In most cases these precursors have been prepared from
carbonyl compounds via reductive alkylation of protected hydrazines [3-5] (Scheme 1, A).
These include tobacco-specific nitrosamines (TSNAs),
carbonyl compounds, metals, volatile organic compounds (VOCs), and phenolic compounds.
In a previous study, the occurrence of
carbonyl compounds (formaldehyde, acetaldehyde, acrolein, furfural and EC) was reported in all stages of vinification, including grapes and the respective wines (FERREIRA et al., 2018).
A mixture of1-aminoanthracene-9,10-dione (1 mmol), variety of aromatic
carbonyl compounds (1 mmol) and dodeca-tungstosilicic acid/[P.sub.2][O.sub.5] (0.2 g, 1 mol% of 1-aminoanthraquinone/[P.sub.2][O.sub.5]) as a catalyst was ground in mortar with a pestle under solvent free conditions at room temperature for 1-3 min (Scheme 1).
A classical synthesis of these compounds involves the condensation of [alpha],[beta]-unsaturated
carbonyl compounds with hydrazines [11].
Some of these compounds, which include
carbonyl compounds, cyclohexanone, phenol and isophorone, might be critical when present in higher concentrations in children's toys.
Moreover, they might be the result of secondary reactions of amino acids (cysteine, histidine, and lysine) with reactive
carbonyl compounds (ketones, aldehydes), emerged in lipid peroxidation or glycation/glycoxidation reactions.
Low molecular
carbonyl compounds, existing in the cigarette smoke and automobile exhaust, aroused extensive attention due to their adverse effects on human health [1,2].
The chemical, which is also known as Brady's reagent, is a chemical used to identify whether unknown compounds contain
carbonyl compounds.
Dr Dave Kinnson, a chemistry safety adviser from the University of Southampton, explained: "It's used to test
carbonyl compounds and in the school labs it is often used as part of the A-level programmes.
More than 100 volatile flavour compounds have been detected in yoghurt and these include
carbonyl compounds, alcohols, acids, esters, hydrocarbons, aromatic compounds, sulfur-containing compounds, and heterocyclic compounds [11 - 14].