Capillary gas chromatography-mass spectrometry of volatile and semi-volatile compounds of Salvia officinalis

The essential oil and infusion of Salvia officinalis leaves have been widely applied in traditional medicine since ancient times and nowadays subjected to extensive research of their antibacterial, antiviral and cytotoxic properties. This paper shows chemical composition data of S. officinalis leaves essential oil isolated by steam distillation using a Clevenger-type apparatus. Also, the paper presents the chemical content of volatile and semi-volatile compounds of S. officinalis leaves infusion. The volatile and semi-volatile compounds of S. officinalis leaves infusion were isolated by solid-phase extraction (SPE) and liquid-liquid extraction with hexane and dichloromethane. SPE was carried out on 500 mg octadecylsilane (C18) cartridges and elution with dichloromethane. Liquid-liquid extraction was performed with hexane and dichloromethane. The essential oil in dichloromethane and infusion extracts in hexane and dichloromethane were analyzed by gas chromatography coupled with mass spectrometry. The quantitative results obtained by solid-phase extraction and liquid-liquid extraction showed that SPE on C18 performed the highest recovery of the volatile compounds from infusion sample.     

Green Extraction of Carotenoids from Fruit and Vegetable Byproducts: A Review

Carotenoids are characterized by a wide range of health-promoting properties. For example, they support the immune system and wound healing process and protect against UV radiation’s harmful effects. Therefore, they are used in the food industry and cosmetics, animal feed, and pharmaceuticals. The main sources of carotenoids are the edible and non-edible parts of fruit and vegetables. Therefore, the extraction of bioactive substances from the by-products of vegetable and fruit processing can greatly reduce food waste. This article describes the latest methods for the extraction of carotenoids from fruit and vegetable byproducts, such as solvent-free extraction—which avoids the costs and risks associated with the use of petrochemical solvents, reduces the impact on the external environment, and additionally increases the purity of the extract—or green extraction using ultrasound and microwaves, which enables a significant improvement in process efficiency and reduction in extraction time. Another method is supercritical extraction with CO₂, an ideal supercritical fluid that is non-toxic, inexpensive, readily available, and easily removable from the product, with a high penetration capacity.     

Specific features of the magnetic aftereffect in high-purity diamagnetic beryllium

The behavior of the effective shear modulus and low-frequency internal friction in magnesium-thermal beryllium condensate before and after the treatment of samples in a weak constant magnetic field has been studied. The data obtained have been used for calculating the temperature and time dependences of the ratio between the dislocation motion velocities during and after the magnetic action. It has been shown that the exposure of samples to a magnetic field and their aging after the magnetic action radically change the character of the temperature dependences of the dislocation motion velocities. Empirical expressions describing these dependences have been obtained. It has been demonstrated that the magnetic aftereffect in diamagnetic beryllium has a complex character, which indicates the presence of several magnetic memory mechanisms.     

Ionic-strength gradient during chromatofocusing in carboxylic columns

The presence of a strong electrolyte in mobile phases essentially influences the pH gradient profile generated by chromatofocusing. The variation in the strong electrolyte concentration in the chromatofocusing system is studied. The ionic strength gradient ends far more early than the pH gradient; anomalous segments of the pH gradient profile match the general trend of the ionic strength in the system. The pH gradients obtained under identical conditions on carboxylic sorbents MacroPrep 50 CM and MN are compared. The influence of the KNO3 concentration in the mobile phases on the gradient profiles is studied. Optimum systems are chosen for generating the smoothestlinear pH gradients.     

Permutable pairs of quasi-uniformities

We continue investigating the lattice (q(X),⊆) of quasi-uniformities on a set X. In particular in this article we start investigating permutable pairs of quasi-uniformities. Among other things, we show that the Pervin quasi-uniformity of a topological space X permutes with its conjugate if and only if X is normal and extremally disconnected.