicals in environmental water.

The combination of hydrogen/deuterium (H/D) formaldehyde-based isotopic methyl labeling with solid-phase extraction and high-performance liquid chromatography-high resolution mass spectrometry (HPLC-HRMS) is a powerful analytical solution for nontargeted analysis of trace-level amino-containing chemicals in water samples. Given the huge amount of chemical information generated in HPLC-HRMS analysis, identifying all possible H/D-labeled amino chemicals presents a significant challenge in data processing. To address this, we designed a streamlined data processing pipeline that can automatically extract H/D-labeled amino chemicals from the raw HPLC-HRMS data with high accuracy and efficiency.

Amino Acids as Potential Precursors to Odorous Compounds in Tap Water during Spring Runoff Events.

The onset of spring runoff in northern climates and tap water odor events are difficult to predict because common water quality parameters cannot fully explain the intermittent odor events that occurred over past decades. Studies have shown that small polar water-soluble compounds, such as amino acids (AAs), leach first from ice/snowmelt. AAs are known to produce odorous compounds, such as aldehydes and chloroaldimines, upon chlorination.

Aspartame-Sweetened Tap Water: Transformation Products and 2,6-Dichloro-1,4-Benzoquinone Formation.

Aspartame (APM), a dipeptide of aspartic acid (ASP) and phenylalanine (PHE), is a widely used artificial sweetener in beverages. It is unclear whether residual chlorine in tap water can react with APM to form disinfection byproducts (DBPs). Therefore, we investigated the formation of DBPs from the reaction of APM with residual chlorine in authentic tap water.

Unique On-Site Spinning Sampling of Highly Water-Soluble Organics Using Functionalized Monolithic Sorbents.

Water utilities encounter unpredictable odor issues that cannot be explained by routine water parameters during spring runoff, even in the summer and fall. Highly water-soluble organics (, amino acids and saccharides) have been reported to form odorous disinfection byproducts during disinfection, but the lack of simple and practical on-site sampling techniques hampers their routine monitoring at trace levels in source water. Therefore, we have created two functionalized nested-in-sponge silica monoliths (NiS-SMs) using a one-pot synthesis method and demonstrated their application for extracting highly soluble organics in water.

Determination of eighty-two pesticides and application to screening pesticides in cannabis growing facilities.

Determination of pesticides in cannabis facilities is increasingly important as medicinal and recreational uses of cannabis products expand rapidly. We report a method involving wipe sampling, liquid chromatography separation, and tandem mass spectrometry, which enables determination of 82 pesticides out of the 96 regulated by Health Canada. To demonstrate an application of the method, we sampled and measured pesticides in two cannabis growing facilities, representing a non-certified and a certified site.

Nontargeted Identification of an -Heterocyclic Compound in Source Water and Wastewater as a Precursor of Multiple Nitrosamines.

-Nitrosamine disinfection byproducts (DBPs) are a health concern because they are probable human carcinogens. Complex organic nitrogenous compounds, nitrosamine precursors, are largely unidentified in source water. Using stable isotopic labeling-enhanced nontargeted analysis, we identified a natural product -heterocyclic amine 1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCCA) in source water.

New methods for identification of disinfection byproducts of toxicological relevance: Progress and future directions.

Disinfection byproducts (DBPs) represent a ubiquitous source of chemical exposure in disinfected water. While over 700 DBPs have been identified, the drivers of toxicity remain poorly understood. Additionally, ever evolving water treatment practices have led to a continually growing list of DBPs.

Stable Isotopic Labeling and Nontarget Identification of Nanogram/Liter Amino Contaminants in Water.

We report a new combinatorial approach of stable isotopic labeling (SIL)-solid phase extraction (SPE)-liquid chromatography-tandem high-resolution mass spectrometry (LC-HRMS/MS) for identification of amino-containing contaminants at trace levels in source water. The new SIL method requires small amounts of formaldehyde (CHO) and deuterated formaldehyde (CDO) to efficiently label ng/L amino compounds in 1 L of water and improves SPE recovery, enabling environmental analysis of trace amino-compounds. Isotopically methylated components were confirmed using LC-MS/MS based on their retention times, and characteristic isotope patterns of the molecular and product ions.

Pesticides and trace elements in cannabis: Analytical and environmental challenges and opportunities.

Cannabis is increasingly used for both medicinal and recreational purposes with an estimate of over 180 million users annually. Canada has recently legalized cannabis use in October 2018, joining several states in the United States of America (e.g.

Effect of nature of electrolytes on retention and selectivity in hydrophilic interaction liquid chromatography.

This work investigates the selectivity and retention changes on four classes of HILIC columns upon addition of 1-20 mM electrolyte. The effect of four electrolytes (NaCl, NaClO, NaPF, and NaCFCO) were tested on neutral, cationic, anionic, and zwitterionic analytes under HILIC conditions (70-90% ACN). These electrolytes alter the retention and selectivity on silica, zwitterionic and diol columns through ion exchange and ionic screening mechanisms.