Densitometric Investigations of Chemical Durability of Pyrocatechol

Abstract

The chemical durability of pyrocatechol was investigated on silica gel, as well as in solutions, in relation to different storage conditions. Investigations were made using a NP‐TLC method on silica gel and with chloroform–methanol (9:1, v/v) as mobile phase. Densitometric measurements were made with λ=200 nm using a Camag densitometer. Chromatographic plates were treated by temperature of 120°C, as well as UV radiation (λ=254 nm) during 120 minutes before spotting, and after spotting of pyrocatechol solutions. It was stated that, after 120 minutes at 120°C of exposure of pyrochatechol spotted on silica gel, a decrease of as much as 83% pyrocatechol was observed. However, 15% of pyrocatechol spotting on silica gel decreased after 120 minutes of UV radiation (λ=254 nm). The influence of water, solution of physiological salt, and ethanol on the durability of pyrocatechol was also investigated. Pyrocatechol solutions mentioned above were subjected to exposition of visible light, UV radiation (λ=254 nm), and temperature (40°C). It was stated that, ethanol has the biggest stabilizing properties in relation to pyrocatechol. Pyrocatechol dissolved in a solution of physiological salt, as well as heated in a temperature of 40°C and irradiated with UV light, undergoes slightly bigger changes in relation to the water solution of pyrocatechol.

Keywords:

• NP‐TLC
• Densitometry
• Pyrocatechol
• Chemical durability

Acknowledgment

This research was financed by the Ministry of Science and Information Society Technologies by resources reserved for science in the years 2005–2008 as research project No. 3 T09A 155 29.