Abstract In this study, microfunnel-supported liquid-phase microextraction method (MF-LPME) was optimized and applied for the determination of some chlorophenoxyacetic acids (CPAAs) from natural water samples. The extraction was performed with 540 μL toluene which was retained at the surface of the sample solution using an upside down microfunnel. After the extraction, toluene was moved in...

Ultrasound-assisted extraction is evaluated as a simpler and more effective alternative to conventional extraction methods for the extraction of bioactive compounds from natural product. This study investigated the use of ultrasound-assisted extraction to extract three dibenzylbutyrolactone lignans, including tracheloside, hemislienoside, and arctiin from Hemistepta lyrata. Factors such as extr...

Asphaltene precipitation is traditionally modeled using polymer solution theories or cubic equations of state. We propose another approach based on artificial neural network technique to model onset of precipitation of dissolved asphaltene in the solution of solvent + precipitant. A mathematical model based on feed-forward artificial neural network technique, which takes advantage of a modified...

This preliminary study presents a new method for the determination of dissolved gases in sea-water. After headspace extraction, gaseous compounds are separated by GC on a dual column adsorption system. The individual species are thereafter eluted to three different detectors (thermal conductivity, flame ionization and FPD) using a second switching valve. The analysis is quantitative for methane...

The present article includes the Ultrasound-Assisted Extraction (UAE) of Citrus unsiu Marc. leaves rich in polyphenols. The best possible combinations of solvent, pH of the media, solvent/solid ratio, extraction time, extraction temperature and particle size were obtained for the maximum extraction of Total Phenolic Compounds (TPC) and Total Flavonoid Compounds (TFC) by us...

1.1 This test method covers three procedures for extraction and measurement of gases dissolved in electrical insulating oil having a viscosity of 20 cSt (100 SUS) or less at 40°C (104°F), and the identification and determination of the individual component gases extracted. Other methods have been used to perform this analysis. 1.2 The individual component gases that may be identified and determ...

This preliminary study developed a novel cellulose pretreatment method for cost-effective cellulosic utilization using a modified cuprammonium solution as a solvent to dissolve cellulose followed by molecular oxygen/Fenton depolymerization. The modified cuprammonium solution is composed of cuprammonium solution and a special catalyst that could efficiently enhance cellulosic oxygen sensitivity ...