Two small additional peaks at δ = 0.8 and δ = 1.6 were found may be due to impurities present. 1H-NMR spectrum of PHA isolated from glucose or molasses media indicated characteristic signals of PHB, namely a doublet at 1.26 ppm, which is attributed to the methyl (CH3) group coupled to one proton while a doublet of quadruplet at 2.51 ppm due to the methylene (CH2) group adjacent to an asymmetric carbon atom bearing a single proton. The third signal at 5.25 ppm, which was attributed to the methine (CH) group. 1H-NMR is a very sensitive method for determining the domain size and miscibility, which is difficult to identify by conventional microscopic or thermal analysis (Kichise et al., 2002).The values of the chemical shifts as well as the assignments of the 1H-NMR signals, which appeared in the spectra are in agreement with results obtained by Kichise et al. (2002) and typically identical to peaks of the authentic PHB sample produced from Aldrich Company, which clearly shown that the extracted biopolymer from the B.thuringienesis in this study was poly-3-hydroxybutyric acid.
What is the concentration of a solution that contains 10.0 moles of HCl in 5.50 L of water? a. 1.82 M c. 0.550 M b. 15.5 M d. 4.50 M 12. A beaker contains 0.7 L of a 2 M calcium carbonate solution.
We concluded that the rate of hydrolysis of (CH3)3CCl is directly proportional to water content in the solvent mixture. Aims of experiment • Determine the rate constants for hydrolysis of (CH3)3CCl in solvent mixtures of different composition (50/50 V/V isopropanol/water and 40/60 V/V isopropanol/water) • Examine the effect of solvent mixture composition on the rate of hydrolysis of (CH3)3CCl Introduction With t-butyl chloride, (CH3)3CCl, being a tertiary halogenoalkane, it is predicted that (CH3)3CCl reacts with water in a nucleophilic substitution reaction (SN1 mechanism), where Step 1 is the rate-determining step. The reaction proceeds in a manner as shown
The calculated value was 1.6 x 10^-5. Conclusions The resulting Ka of the acetic acid from this experiment’s calculations was consistent with the experimental results. The experimental percent of CH3COOH was calculated at 1.6 x 10^-5, while the actual value was 1.8 x 10^-5. The calculated value is much lower because the pH read from the graph at half of the equivalence was higher than the actual value. To have gotten a 0% error between the experimental and actual value for CH3COOH, the pH would have been measured at about 4.75, which is slightly more acidic than 4.80.
The ultimate analysis result shown to the chemical components of corncob, high content of aliphatic hydrocarbon compounds was indicated by high of the H/C molar ratio and low amount of polar compounds was presented by low value of the O/C molar ratio. The HHV of corncob was rather low (17.71 MJ kg-1) when compared with a fossil fuel as coal (24.00 MJ kg-1).14 Table 1 Characterization of biomass samples. 3.2 The effect of pyrolytic temperature. The result of yield and composition of bio-char from corncob in the
3.1 Phenolics in buckwheat honey Figure 1 illustrates the wide variety of HPLC profiles of six buckwheat honey samples. As can be seen, these samples could be divided into two main types. The first type exhibited very similar chromatograms, including samples 1, 2, 3 and 4. The retention time of most compounds is 20 to 70 min. Conversely, the second type include sample 5 and 6.
2.3. Synthesis of 2-(2-(Morpholinomethyl)-1H-benzimidazol-1-yl)acetohydrazide (4) To a solution of compound 3 (0.01 M, 2.89 g) in methanol (60 mL), 99% hydrazine hydrate (1 mL) was added and the mixture was refluxed for 6 h. The reaction mixture was cooled and the solid thus obtained was filtered, washed with cold water and recrystallized with ethanol to obtain the compound 4. 2.4. General procedure for synthesis of 1-{(5-substituted-1,3,4-oxadiazol-2-yl)methyl}-2-(morpholinomethyl)-1H-benzimidazoles (5a-r) An equimolar mixture of compound 4 (0.001 M) and substituted carboxylic acid in phosphoryl chloride (POCl3) was refluxed for 8–12 h. Then reaction mixture was cooled, poured into ice-cold water and neutralized with 20% w/v NaHCO3 solution.
INSTRUMENTATION AND ANALYSIS CONDITIONS The HPLC analysis was performed on waters alliance using PDA detector. The separation was carried out using Hypersil BDS C-18 (150×4.6mm, 3µ) conditions. The mobile phase composition of mixture of buffer and acetonitrile (80:20)was selected for the separation. Analysis was carried out at a flow rate of 1.0ml/min with a detection wavelength 280nm and the injection volume was set at 10µL. Isocratic pump mode was used and an ambient temperature was
During the experiment we diluted with sterile water 1:10 and 1:100 depending on the different drug concentration. Determination of minimal inhibitory concentration (MIC) The MIC of Ciprofloxacin for both strains were estimated by using the broth microdilution method recommended by the Clinical and Laboratory Standards Institutes (CLSI) guidelines
The limit of quantification (LOQ) and limit of detection (LOD) were determined based on the slope and the standard deviation of the response using the signal-to-noise ratio (S/N) as per ICH Guidelines Q2(R1) 2005. The LODs for Lamivudine, Abacavir and Dolutegravir were found to be 0.021, 0.330 and 0.038µg/mL respectively, and the LOQs for Lamivudine, Abacavir and Dolutegravir were 0.056, 1.320 and 0.095 µg/mL respectively. (table 6 ) Robustness Robustness of the method was performed by making slight deliberate changes in the analytical methodology like flow rate and solvent ratio. It was observed that this method did not significantly affect in system suitability parameters like USP tailing factor, theoretical plates and resolution, which confirmed that the developed HPLC method is