Phenols are ubiquitous in our surroundings. For example, phenol compounds occur in food components and additives such as liquid smoke, wine and whiskey. Liquid smokes are usually obtained from the condensation of wood smoke produced by smoldering wood chips or saw dust under limited oxygen, and thermal degradation of wood produces variety of compounds including phenol derivatives. Similarly, in whiskey, phenols come either form peat firing, or in the process of ageing in oak barrels, or both. Phenolic derivatives contribute to smoke flavor, taste, and color of these products and have antibacterial and antioxidant properties. In this work, we quantify phenols by first converting them to indophenols by reaction with Gibbs reagent, followed by ESI mass spectrometric analysis. Unlike the conventional methods, which use solvent extraction followed by GC-MS analysis, or by using colorimetric analysis, which is non-specific in terms of the phenolic derivative, the use of Gibbs reaction allows for the simultaneous detection of phenol derivatives in mass spectroscopy without a separation step. Quantification of phenols in food and additives is carried out by including an internal standard. Examples of applications that will be discussed include a comparison of phenolic composition of different flavored liquid smoke food additives (hickory vs mesquite vs pinewood vs applewood) and an assessment of the smokiness of scotch whiskeys by examination of the guaiacol and syringol content. Finally, by using this method, it is possible to quantify phenols as low as 0.1 mg/L in commercial products very accurately within five minutes.

Mass spectroscopic analysis of phenol derivatives by Gibbs reaction

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.