A simple, rapid and efficient method has been developed for the extraction, preconcentration and determination of cobalt (II) and nickel (II) ions in water samples by air-assisted liquid-liquid microextraction (AALLME) coupled with graphite furnace atomic absorption spectrometry (GFAAS). In the proposed method, much less volume of an organic solvent was used as the extraction solvent in the abs...

Ciênc. Tecnol. Aliment., Campinas, 21(1): 10-13, jan.-abr. 2001 1 Recebido para publicação em 11/09/98. Aceito para publicação em 30/06/00. 2 Jahan Vegetable Oil Co., Research Department. 16 Daman Afshar st., wali-Assr Ave., Above wanak sq. Tehran 19697, Iran. SUMMARY Spent nickel catalyst (SNC) has the potential of insulting the quality of the environment in a number of ways. Its disposal has ...

The present study is aimed to examine and compare the storage stability of seed kils extracted form red pepper (Capsicum annuum L.) waste by green techniques (cold pressing, ethanol solvent, ultrasound-assisted solvent extraction). In accordance with this purpose, oil samples were stored for a period 6 weeks at 60°C under accelerated conditions analyzed weekly intervals peroxide, conjugated die...

Oilseeds are crucial for the nutritional security of the global population. The conventional technology used for oil extraction from oilseeds is by solvent extraction. In solvent extraction, n-hexane is used as a solvent for its attributes such as simple recovery, non-polar nature, low latent heat of vaporization (330 kJ/kg) and high selectivity to solvents. However, usage of hexane as a solven...

Marine algae are a rich source of bioactive compounds. This paper outlines the main bioactive compounds in marine algae and recent advances in novel technologies for extracting them. Novel extraction technologies reviewed include enzyme-assisted extraction, microwave-assisted extraction, ultrasound-assisted extraction, supercritical fluid extraction, and pressurized liquid extraction. These tec...

The genus Haplophyllum, which belongs to the Rutaceae family, includes 18 species in Iran. In this study, after collecting plant material, botanical identification and suitable drying, the essential oils from aerial parts of Haplophyllum robustum Bge. were extracted by three different isolation techniques, conventional hydrodistillation (HD), microwave-assisted hydrodistillati...

A combined Monte Carlo and quantum mechanical study was carried out to analyze the tautomeric equilibrium of 2-mercaptopyrimidine in the gas phase and in aqueous solution. Second- and fourth-order Møller-Plesset perturbation theory calculations indicate that in the gas phase thiol (Pym-SH) is more stable than the thione (Pym-NH) by ca. 8 kcal/mol. In aqueous solution, thermodynamic perturbation...

In a supercritical fluid extraction (SFE) unit, one generally can change the temperature, pressure, extraction bed size, solvent flow rate, among others, in order to maximize the global yield. The morphology of the solid substrate particle can also influence the extraction efficiency, since the solvent must cross diffusive paths inside the solid particle, in order to extract specific compounds ...

Recently there is a great interest in using high energy techniques (HET) which involve microwave or ultrasound-assisted extraction (MAE and UAE) for isolation of natural bioactive compounds from plant foods. Such bioactive compounds are phenolics which were determined from sunflower (Helianthus annuus L.) kernels and hulls (defatted) utilising two different high energy extraction techniques, ul...