Long-term stability of several endocrine disruptors in the first morning urine samples and their associations with lifestyle characteristics was written by Jia, Lu-Lu;Luan, Yu-Ling;Shen, Hui-Min;Guo, Ying. And the article was included in Science of the Total Environment in 2022.Related Products of 620-92-8 The following contents are mentioned in the article:
Parabens, triclosan (TCS), bisphenols, benzophenones, and phthalates are typical endocrine disruptors (EDs) with short half-lives in the human body. The concentration levels of those EDs in a spot urine sample are frequently used in exposure assessment studies, and the reproducibility of urinary levels of these nonpersistent EDs should be considered. In the present study, we consecutively collected 45-day first morning void (FMV) urine samples, as well as daily questionnaires, in six recruited participants and measured the urinary concentrations of six parabens, TCS, nine bisphenols, five benzophenones, and ten phthalate metabolites by using high-performance liquid chromatog.-tandem mass spectrometry. MeP, EtP, PrP, TCS, BPA, BPS, BPF, and most phthalate metabolites were frequently detected (over 62% of samples). The intraclass correlation coefficients (ICCs) for ED concentrations in FMV urine samples ranged from fair to excellent for MeP (0.683), EtP (0.702), BPA (0.505), BPS (0.908), BPF (0.887), BP-3 (0.712), mMP (0.661), mEP (0.523), mBP (0.500), miBP (0.724), mBzP (0.961) and all metabolites of DEHP (0.867-0.957), whereas they were low for PrP (0.321) and TCS (0.306). After creatinine adjustment, the values of ICCs for most target EDs were increased with mild to significant improvement. The stability of ED concentrations was affected by daily diet (MeP, TCS, BPA, mMP, miBP, mBP and mBzP), food containers (PrP and mECPP), use of personal care products (HMWP metabolites), pharmaceuticals (EtP) and recorded activities (BPS, mEHP, mBzP, mEHHP and mEOHP), as confirmed by a general linear mixed model. Furthermore, extending the FMV sampling period improved the probability of acceptable reproducibility (ICCs > 0.40) of MeP, EtP, BP-3 and mEP concentrations For BPS, BPF and HMWP metabolite concentrations showed high probabilities (>80%) of acceptable reproducibility in the last three days, and the increasing sample size slowly improved the ability to discriminate the subjects. The results were exactly the opposite for BPA concentrations This study involved multiple reactions and reactants, such as 4,4′-Methylenediphenol (cas: 620-92-8Related Products of 620-92-8).
4,4′-Methylenediphenol (cas: 620-92-8) belongs to alcohols. A strong base can deprotonate an alcohol to yield an alkoxide ion (R―O−). For example, sodamide (NaNH2), a very strong base, abstracts the hydrogen atom of an alcohol. Tertiary alcohols cannot be oxidized at all without breaking carbon-carbon bonds, whereas primary alcohols can be oxidized to aldehydes or further oxidized to carboxylic acids.Related Products of 620-92-8
Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts