Category: 620-92-8

Validated single urinary assay designed for exposomic multi-class biomarkers of common environmental exposures was written by Jagani, Ravikumar;Pulivarthi, Divya;Patel, Dhavalkumar;Wright, Rosalind J.;Wright, Robert O.;Arora, Manish;Wolff, Mary S.;Andra, Syam S.. And the article was included in Analytical and Bioanalytical Chemistry in 2022.Reference of 620-92-8 The following contents are mentioned in the article:

Epidemiol. studies often call for anal. methods that use a small biospecimen volume to quantify trace level exposures to environmental chem. mixtures Currently, as many as 150 polar metabolites of environmental chems. have been found in urine. Therefore, we developed a multi-class method for quantitation of biomarkers in urine. A single sample preparation followed by three LC injections was optimized in a proof-of-approach for a multi-class method. The assay was validated to quantify 50 biomarkers of exposure in urine, belonging to 7 chem. classes and 16 sub-classes. The classes represent metabolites of 12 personal care and consumer product chems. (PCPs), 5 polycyclic aromatic hydrocarbons (PAHs), 5 organophosphate flame retardants (OPFRs), 18 pesticides, 5 volatile organic compounds (VOCs), 4 tobacco alkaloids, and 1 drug of abuse. Human urine (0.2 mL) was spiked with isotope-labeled internal standards, enzymically deconjugated, extracted by solid-phase extraction, and analyzed using high-performance liquid chromatog.-tandem mass spectrometry. The methanol eluate from the cleanup was split in half and the first half analyzed for PCPs, PAH, and OPFR on a Betasil C18 column; and pesticides and VOC on a Hypersil Gold AQ column. The second half was analyzed for tobacco smoke metabolites and a drug of abuse on a Synergi Polar RP column. Limits of detection ranged from 0.01 to 1.0 ng/mL of urine, with the majority ≤0.5 ng/mL (42/50). Anal. precision, estimated as relative standard deviation of intra- and inter-batch uncertainty, variabilities, was <20%. Extraction recoveries ranged from 83 to 109%. Results from the optimized multi-class method were qualified in formal international proficiency testing programs. Further method customization options were explored and method expansion was demonstrated by inclusion of up to 101 analytes of endo- and exogenous chems. This exposome-scale assay is being used for population studies with savings of assay costs and biospecimens, providing both quant. results and the discovery of unexpected exposures. This study involved multiple reactions and reactants, such as 4,4′-Methylenediphenol (cas: 620-92-8Reference of 620-92-8).

4,4′-Methylenediphenol (cas: 620-92-8) belongs to alcohols. Similar to water, an alcohol can be pictured as having an sp3 hybridized tetrahedral oxygen atom with nonbonding pairs of electrons occupying two of the four sp3 hybrid orbitals. Alcohols may be oxidized to give ketones, aldehydes, and carboxylic acids. These functional groups are useful for further reactions. Oxidation of organic compounds generally increases the number of bonds from carbon to oxygen (or another electronegative element, such as a halogen), and it may decrease the number of bonds to hydrogen.Reference of 620-92-8

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Enhanced Toxicity of Bisphenols Together with UV Filters in Water: Identification of Synergy and Antagonism in Three-Component Mixtures was written by Kudlak, Blazej;Jatkowska, Natalia;Liu, Wen;Williams, Michael J.;Barcelo, Damia;Schioth, Helgi B.. And the article was included in Molecules in 2022.Recommanded Product: 620-92-8 The following contents are mentioned in the article:

Contaminants of emerging concern (CEC) localize in the biome in variable combinations of complex mixtures that are often environmentally persistent, bioaccumulate and biomagnify, prompting a need for extensive monitoring. Many cosmetics include UV filters that are listed as CECs, such as benzophenone derivatives (oxybenzone, OXYB), cinnamates (2-ethylhexyl 4-methoxycinnamate, EMC) and camphor derivatives (4-methylbenzylidene-camphor, 4MBC). Furthermore, in numerous water sources, these UV filters have been detected together with Bisphenols (BPs), which are commonly used in plastics and can be physiol. detrimental. We utilized bioluminescent bacteria (Microtox assay) to monitor these CEC mixtures at environmentally relevant doses, and performed the first systematic study involving three sunscreen components (OXYB, 4MBC and EMC) and three BPs (BPA, BPS or BPF). Moreover, a breast cell line and cell viability assay were employed to determine the possible effect of these mixtures on human cells. Toxicity modeling, with concentration addition (CA) and independent action (IA) approaches, was performed, followed by data interpretation using Model Deviation Ratio (MDR) evaluation. The results show that UV filter sunscreen constituents and BPs interact at environmentally relevant concentrations Of notable interest, mixtures containing any pair of three BPs (e.g., BPA + BPS, BPA + BPF and BPS + BPF), together with one sunscreen component (OXYB, 4MBC or EMC), showed strong synergy or overadditive effects. On the other hand, mixtures containing two UV filters (any pair of OXYB, 4MBC and EMC) and one BP (BPA, BPS or BPF) had a strong propensity towards concentration dependent underestimation. The three-component mixtures of UV filters (4MBC, EMC and OXYB) acted in an antagonistic manner toward each other, which was confirmed using a human cell line model. This study is one of the most comprehensive involving sunscreen constituents and BPs in complex mixtures, and provides new insights into potentially important interactions between these compounds This study involved multiple reactions and reactants, such as 4,4′-Methylenediphenol (cas: 620-92-8Recommanded Product: 620-92-8).

4,4′-Methylenediphenol (cas: 620-92-8) belongs to alcohols. Similar to water, an alcohol can be pictured as having an sp3 hybridized tetrahedral oxygen atom with nonbonding pairs of electrons occupying two of the four sp3 hybrid orbitals. A multistep synthesis may use Grignard-like reactions to form an alcohol with the desired carbon structure, followed by reactions to convert the hydroxyl group of the alcohol to the desired functionality.Recommanded Product: 620-92-8

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Urinary levels of parabens, phthalate metabolites, bisphenol A and plasticizer alternatives in a Belgian population: Time trend or impact of an awareness campaign? was written by Pirard, Catherine;Charlier, Corinne. And the article was included in Environmental Research in 2022.Quality Control of 4,4′-Methylenediphenol The following contents are mentioned in the article:

A human biomonitoring study was carried out in 2015 within an adult population living in Liege (Belgium). Some phthalate metabolites and parabens were measured in the urine of 252 participants, and information were collected about their food habits, life styles and home environment to identify some predictors of exposure. Concomitantly, an awareness campaign was initiated by the Provincial Authorities of Liege and spread over 2 years. Three years later (2018), 92 of the initial participants provided again urine samples, and the levels of phthalate metabolites, phthalate substitute (DINCH), parabens, bisphenol-A and bisphenol alternatives (bisphenol-S, -F, -Z, -P) were determined and compared to those obtained in 2015 to assess time trends. In 2015, methyl- and ethylparaben were the most abundant parabens (P50 = 9.12 μg/L and 1.1 μg/L resp.), while propyl- and butylparaben were sparsely detected. Except for mono-2-ethylhexyl phthalate and 6-OH-mono-propyl-heptyl phthalate, all other targeted phthalate metabolites were pos. quantified in most of the urine samples (between 89 and 98%) with median concentrations ranging between 2.7 μg/L and 21.3 μg/L depending on the metabolite. The multivariate regression models highlighted some significant associations between urinary phthalate metabolite or paraben levels and age, rural or urban character of the residence place, and the use of some personal care products. However, all determination coefficients were weak meaning that the usual covariates included in the models only explained a small part of the variance. Between 2015 and 2018, levels of parabens and phthalate metabolites significantly decreased (from 1.3 to 2.5 fold) except for monoethyl phthalate which seemed to remain quite constant Contrariwise, all bisphenol alternatives and DINCH metabolites were measured in higher concentrations in 2018 vs 2015 while BPA levels did not differ significantly. However, it was not feasible to unequivocally highlight an impact of the awareness campaign on the exposure levels of the population. This study involved multiple reactions and reactants, such as 4,4′-Methylenediphenol (cas: 620-92-8Quality Control of 4,4′-Methylenediphenol).

4,4′-Methylenediphenol (cas: 620-92-8) belongs to alcohols. Under appropriate conditions, inorganic acids also react with alcohols to form esters. To form these esters, a wide variety of specialized reagents and conditions can be used. Converting an alcohol to an alkene requires removal of the hydroxyl group and a hydrogen atom on the neighbouring carbon atom. Dehydrations are most commonly carried out by warming the alcohol in the presence of a strong dehydrating acid, such as concentrated sulfuric acid.Quality Control of 4,4′-Methylenediphenol

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Magnetic porous cellulose surface-imprinted polymers synthetized with assistance of deep eutectic solvent for specific recognition and purification of bisphenols was written by Wen, Zeng;Gao, Die;Lin, Jing;Li, Siyi;Zhang, Kailian;Xia, Zhining;Wang, Dandan. And the article was included in International Journal of Biological Macromolecules in 2022.HPLC of Formula: 620-92-8 The following contents are mentioned in the article:

Magnetic porous cellulose molecularly imprinted polymers-based bisphenols have been developed using Fe₃O₄ as the magnetic material, a deep eutectic solvent as the assisted solvent, and N-isopropylacrylamide as the functional monomer. The resulting magnetic porous cellulose molecularly imprinted polymers were characterized using SEM, Fourier transform IR spectroscopy, X-ray diffraction, vibrating sample magnetometry, thermal gravimetric anal., and Brunauer-Emmett-Teller anal. Moreover, the adsorption properties of the magnetic porous cellulose molecularly imprinted polymers toward bisphenol A, bisphenol F, and bisphenol AF were investigated using static, dynamic, and selective adsorption experiments The introduction of porous cellulose materials significantly improves the capabilities of the material. The adsorption capacity, mass transfer efficiency, and selectivity of the magnetic porous cellulose molecularly imprinted polymers toward bisphenol A were 5.9, 4.0, and 4.4 times those of traditional molecularly imprinted polymers. Moreover, the adsorption stability of the magnetic porous cellulose molecularly imprinted polymers was investigated under different temperature and pH conditions. The adsorption characteristics of the magnetic porous cellulose molecularly imprinted polymers toward the target mols. were investigated using adsorption isotherm, kinetic, and thermodn. models. Hydrogen bonding is the main interaction formed between the magnetic porous cellulose molecularly imprinted polymers and the target mols. Magnetic porous cellulose molecularly imprinted polymers have great application value with excellent stability and reusability. Finally, the combination of the magnetic porous cellulose molecularly imprinted polymers and high-performance liquid chromatog. or ultra-performance liquid chromatog.-mass spectrometry was successfully used for the purification and detection of bisphenols in milk (1.349 ng/mL bisphenol F and 3.014 ng/mL bisphenol AF), canned fruits (1129 ng/mL bisphenol A, 10.11 ng/mL bisphenol F, and 91.87 ng/mL bisphenol AF), and fish (11.91 ng/mL bisphenol AF) samples. Furthermore, the magnetic porous cellulose molecularly imprinted polymer method is more selective, sensitive, and accurate than the traditional precipitation method. This study involved multiple reactions and reactants, such as 4,4′-Methylenediphenol (cas: 620-92-8HPLC of Formula: 620-92-8).

4,4′-Methylenediphenol (cas: 620-92-8) belongs to alcohols. Because alcohols are easily synthesized and easily transformed into other compounds, they serve as important intermediates in organic synthesis. Alcohols may be oxidized to give ketones, aldehydes, and carboxylic acids. These functional groups are useful for further reactions. Oxidation of organic compounds generally increases the number of bonds from carbon to oxygen (or another electronegative element, such as a halogen), and it may decrease the number of bonds to hydrogen.HPLC of Formula: 620-92-8

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

A decade of monitoring micropollutants in urban wet-weather flows: What did we learn? was written by Mutzner, Lena;Furrer, Viviane;Castebrunet, Helene;Dittmer, Ulrich;Fuchs, Stephan;Gernjak, Wolfgang;Gromaire, Marie-Christine;Matzinger, Andreas;Mikkelsen, Peter Steen;Selbig, William R.;Vezzaro, Luca. And the article was included in Water Research in 2022.Product Details of 620-92-8 The following contents are mentioned in the article:

Urban wet-weather discharges from combined sewer overflows (CSO) and stormwater outlets (SWO) are a potential pathway for micropollutants (trace contaminants) to surface waters, posing a threat to the environment and possible water reuse applications. Despite large efforts to monitor micropollutants in the last decade, the gained information is still limited and scattered. In a metastudy we performed a data-driven anal. of measurements collected at 77 sites (683 events, 297 detected micropollutants) over the last decade to investigate which micropollutants are most relevant in terms of (1) occurrence and (2) potential risk for the aquatic environment, (3) estimate the min. number of data to be collected in monitoring studies to reliably obtain concentration estimates, and (4) provide recommendations for future monitoring campaigns. We highlight micropollutants to be prioritized due to their high occurrence and critical concentration levels compared to environmental quality standards These top-listed micropollutants include contaminants from all chem. classes (pesticides, heavy metals, polycyclic aromatic hydrocarbons, personal care products, pharmaceuticals, and industrial and household chems.). Anal. of over 30,000 event mean concentrations shows a large fraction of measurements (> 50%) were below the limit of quantification, stressing the need for reliable, standard monitoring procedures. High variability was observed among events and sites, with differences between micropollutant classes. The number of events required for a reliable estimate of site mean concentrations (error bandwidth of 1 around the “true” value) depends on the individual micropollutant. The median min. number of events is 7 for CSO (2 to 31, 80%-interquantile) and 6 for SWO (1 to 25 events, 80%-interquantile). Our anal. indicates the min. number of sites needed to assess global pollution levels and our data collection and anal. can be used to estimate the required number of sites for an urban catchment. Our data-driven anal. demonstrates how future wet-weather monitoring programs will be more effective if the consequences of high variability inherent in urban wet-weather discharges are considered. This study involved multiple reactions and reactants, such as 4,4′-Methylenediphenol (cas: 620-92-8Product Details of 620-92-8).

4,4′-Methylenediphenol (cas: 620-92-8) belongs to alcohols. Under appropriate conditions, inorganic acids also react with alcohols to form esters. To form these esters, a wide variety of specialized reagents and conditions can be used. Alcohols may be oxidized to give ketones, aldehydes, and carboxylic acids. These functional groups are useful for further reactions. Oxidation of organic compounds generally increases the number of bonds from carbon to oxygen (or another electronegative element, such as a halogen), and it may decrease the number of bonds to hydrogen.Product Details of 620-92-8

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Study of flame retardancy effect on the thermal degradation of a new green biocomposite and estimation of lower flammability limits of the gaseous emissions was written by Rashid, M.;Chetehouna, K.;Lemee, L.;Roudaut, C.;Gascoin, N.. And the article was included in Journal of Thermal Analysis and Calorimetry in 2022.Quality Control of 4,4′-Methylenediphenol The following contents are mentioned in the article:

Green biocomposites (GBCs) decompose and release significant amount of gases under high temperature that poses self-ignition risk and contribute to the growth of fire. Thermal characterization of green biocomposite is therefore an essential task to assess the characteristics of the material to approve its use at the industrial scale. In this context, research work has been carried out to evaluate thermal decomposition patterns of the material, to record the volatile emissions and to estimate the self-ignition risk so that the newly developed green biocomposite can be standardised based on the fire safety standards of marine, automotive and aeronautical industry. This research endeavour focuses on the thermal characterization of a newly developed green biocomposite for the evaluation of thermal stability, identification of gaseous emission and calculation of lower flammability limit (LFL). Intumescent fire-retardant coating composed of ammonium polyphosphate-tris(2-hydroxyethyl)isocyanurate (APP-THEIC) and boric acid (BA) was coated on a GBC that is composed of 38% bioepoxy and flax fiber to improve thermal profile of the material. The thermal stability of the newly developed material was evaluated using thermogravimetric anal. (TGA). An anal. pyrolyzer coupled with gas chromatograph and mass spectrometer (Py-GC-MS) was used at four selected temperatures, i.e. 350, 550, 750 and 900°C, to record the gaseous emissions from GBC. The evolved species during pyrolysis were identified on the pyrograms, and their lower flammability limit was determined using quant. structure-property relationship (QSPR). The hazards of the new materials for emergency response were identification using NFPA 704. In this study, the GBC developed was characterised based on its thermal decomposition profile, degradation temperature, gaseous emissions and lower flammability limit. It was observed on the TG curves that the green biocomposite fully degrades at approx. 600°C. The application of intumescent fire-retardant (IFR) coating improves the fire retardancy of the material, and final degradation temperature of the material reaches approx. 800°C. The newly developed green biocomposite needs to be tested under medium-scale tests to reach a conclusion about its thermal degradation profile. The QSPR study of the gaseous emissions evolved from the pyrolysis of green biocomposite reveals that the LFL decreases as the temperature is increased up to 750°C. Based on the toxicity anal. of the gaseous emission, the material releases high amount of phenol above 350°C, which is hazardous for health if inhaled. This study involved multiple reactions and reactants, such as 4,4′-Methylenediphenol (cas: 620-92-8Quality Control of 4,4′-Methylenediphenol).

4,4′-Methylenediphenol (cas: 620-92-8) belongs to alcohols. Under appropriate conditions, inorganic acids also react with alcohols to form esters. To form these esters, a wide variety of specialized reagents and conditions can be used. A multistep synthesis may use Grignard-like reactions to form an alcohol with the desired carbon structure, followed by reactions to convert the hydroxyl group of the alcohol to the desired functionality.Quality Control of 4,4′-Methylenediphenol

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts