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Weights, Volumes and Concentrations
Published in Barbara A. Hauser, Practical Manual of Wastewater Chemistry, 2018
Each piece of volumetric glassware is for a specific purpose. Beakers are meant only for mixing chemicals; they should not be used for measuring volumes. Beakers have the least calibration accuracy of all laboratory glassware. Erlenmeyer flasks are to be used for titration; the narrowed tops are designed to keep the liquid from splashing out of a swirling flask. These flasks are not accurate enough to measure liquids in. Volumetric flasks, graduated cylinders and pipets are the most accurate, and are meant for measuring liquid volumes in. Use these whenever exact measurements are indicated.
Reactive extraction of protocatechuic acid by di-n-octylamine and optimisation with Box–Behnken design
Published in Indian Chemical Engineer, 2023
İsmayil İsayev, Özge Demir, Aslı Gök, Şah İsmail Kırbaşlar
Three different PCA aqueous solutions were prepared. The concentrations of the solutions were as follows: 0.01, 0.02 and 0.03 mol kg−1. The concentration of PCA has been selected according to its concentration range in the fermentation broth [3–7,36,37]. In total, 10 mL of the acid solution was taken in an Erlenmeyer flask and 10 mL of the organic phase (solvent + DOA) was added to the Erlenmeyer flask. Mixtures were shaken in a rotary shaker for 2 h. From the preliminary tests, the shaking time was to complete the extraction procedure. The sample was centrifuged (Nüve, ST200) at 4000 rpm for 20 min. After phase separation, the raffinate phase was separated by a syringe. The absorbance has been read on a UV–Vis spectrometer at 251 nm. Calibration curves were constructed with tseven points by serially diluting PCA solution (y = 9507.7x + 0.0047). To make sure the values were consistent, they were examined three times. After that, the acid concentration in the extract phase was determined by a mass balance. The experimental layout is shown in Figure 1. The distribution coefficient (KD) of the acid and the extraction efficiency (E%) were determined as follows [27,38]: where[HA]aq signifies the acid concentration in the raffinate phase and [HA]org refers to the acid concentration in the extract phase.
Synthesis and characterization of Salicornia bigelovii and Salicornia brachiata halophytic plants oil extracted by supercritical CO2 modified with ethanol for biodiesel production via enzymatic transesterification reaction using immobilized Candida antarctica lipase catalyst in tert-butyl alcohol (TBA) solvent
Published in Cogent Engineering, 2019
Adewale Johnson Folayan, Paul Apeye Lucky Anawe, Augustine Omoniyi Ayeni
Eight hundred millilitres of filtered Salicornia oil (Bigelovii and Brachiata) were measured separately by using measuring cylinder and transferred into a 2,000 mL PYREX Erlenmeyer flask with glass stopper. The oil was heated to a temperature of 50°C with the aid of water bath. This was followed by the addition of 200 mL of methanol (analytical grade) which was initially preheated and maintained at a temperature of 50°C. About 13.60 g (30 wt.%) of Candida antarctica lipase catalyst immobilized on a macroporous acrylic resin particles (polyhydroxyethylmethacrylate) were added to the Oil–Alcohol mixture inside the Erlenmeyer flask. However, because immobilized enzymes are subjected to inactivation mostly by methanol (Drapcho, Nhuan, & andWalker, 2008), hence 400 mL of an inert-solvent (TBA) was added to the mixture to annul the effect of immobilized enzyme inactivation.
Optimization for alkali extraction of windmill palm fibril
Published in The Journal of The Textile Institute, 2018
Changjie Chen, Guicui Chen, Zhong Wang, You Zhang, Guohe Wang
WPSF (2 g) was placed in 250-mL Erlenmeyer flasks. Distilled water (200 mL) together with different concentrations of NaOH (1, 1.5, and 2 wt%) and hydrogen peroxide (1.6, 3.2, and 4.8 wt%) were used as solvents. The solvent (250 mL) was poured into each flask so that the WPSF was fully immersed in the solvent. Each Erlenmeyer flask was covered with plastic wrap during the experiments to prevent the solvent from evaporating. The flasks comprising the WPSF and the solvent were incubated at different temperatures (70, 80, and 90 °C) in a temperature controlled water bath and extracts were drawn at regular time intervals (210 min). A gauze was used to filter the fiber. Subsequently, the single fibers were washed under running water to remove any traces of alkali on the surface and dried naturally.