The lipophilicities of 22 selected sunscreens, preservatives, and vitamins used in topical skin products were measured by thin-layer chromatography. Lipophilicity was calculated in silico from the sunscreen molecular structures and compared to the experimental octanol/water partition coefficients found in the literature. The retention of the compounds was investigated on an RP-18 stationary phase with mobile phases consisting of water and one of six organic modifiers (dioxane, tetrahydrofuran, acetone, acetonitrile, methanol, and dimethylformamide) at different concentrations. The theoretical lipophilicities were calculated by several computational algorithms and the results of these calculations were compared using cluster analysis. The results showed that two out of the six investigated organic modifiers (dioxane and acetone) may be used to estimate the octanol/water partition coefficients of highly lipophilic compounds having lipophilicities that cannot be measured directly by the shake-flask method.
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http://dx.doi.org/10.1002/jssc.201400535 | DOI Listing |
Sci Total Environ
January 2025
Centro de Genómica, Ecología y Medio Ambiente (GEMA), Universidad Mayor, Campus Huechuraba, Santiago, Chile; Institute of Environment, Florida International University, University Park, Miami, FL 33199, USA; Data Observatory Foundation, Santiago, Chile. Electronic address:
Semi-volatile organic compounds (SVOCs) are widely distributed across the globe, including polar regions. This study investigates the distribution and bioconcentration of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) in soils and Colobanthus quitensis, while also estimating potential emission sources. Results indicated high concentrations of PAHs in soils and plants from the Sub-Antarctic region, while OCPs and PCBs were more prevalent in the Antarctic region, with higher contaminant concentrations found in soils than in plant tissues.
View Article and Find Full Text PDFEnviron Pollut
January 2025
School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China. Electronic address:
The soils/sediments organic carbon sorption coefficient (K) of organic substances is one of the indispensable environmental behavioral parameters in chemicals management. Because the test procedure used to measure K is normally expensive and time-consuming, predictive methods are considered vitally important technology to fill the data gap of K. In this study, quantitative structure-property relationship (QSPR) models are developed using a data set with 1477 experimental logK values and seven typical machine learning algorithms.
View Article and Find Full Text PDFEnviron Pollut
January 2025
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
Despite the significant benefits of aquatic passive sampling (low detection limits and time-weighted average concentrations), the use of passive samplers is impeded by uncertainties, particularly concerning the accuracy of sampling rates. This study employed a systematic evaluation approach based on the combination of meta-analysis and quantitative structure-property relationships (QSPR) models to address these issues. A comprehensive meta-analysis based on extensive data from 298 studies on the Polar Organic Chemical Integrative Sampler (POCIS) identified essential configuration parameters, including the receiving phase (type, mass) and the diffusion-limiting membrane (type, thickness, pore size), as key factors influencing uptake kinetic parameters.
View Article and Find Full Text PDFLangmuir
January 2025
Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
Inclusion complexation of the sunscreen ingredient avobenzone (AVB) with β-cyclodextrin (β-CD) was investigated to improve its aqueous solubility and photostability; another ultraviolet (UV) filter, oxybenzone (OXB), and the phytochemical antioxidant curcumin (CUR) served as a comparison. In this study, the 1-octanol/water partition coefficients, acid dissociation constants, phase-solubility diagrams with β-CD, and ultraviolet-visible (UV-vis) spectral changes induced by UVA1 (365 nm) irradiation were evaluated. β-CD at concentrations 50-100 times that of AVB most effectively protected the photostability of AVB.
View Article and Find Full Text PDFNatl Sci Rev
January 2025
Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China.
The high thermopower of ionic thermoelectric (-TE) materials holds promise for miniaturized waste-heat recovery devices and thermal sensors. However, progress is hampered by laborious trial-and-error experimentations, which lack theoretical underpinning. Herein, by introducing the simplified molecular-input line-entry system, we have addressed the challenge posed by the inconsistency of -TE material types, and present a machine learning model that evaluates the Seebeck coefficient with an of 0.
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