Methyl-tertiary-butyl ether (MTBE), an additive used to oxygenate gasoline, has been detected in lakes in northwestern New Jersey. This occurrence has been attributed to the use of gasoline-powered watercraft. This paper documents and explains both seasonal and daily variations in MTBE concentrations at Cranberry Lake. During a recent boating season (late April to September 1999), concentrations of MTBE typically exceeded 20 microg/L. MTBE concentrations varied daily from 12 to 24 microg/L over a 2-week period that included the Labor Day holiday. Concentrations were highest on weekends when there is more boat traffic, which had an immediate effect on MTBE mass throughout the lake. MTBE concentrations decreased to about 2 microg/L shortly after the end of the summer recreational season. The loss of MTBE can be accounted for by volatilization, with a half-life on the order of 10 days. The volatilization rate was modeled with the daily decrease in MTBE then the modeled rate was validated using the data from the seasonal decline.
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http://dx.doi.org/10.1016/S0043-1354(03)00243-4 | DOI Listing |
ACS Omega
January 2025
Groundwater Protection Unit, Environmental Department, Saudi Aramco, P.O. Box1977, Dhahran 31311, Saudi Arabia.
Methyl tertiary-butyl ether (MTBE) and BTEX (benzene, toluene, ethylbenzene, and xylenes) are common groundwater contaminants that pose significant health risks. This study investigated the efficiency of a colloidal activated carbon (CAC) material in removing MTBE and BTEX from contaminated water using batch and continuous core flooding systems. In the batch system, a mixture of sand and carbonate was coated with 1-3 g of CAC for the removal of contaminants.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
December 2024
Department of Clinical Diagnostics, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands. Electronic address:
Introduction: High-dose systemic prednisolone is the cornerstone treatment of many autoimmune- and inflammatory diseases. Since prednisolone shows non-linear protein binding at higher serum concentrations, quantification of the unbound prednisolone concentration is important to understand prednisolone pharmacokinetics. We developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay to quantify protein-unbound prednisolone in serum.
View Article and Find Full Text PDFPharmacol Rep
December 2024
Department of Drug Chemistry, Pharmaceutical and Biomedical Analysis, Faculty of Pharmacy, Medical University of Warsaw, Banacha 1, Warsaw, 02-097, Poland.
Background: The benefits of pharmacotherapy with sirolimus (SIR) in pediatric transplant recipients are well established. Traditionally, whole blood samples have been used to measure SIR concentrations. Volumetric Absorptive Microsampling (VAMS) is an alternative sampling strategy suitable for Therapeutic Drug Monitoring (TDM).
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
October 2024
Department of Forensic Medicine and Toxicology, Faculty of Medicine, School of Health Sciences, University of Ioannina, University Campus, Ioannina 45500, Greece; University Hospital of Ioannina, Ioannina 45110, Greece. Electronic address:
Liquid chromatography coupled with mass spectrometry (LC-MS) has been tremendously used for screening purposes in forensic toxicology, because of their great adaptability and reasonable time/resource consumption. Herein, a fully validated method based on liquid-liquid extraction (LLE) in human whole blood, by a multiple reaction monitoring (MRM) analysis through LC-MS/MS, is described. The proposed method simultaneously detects 100 analytes (plus three deuterated internal standard compounds) belonging to many different classes, including drugs of abuse, prescription and over-the-counter drugs commonly involved in poisoning and medical malpractice cases in our territory, as well as certain new psychoactive substances (NPS) and toxic substances potentially associated with adverse effects.
View Article and Find Full Text PDFSci Total Environ
December 2024
Lyles School of Civil and Construction Engineering, Purdue University, West Lafayette, IN 47907, United States. Electronic address:
The increasing prevalence of hazardous chemical incidents in the United States necessitates the implementation of analytically robust, rapid, and reliable screening techniques for toxicant mixture analysis to understand short- and long-term health impacts of environmental exposures. A recent chemical disaster in East Palestine, Ohio has underscored the importance of thorough contamination assessment. On February 03, 2023, a Norfolk Southern train derailment prompted a chemical spill and fires.
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