31 research outputs found
Gas Chromatographic Investigation of Solvents with Partial Miscibility
The solubility parameter theory has been used for the correlation
of infinite dilution activity coefficients of hydrocarbons
in mixed solvents (diethylene glycol and diethylphthalate) having
partial miscibility in the liquid phase. The calculated values were
in good agreement with those determined experimentally by GLC
Desorption of artemisinin extracts of CIM-Arogya by supercritical carbon dioxide
Artemisinin is a drug for chloroquine resistant malaria and cerebral malaria treatments. In the recent past, there was an acute shortage of this drug and hence World Health Organization made a strategy to fulfil the Artemisinin demand.
In this study, artemisinin was extracted by supercritical Carbon Dioxide (SFCO2) from CIM-Arogya, a variety of Artemisia annua, in temperature and pressure ranges of 313.1-333.1 K and 15\u201325 MPa. Artemisinin global yield isotherms were determined obtaining a maximum yield of 3.65 wt%. Artemisinin extracts were also obtained by hexane Soxhlet extraction: then, the crude extracts were purified using SFCO2, after adsorption on silica gel. Different desorption runs were performed with a 6 ml/min CO2 flow rate, in temperature and pressure ranges of 313.1\u2013333.1 K and 15\u201325 MPa. At different time intervals, extracts were collected and analysed: their yields varied from 2.75% to 4.34% function of the experimental conditions. Desorption trials were also correlated with different models
Optimization of SC-CO2 Extraction OF Alpinia Galangal (L.) Wild and Estimation of Cost of Manufacturing (COM) Via SIMULATION Process
n/
The Supercritical carbon dioxide extraction of \u3c9-3, \u3c9-6 lipids and \u3b2-sitosterol from Italian walnuts: A central composite design approach
A central composite design approach was used to optimize the supercritical carbon dioxide (SCCO2) extraction of Italian Walnut oil, considering the effect of pressure (from 82.3 to 317.6 bar), temperature (from 309.7 to 326.5 K) and process time (from 1.5 to 6.5 h) on extraction yield, fatty acid composition and sitosterol content. A multiple regression analysis indicated pressure and time as major parameters influencing the extraction yield. Those parameters also induced changes in the extract compositions giving the opportunity to obtain enriched fractions of polyunsaturated fatty acid (PUFA). Increased PUFA yields were obtained with higher pressure values but, for longer process times, extracts stated augmented amounts of saturated fatty acids. The different solubility behavior of PUFA and other lipids in SCCO2 could be exploited for the production of walnut oil fractions with high PUFA contents that can be considered as starting materials for the development of food supplements or functional foods
New Automated and High-Throughput Quantitative Analysis of Urinary Ketones by Multifiber Exchange-Solid Phase Microextraction Coupled to Fast Gas Chromatography/Negative Chemical-Electron Ionization/Mass Spectrometry
The present research is focused on automation, miniaturization, and system interaction with high throughput for multiple and specific Direct Immersion-Solid Phase Microextraction/Fast Gas Chromatography analysis of the urinary ketones. The specific Mass Spectrometry instrumentation, capable of supporting such the automated changeover from Negative Chemical to Electron Ionization mode, as well as the automation of the preparation procedure by new device called MultiFiber Exchange, through change of the fibers, allowed a friendly use of mass spectrometry apparatus with a number of advantages including reduced analyst time and greater reproducibility (2.01–5.32%). The detection limits for the seven ketones were less than 0.004 mg/L. For an innovative powerful meaning in high-throughput routine, the generality of the structurally informative Mass Spectrometry fragmentation patterns together with the chromatographic separation and software automation are also investigated
The perturbed hard chain theory for the prediction of supercritical fluid extraction: binary mixtures
A comparison between semi-empirical and molecular-based equations of state for describing the thermodynamic of supercritical micronization processes
A Thermodynamic Analysis of Three-Phase Equilibria in Binary and Ternary Systems for Applications in Rapid Expansion of a Supercritical Solution (RESS), Particles from Gas-Saturated Solutions (PGSS), and Supercritical Antisolvent (SAS)
Correlation of activity coefficients at infinite dilution with the wilson and uniquac equations
The problems involved in the determination of the parameters of thermodynamic models of liquid solutions were investigated. The Wilson equation and the UNIQUAC equation both at a single and at two parameters per binary system were focused. The adjustable constants of these models were evaluated on the basis of activity coefficients at infinite dilution determined by GLC