Rapid Spectrophotometric Method for Assessing Hydroperoxide Formation from Terpenes in Essential Oils upon Oxidative Conditions.
Hannes BitterlingPeter LorenzWalter VetterJürgen ConradDietmar R KammererFlorian C StintzingPublished in: Journal of agricultural and food chemistry (2020)
Essential oils are widely used in the food and cosmetics industry as natural flavoring and fragrance substances. For this reason, a thorough quality control applying selected analytical methods is required. Oxidation along with hydroperoxide formation is an important drawback during production and storage of essential oils. Hydroperoxides constitute the main products formed upon photo-oxidation of essential oils. Due to hydroperoxide instability, gas chromatography (GC) and high-performance liquid chromatography (HPLC) analyses are required. According to the European Pharmacopoeia, titration is the official method for oxidation assessment. However, this analysis is time-consuming, and large sample quantities are required. Here, we present a simple and accurate spectrophotometric method for the detection of peroxide trace amounts in essential oils and terpenes. The principle is based on the formation of Wurster's red, which is enforced by the peroxide-driven oxidation of N,N-dimethyl-p-phenylenediamine dihydrochloride (DMPD). The method was validated using dibenzoyl peroxide (DBP) and cumene hydroperoxide (CHP). To demonstrate the suitability of the method for routine analysis, various oxidized terpenes and essential oils were chosen. Moreover, photo- and thermal oxidation experiments were compared and evaluated using gas chromatography/mass spectrometry (GC/MS) and a synthesized limonene-2-hydroperoxide (Lim-2-OOH) reference standard to gather detailed information on the structural changes of the respective terpenes.
Keyphrases
- gas chromatography
- high performance liquid chromatography
- tandem mass spectrometry
- gas chromatography mass spectrometry
- simultaneous determination
- solid phase extraction
- mass spectrometry
- hydrogen peroxide
- quality control
- electron transfer
- liquid chromatography
- ms ms
- loop mediated isothermal amplification
- nitric oxide
- risk assessment
- visible light
- social media
- drinking water
- clinical practice
- label free