Validated Stability-Indicating GC-MS Method for Characterization of Forced Degradation Products of Trans-Caffeic Acid and Trans-Ferulic Acid

Abstract

When dealing with simple phenols such as caffeic acid (CA) and ferulic acid (FA), found in a variety of plants, it is very important to have control over the most important factors that accelerate their degradation reactions. This is the first report in which the stabilities of these two compounds have been systematically tested by exposure to various different factors. Forced degradation studies were performed on pure standards (trans-CA and trans-FA), dissolved in different solvents and exposed to different oxidative, photolytic and thermal stress conditions. Additionally, a rapid, sensitive, and selective stability-indicating gas chromatographic-mass spectrometric method was developed and validated for determination of trans-CA and trans-FA in the presence of their degradation products. Cis-CA and cis-FA were confirmed as the only degradation products in all the experiments performed. All the compounds were perfectly separated by gas chromatography (GC) and identified using mass spectrometry (MS), a method that additionally elucidated their structures. In general, more protic solvents, higher temperatures, UV radiation and longer storage times led to more significant degradation (isomerization) of both trans-isomers. The most progressive isomerization of both compounds (up to 43%) was observed when the polar solutions were exposed to daylight at room temperature for 1 month. The method was validated for linearity, precision as repeatability, limit of detection (LOD) and limit of quantitation (LOQ). The method was confirmed as linear over tested concentration ranges from 1−100 mg L−1 (r2s were above 0.999). The LOD and LOQ for trans-FA were 0.15 mg L−1 and 0.50 mg L−1, respectively. The LOD and LOQ for trans-CA were 0.23 mg L−1 and 0.77 mg L−1, respectively.

Electron ionization mass spectrometric fragmentation and multiple reaction monitoring quantification of ferulic and p‐coumaric acid trimethylsilyl derivatives in deposited atmospheric particles

“…Ionization of the ester group of the p ‐coumaric acid TMS derivative can take place on the double‐bonded oxygen or on the oxygen linked to the TMS group, giving ions a +● and b +● , respectively (Figure 2). Ion a +● can easily lose TMSO ● to give the ion c + at m/z 219.0835 strongly stabilized by conjugation 16 . However, low‐energy CID‐MS/MS analyses (Table 1) showed that this ion could also be produced from ion d + at m/z 293.1027 resulting from the loss of a methyl radical by the molecular ion b +● .…”

“…to give the ion c + at m/z 219.0835 strongly stabilized by conjugation. 16 However, low-energy CID-MS/MS analyses (Table 1)…”

Energetic Bio-Activation of Some Organic Molecules and Their Antioxidant Activity in the Pulp of the Moroccan Argan Tree «Argania spinosa L.»

“…The identification of vanillin at 80, 90 and 100 °C may be due to the thermal degradation of ferulic acid. The small quantification of ferulic acid in all samples and its low concentration at 90 and 100 °C compared to other temperatures may be due to its conversion to vanillin or its demethylation to caffeic acid [ 28 , 29 , 30 ]. It should be highlighted that our samples are very rich in flavonoids; however, the majority of phenolic acids, such as caffeic acid, salicylic acid, vanillic acid and p-coumaric acid, were not identified in such samples.…”

Investigation of the long-term stability of various tinctures belonging to the lamiaceae family by HPLC and spectrophotometry method

“…In general, the phenolic acids are present as trans-isomers, and after exposure to various extreme conditions (more protic solvent, higher temperatures, longer storage times, etc. ), degrade (isomerized) rapidly (Razboršek et al 2021). The rapid decomposition of trans-rosmarinic acid to its cis-isomer in a protic organic solvent was observed by Razboršek (2011).…”