Solid phase microextraction (SPME) of chlorophenols [2-chlorophenol (2CP), 2,4-dichlorophenol (24CP), 4-chloro-3-methylphenol (43CP), 2,4,6-tri-chlorophenol (246CP) and pentachlorophenol (PCP)] followed by direct mass spectrometric analysis has been performed by fiber introduction mass spectrometry (FIMS). Two SPME fibers (65 microm PDMS/DVB and 85 microm PA fibers) were tested, and FIMS was performed via selective ion monitoring (SIM). The extractions were evaluated at 10% ionic strength and pH 1. Best extraction times were determined for both fibers. Limits of detection (LOD) and limits of quantification (LOQ) for both fibers were in the low microg L(-1) range. Coefficients of correlation for the analytical curves showed linear responses and mineral water and river water samples spiked with 50 microg L(-1) presented high recoveries. FIMS, as compared to current EPA methods, is demonstrated to allow faster and simpler (elimination of pre-separation or derivatization steps) analysis of chlorophenols in water with the required sensitivity.
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http://dx.doi.org/10.1016/j.aca.2008.05.033 | DOI Listing |
BMC Med Res Methodol
December 2024
School of Mathematical & Statistical Sciences, University of Texas Rio Grande Valley, One West University Boulevard, Brownsville, TX, 78520, USA.
Background: Missing observations within the univariate time series are common in real-life and cause analytical problems in the flow of the analysis. Imputation of missing values is an inevitable step in every incomplete univariate time series. Most of the existing studies focus on comparing the distributions of imputed data.
View Article and Find Full Text PDFJ Environ Manage
December 2024
Environmental Engineering Division, Department of Civil Engineering, Indian Institute of Technology Madras, Chennai, Tamil Nadu, 600036, India. Electronic address:
The release of toxic chemical dyes from the industrial effluent poses huge challenges for the environmental engineers to treat it. Azo dyes encompass the huge part of textile discharges which are difficult to degrade due to their complex chemical aromatic structures and due to the presence of strong bonds (-N=N-). Thus, the removal of a carcinogenic azo dye (i.
View Article and Find Full Text PDFJ Infect Dev Ctries
November 2024
Department of Dermatology and Venereology, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia.
Introduction: Yaws remains a public health problem in Indonesia, and it is the largest contributor to Yaws cases in Southeast Asia. Yaws is caused by bacterial infection of Treponema pallidum subspecies pertenue, mainly affecting the skin and bones. An estimated 75% of new cases were found in children under 15.
View Article and Find Full Text PDFHeliyon
August 2024
School of Advanced Technologies, Shiraz University, Shiraz, Iran.
A reliable photovoltaic (PV) model with logical trade-off between accuracy and simplicity can be utilized for optimal design, monitoring, fault detection and prediction of operational power. In this research work, two novel datasheet-based approaches are developed for PV module identification through double-diode model (DDM). In both methods the four unknown parameters are derived as functions of series resistance ( ).
View Article and Find Full Text PDFJ Chem Theory Comput
December 2024
Centre for Computational Science, Department of Chemistry, University College London, London WC1H 0AJ, United Kingdom.
Free energy calculations for protein-ligand complexes have become widespread in recent years owing to several conceptual, methodological and technological advances. Central among these is the use of ensemble methods which permits accurate, precise and reproducible predictions and is necessary for uncertainty quantification. Absolute binding free energies (ABFEs) are challenging to predict using alchemical methods and their routine application in drug discovery has remained out of reach until now.
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