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Published in James G. Speight, Handbook of Petrochemical Processes, 2019
2-Naphthol is not a product that is isolated from crude oil more likely it is isolated from the products of the thermal decomposition of coal and some types of biomass. Traditionally, 2-naphthol is produced by a two-step process that begins with the sulfonation of naphthalene in sulfuric acid. The sulfonic acid group is then cleaved in molten sodium hydroxide: C10H8+H2SO4→C10H7SO3H+H2OC10H7(SO3H)+3NaOH→C10H7ONa+Na2SO3+2H2O
Synthesis of novel, coumarin-based, mosquito repellent-cum-multifunctional azo disperse dye for functional dyeing of polyester
Published in The Journal of The Textile Institute, 2023
11.89 mmol of 4-hydroxy coumarin was dissolved in 11.89 mmol of sodium hydroxide (100 mL water) (Figure 1). 4-hydroxy coumarin solution was kept for attending the temperature of 0–5 °C. Diazonium salt was slowly added to the cold solution of the coupler. Coupling was performed for 4–5 hrs with controlled conditions (0–5 °C, pH 7–8). Finally, the dye preparation reaction was successfully confirmed using the 2-naphthol solution. The dye cake was filtered, washed 5 times with hot deionised water and 5 times with absolute ethanol. The cake was dried in an oven for 3 hrs at 50–55 °C. Dye was further purified by dissolving it in dichloromethane (DCM), filtered, and reprecipitated by adding ethanol to the filtrate. Precipitated dye was filtered and dried in the oven at 50–55 °C for 4 hrs.
Polycyclic aromatic hydrocarbons (PAHs): Updated aspects of their determination, kinetics in the human body, and toxicity
Published in Journal of Toxicology and Environmental Health, Part B, 2023
Fernando Barbosa, Bruno A. Rocha, Marília C. O. Souza, Mariana Z. Bocato, Lara F. Azevedo, Joseph A. Adeyemi, Anthony Santana, Andres D. Campiglia
PAH absorption through inhalation occurs through the mucus lining of the bronchi. Absorption through the oral route occurs via the gastrointestinal tract, where up to 50% of ingested PAHs are absorbed in humans (ATSDR (Agency for Toxic Substances and Disease Registry) 1995; Bauer et al. 2018). The dietary source is the most common exposure route of PAHs for humans; BaP and fluoranthene are the most common PAHs detected in food (ATSDR Agency for Toxic Substances and Disease Registry 1995). PAHs may also be absorbed through dermal exposure by passive diffusion (Beriro et al. 2016). Typically, absorption through inhalation is expected to be higher than through skin. However, it is possible that dermal absorption of PAHs might outweigh absorption through inhalation, especially with LMW PAHs (Lao et al. 2018). LMW PAHs such as 1-naphthol (1-OH-Nap), 2-naphthol (2-OH-Nap), and 1-hydroxyphenanthrene (1-OH-Phe) are rapidly absorbed through the skin among Chinese populations that were exposed to barbecue fumes (Lao et al. 2018).
Association between exposure to air pollutants and attention-deficit hyperactivity disorder (ADHD) in children: a systematic review and meta-analysis
Published in International Journal of Environmental Health Research, 2022
Mengjie Zhang, Changhong Wang, Xinxin Zhang, Huiling Song, Yan Li
Abid Z et al. (Abid et al. 2014) conducted a case–control study with 1,257 pairs of children and adolescents aged between 6 and 15 years, recruited from the National Health and Nutrition Examination Survey (NHANES). Incidences of ADHD were assessed from parental reports of whether a child had ever been doctor-diagnosed with ADHD. PAH concentrations were measured based on urinary metabolite concentrations (nanograms per liter (ng/L)). Five exposure variables were used in this analysis: 1-pyrene, 1-naphthol, 2-naphthol, fluorine ‘FLUO’ metabolites (2-fluorene + 3-fluorene), and phenanthrene ‘PHEN’ metabolites (1-phenanthrene + 2-phenanthrene + 3-phenanthrene). No association was found between these five exposure variables and ADHD (RR: 1.00, 95% CI: 0.60–1.69; RR: 1.00, 95% CI: 0.60–1.69; RR: 0.59, 95% CI: 0.35–1.01; RR: 1.40, 95% CI: 0.72–2.72, and RR: 0.71, 95% CI: 0.36–1.39, respectively).