Application of Essential Oils as green corrosion inhibitors for metals and alloys in different aggressive mediums

The use of inhibitors for the protection metals and alloys against corrosion in different aggressive environment is one of the best choices. In recent years, essential oils have been explored as green corrosion inhibitors because to their bio-degrability, eco-friendliness, low cost and easy availability. The inhibition performance of these natural products may be to the adsorption, by a synergistic effect, of their different phytochemical constituents including oxygenated monoterpens and sesquiterpens as well as hydrcarbons products. The inhibition effectiveness of these green corrosion inhibitors was evaluated by using numerous techniques like weight loss method, polarization study and AC impedance spectra. The protective layer (film) formed on the metal surface has been analyzed by IR spectroscopy, scanning electron microscopy coupled with EDX and X-ray photoelectron spectroscopy (XPS) techniques. This review presents most of the research work published in recent years on the use of essential oils as green corrosion inhibitors for various metals and alloys in different mediums

Gas Chromatography-Mass Spectrometry Analysis and Comparison of Volatile Components Obtained by Hydrodistillation and Headspace Solid Phase Microextraction (HS-SPME) from Teucrium luteum subsp. flavovirens

The main purpose of this work is to investigate the comparative chemical analysis of essential oil (EO) isolated by hydrodistillation (HD) and volatile fraction (VF) detected by headspace solid-phase micro-extraction (HS–SPME) obtained from Teucrium luteum subsp. flavovirens using Gas Chromatography–Retention Indices (GC-RI) and GC–Mass Spectrometry (GC-MS). 63 volatile compounds identified in hydrodistilled essential oil (HD), representing 89.9% of the total oil, while HS-SPME revealed 50 components constituting 99.3% of the volatile material. The chemical composition of EO comprised mainly of of oxygenated sesquiterpenes (48.6%) while, hydrocarbon monoterpenes were detected in higher concentrations in VF (54.1%). The comparative analysis of two chemoprofiles obtained by two methods shows quantitative and semi-qualitative differences. The current study is the first report involving rapid analysis of volatile components of T. luteum subsp. flavovirens by HS-SPME

Antifungal activity of essential oil from Santolina pectinata lag., against postharvest phytopathogenic fungi in apples

The purpose of this study was to investigate the chemical composition and antifungal activities of essential oil (EO) of Santolina pectinata aerial parts. The analysis of EO using gas chromatography (GC-FID) and gas chromatography-mass spectroscopy (GC-MS) allowed the identification of 34 components, which (Z)-heptadeca-10,16-dien-7-one was the major constituent with 28 % of the total oil. The antifungal activities of this oil in liquid and vapor-phase against three phytopathogenic fungi causing the deterioration for apples, including Botrytis cinerea, Penicillium expansum and Rhizopus stolonifer were evaluated in vitro by using the poisoned food (PF) and the volatile activity (VA) methods. The obtained results showed a significant inhibition of the studied EO inhibited significatively against the mycelial growth of all fungal strains tested (p<0.05). B. cinerea and P. expansum showed a strong sensitivity to the studied oil at all concentrations and VA assay was consistently found to be more effective than PF technique. The minimum inhibitory concentrations (MICs) of this oil were 0. 25 and 1 µL/mL against these strains when using VA and PF assays, respectively. The overall results suggest that S. pectinata EO could be used as an antifungal preservative to control post-harvest diseases of apples. The antifungal activities of S. pectinata EO from Morocco are reported for the first time