In this experiment, absorbance at A400 was directly proportional to the number of moles of p-nitrophenol. This shows that there is a linear relationship between the absorbance and the number of moles of p-nitrophenol, which later also shows that there is a linear relationship between the absorbance and the concentration of the p-nitrophenol, as the number of moles of p-nitrophenol will increased when the concentration of p-nitrophenol increased. The R2 value obtained for the standard curve is 0.9997, which indicates that the data obtained fit the line of best fit, showing that the data are accurate. The values of absorbance per µmol of p-nitrophenol were then obtained from the gradient of the curve, which will later be used in calculation in determining the enzyme activity. Based on Graph 3, it was shown that the enzyme activity of alkaline phosphatase increased with the increase of MgCl2
When analyzing the R2 values of Graphs 1 and 2, their respective R2 values of 0.9956 and 0.99062 indicate the regression of each trend line fits the data points extremely well. From these consistent graphs, the k values of 1-propanol and 2-propanol were identified to be 0.5753 per minutes and 0.4662 per minutes, correspondingly. The half-lives of each were then calculated: t1/2 of 1-propanol = 1.2048 minutes; t1/2 of 2-propanol = 1.4868 minutes. These oxidation techniques are not only often used in the organic chemistry lab, but are frequently used in various scientific fields and are even used to create home care products. Ultimately, this particular lab resulted in the collection of very plausible
Study indicates that ethanol at an optimal concentration of 25% (v/v) is more effective than water for the extraction of polyphenols which reached the maximum of 69.75 mg of GAE/ g of dry black gram powder The use of lower concentrations of alcohol has the added advantage that the proteins are not likely to be denatured and possibly their physico-chemical and functional properties are not impaired and indicated that the protein content of the extract is not decreased by the extraction at low concentrations of alcohol. There will be drop in total phenolic content with 100% ethanol9. Effect of extraction temperature on extraction of phenolic compounds The extraction of phenolic compounds was checked in the temperatures ranging from 300C to 600C. At 30°C, there was increase in polyphenol extraction. At higher temperature, the extraction of polyphenols was not effective; this may be due the decomposition of phenolic compounds or may be due to the breakdown of phenolic content which are present in the sample network.
It has been observed that phenol has many adverse effects on aquatic ecosystem even when they are exposed to small concentrations. Reduction in growth, fecundity and maturity index of aquatic animals was observed (by Saha et al.) as a result of exposure to phenol (1.26 mg L−1) for 90 days. Also, mortality of about 0–30% of fathead minnows (freshwater fish) was observed by Becker and Crass when they were exposed for 96 hrs to a concentration ranging from 5.8–8.0 mg L−1 of phenol. Also, phenol involves in a reaction with chlorine while the treatment of municipal water giving chlorophenols as the product, which are carcinogenic in nature .
Squalene undergoes a two-step cyclization to yield lanosterol catalyzed by sequalene mono-oxygenase and sequalene 2, 3 epoxidase enzymes. Sequalene mono oxygenase is the second committed step in cholesterol biosynthesis and lead to the formation squalene 2, 3 epoxide. This enzymatic reaction require supernatant protein factor (SPF) and NADPH as a cofactor to introduce molecular oxygen as an epoxide at the 2, 3 position of squalene. The activity of supernatant protein factor itself is regulated by phosphorylation/dephosphorylation (Singh et al., 2003). Through a series of 19 additiona lreactions, lanosterol is converted to cholesterol.
Also, part of the chalcopyrite particles is covered with other minerals, which is more abundant at the earliest stages of the skimming process. Based on the kinetic parameters of the flotation process, the optimal granulation distribution range to achieve the maximum flotation rate is 50 to 55 microns in size. According to the above, it is suggested that, before designing of the ore processing system and the concentration of minerals in a deposit, studies on the mineralogy of the ore should be carefully done and the suitable operating conditions will be designed in accordance with the
A considerable narrow size distribution of nano particles was obtained at 0.001 molL-1 concentration (Fig.5), while ploydispersed nano particles were produced at higher concentration. The lower concentration process indicates diffusion limited growth process of nano particles which results in mono dispersed nano particles at lower precursor concentration. Greater rate of reaction at higher concentration of FeCl3 produced large number of metal ions. Therefore the growth process at higher precursor concentration was surface controlled in which the diffusion of growth species from the bulk to the growth surface was sufficiently rapid due to greater availability of metal ions. The mono nuclear growth mechanism of larger nano particles obtained at higher concentration was also responsible for broadening of size distribution of nano particles at 0.005 molL-1 concentration.
Detection : 275nm Flow rate : 2ml/min Injection volume : 20µl Column Temperature: 25oC Run Time : 25min Mobile phase preparation It is prepared by mixing 800ml of Tetrahydrfuran and 1200ml of water mixed and filtered. Preparation of Diluent It is prepared by diluting 68ml of water with Isopropyl Alcohol to 1000ml Preparation of Standard stock solution Weighed 20.95mg of propofol standard and transferred to 25ml of volumetric flask. Add 10ml of diluent, sonicate to dissolve and make up the volume with diluent. Preparation of Sample preparation Transfer 2ml of sample solution into 25ml of volumetric flask. Add 10ml of diluent, sonicate to dissolve and make up the volume with diluent Procedure: Inject blank(inj)(diluent) and standard preparation(5inj) Check for the following system suitability parameters The relative std deviation for replication inj is not more than 1.5% If the system suitability parameters pass, then inject Assay preparation(2inj) and report the chromatograms CALCULATIONS: Calculate the quantity in % of propofol in each ml of inj taken by the formulation.
Batch mode adsorption studies: a. Effect of pH: pH variation is one of the most important parameters controlling the uptake of toxic metals from wastewater and aqueous solutions. The studies were conducted at room temperature with an initial metal ion concentration of 10ppm, 15ppm, 20ppm and constant adsorbent dose of 10gm/l solution, at an agitation period of 30min. Effect of pH on adsorption was conducted at ranges of 2, 4, 6, 8, and 10 in each solution. The maximum percentage of adsorption was found in range of pH between up 2 to 4, and there after it decreases with further decrease in pH between up 6 to 8.
• pH. The degree of ionization of a species is affected by the pH .This, in turn, affects adsorption. The extent of adsorption also depends on temperature, pressure, and concentration in the bulk phase, elemental nature of the adsorbent. Adsorption isotherm A relation between the amount of adsorbate adsorbed on a given surface at constant temperature and the equilibrium concentration of the substrate in contact with the adsorbent is known as Adsorption Isotherm. Phenol Molecular formula C6H6O Structural formula Appearance Physical state: liquid (> 40.9 °C) - solid (< 40.9 °C) Colour: colourless (liquid) - white (solid) Odour Stinging Odour threshold 0.022 - 22 mg/m³ Water solubility At 20 °C: 84 g/L; At 25 °C: 87 g/L; At 68 °C: completely miscible pH value At 20 °C, 10 g/L: 4 - 5 Melting point/freezing point 40.9 °C Density At 20 °C: 1.07 g/cm³; at 25 °C: 1.13 g/cm³ Molecular weight 94.11124