A total of 0.1 ml of supernatant was added to cuvette containing 1.9 ml of 50mM phosphate buffer (pH 7). The reaction was started by the addition of 1 ml freshly prepared 30mM H2O2. The rate of decomposition of H2O2 was measured spectrophotometrically at 240 nm. Catalase values were expressed as n moles H2O2 consumed/min/mg protein. Measurement of lipid peroxidation TBARS, a measure of lipid per oxidation, was measured as described by Ohkawa .
The sample was transferred to a 250 ml conical flask kept in water bath for alkali treatment. 75 ml of 17.5% caustic soda was measured using a measuring cylinder at 20°C. 15 ml of 17.5% NaOH was added and fibres were macerated gently with a flattened glass rod for 1 minute. 10 ml more NaOH was added and the solution was mixed for 45 seconds. 10 ml NaOH was again added and mixed for 15 seconds to make lump free slurry.
This solution was diluted with diluents to gae a concentration of 0.1 mg/ml solution each of Amoxicillin trihydrate. The HPLC method was applied to the solutions and the results obtained were shown in table 4.6.11. System suitability solution: 25.0 µg/mL each of of USP Amoxicillin RS in Diluent. Precision
Upon finding the actual concentrations of salicylic acid, concentration of aspirin in the flask at various times can be found using the equation [aspirin]t = [aspirin]0 – [salicylic acid], since at constant volume, number of moles of initial aspirin decrease to form salicylic acid. Initial concentration of aspirin formed as follows: [aspirin]0 = 0.212g / (180.157gmol-1 * 50/1000 L) = 0.0235 mol L-1. Thus using the first test as sample, [aspirin]t = 0.0235 – 9.981*10-4 = 0.0225 mol L-1. To find the rate constant, we will need to log the value of [aspirin]t and plot it against time to find the rate constant. Figure 1 shows the diluted and actual concentrations of salicylic acid, the concentration and log value of aspirin at various times.
Linoleic acid peroxidation was initiated by the addition of 4 mM FeSO4.7H2O, incubated for 60 min at 37oC and terminated by the addition of 2 mL of ice cold trichloroacetic acid (10% v/v). An amount of 1 mL of thiobarbituric acid (1% w/v in 50 mM NaOH) was added to 1 mL of the reaction mixture, followed by heating at 95oC for 60 min. The reaction sample was read at 532 nm.7 The percentage of linoleic acid peroxidation inhibition activity was calculated using the following equation: % Inhibition = [(AB - AA)/AB] x 100, where AB, absorption of blank sample, AA, absorption of test sample. 2.5.4. Metal chelating activity Briefly, 2 mM FeCl2 was added to different concentrations of test sample and reaction was initiated by the addition of 5 mM ferrozine.
Thus, about 0.002 moles, or 0.4 g, of KHPh is needed. At the endpoint, the number of moles of NaOH equals the number of moles of KHPh used: MNaOH = moles KHPh Eq. 2 VNaOH in liters or MNaOH = g, KHPh x 1000 mL/L Eq. 3 204.23 g/mole mL, NaOH Once the NaOH solution has been standardized, it can be used to determine the acid neutralizing capacity of an antacid tablet. Determination of the Acid Neutralizing Capacity of an Antacid Tablet The stomach has an acidic interior generated by dilute HCl, “stomach acid”, which insures proper digestion.
The final volume was recorded. A pH probe connected through Microlab was calibrated using buffer solutions of pH 4.00, 7.00, and 10.00. The calibrated pH probe was used in order to measure the pH of the titrated solution of the unknown weak acid. These same steps were repeated except 2 mL of the strong base were titrated into the weak acid solution instead of 4 mL. This process was repeated 10 times.
Briefly, a solution containing 0.3 gr (3 mmol) succinic anhydride and 0.4 ml (3 mmol) of triethylamine in 10 ml of THF was dropwise added to a stirred solution of 1 mmol of sPEG in 10 ml of anhydrous THF for 12 h at 75 C. The solvent of product solution was evaporated by a rotary evaporator and the obtained dark yellow viscous liquid was dissolved in acidic water (pH= 3). In the following,
Smaller and smaller organelles may be sendimented by successive centrifugation at increasing speed. 1ml of the homogenate (H) was pipetted into a clean microfuge tube labelled P1. The tube labelled ‘P1’ was centrifuged at 1,000g for 10 minutes to sediment the first pellet (P1). The supernatant was carefully removed with an automatic pipette and placed in a micro centrifuge tube labelled ‘P2’. The P2 tube was then placed in the refrigerated centrifuge at a speed of 15,000g for 30-60 minutes at 4°C.
Hepcidin solution (20 μL) was added to the plasma before extraction with the beads, whilst in parallel another sample of plasma underwent extraction and then the same amount of hepcidin was added. The percentage of recovery was calculated as (AreaPRE / AreaPOST) x 100, where AreaPRE represents the samples with hepcidin added before bead treatment and AreaPOST the samples with hepcidin added after bead treatment. The values obtained were above 90 % in all cases. 4.4. Dietary intervention The functional juice aronia-citrus juice (ACJ) included in this study was a mixture of citrus juice (95%) and 5% aronia extract (Aronia melanocarpa), based on a drink model developed before and reported by Gonzalez-Molina et al .