Abstract: A simple‚ eco-friendly‚ stability-indicating HPLC method was developed for the determination of Donepezil Hydrochloride (DH) in tablet dosage form in presence of its pharmacopoeial related compound (Donepezil related compound A) and its different degradation products. The chromatographic conditions were optimized to achieve the highest performance parameters using Zorbax Eclipse Plus C18 rapid resolution column (4.6 X 100 mm‚ 3.5 µm)‚ with a mobile phase composed of 72.5 % acetate buffer
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Results and discussion: I. a. How would you compare that relative reactivity of Na and k -Sodium and potassium react somewhat similar when reacting with water however they are slightly different. Sodium moves because of the hydrogen coming off of it and has a low melting point while potassium’s reaction is faster and enough heat is produced to set light to the hydrogen coming off of it. Each leaves a pink color hue in the water. Discuss the similarities and differences in the behavior of the metals
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Pigments were first extracted from tomato paste by a 50/50 mixture of acetone/hexanes; these miscible molecules act together as one organic solvent. Pigments choose the organic layer over the tomato paste with water‚ which allowed for their extraction. K2CO3 is an ionic base that was added to deprotonate the citric acid. The ionic product of the reaction in figure 3 now prefers the aqueous layer‚ which serves to wash the pigments of the acidic impurity. Saturated NaCl pulls any water into the
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Keeping it Liquid Introduction: Phase changes within our world play a key role in how substances can be manipulated‚ and formed. A phase change is‚ “a change from one state (solid or liquid or gas) to another without a change in chemical composition” (Collins Italian Dictionary‚ 2016). Moreover‚ in this experiment‚ the use of tert-butanol was needed to perform phase changes. Tert-butanol is colorless oily with sharp odors‚ mixes with water‚ and has a freezing point of 78 degrees Farenheit (PubChem
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Materials and Methods: PLGA (50:50 copolymer compositions; MW 30‚000 Da)‚ berberine chloride hydrate (MW 371.81 Da)‚ poly vinyl alcohol (MW 89‚000 Da) and 15 and 50 mL Corning centrifuge tubes were purchased from Aldrich (St. Louis‚ MO‚ USA). Acetone was purchased from Fischer Scientific Laboratory (Fair Lawn‚ NJ‚ USA). Phosphate buffer pH 7.0 was purchased from EMD Chemicals Inc. (Gibbstown‚ NJ‚ USA). 0.2 micron syringe filters were obtained from Millipore Corporation (Carrigtwohill‚ Ireland). 1
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3.3 Results and Discussion 3.3.1 Particle Size of Asphaltenes. DLS was utilized to obtain the hydrodynamic radius of asphaltenes in toluene‚ which could help understand the behaviors of asphaltenes in the bulk solutions and oil/water interfaces. Figure 1 shows the particle size distribution of asphaltenes under different concentrations at 23 ℃ and under 2000 mg/L at different temperatures. A summary of the average particle size under different concentration and temperature conditions is shown in
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Diffusion is the molecular net movement from a higher concentration to a lower concentration. For instance‚ when a person is smoking‚ the smoke diffuses into the air. The molecules in the smoke‚ released from the cigarette‚ travel through the air. Here is how it occurs. When molecules are close enough‚ they collide with each other‚ their kinetic energy changes. Due to the direct relationship between diffusion and molecular kinetic energy‚ the molecules move away from the point of the collision as
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The purpose of column chromatography is to separate one compound from another by the differing polarities in the compound. This technique is important in organic chemistry because certain experiments may require the separation of compounds in solution to be used for chemical synthesis and/or analysis of a particular desired product by isolating it. Fluorene is to be separated from 9-fluorenone using the technique of column chromatography. The success of separation and purity is determined with analyzation
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98.) Consider the unbalanced redox reaction: Cr2O72- (aq ) + Cu(s ) → Cr3+ (aq ) + Cu2+ Balance the equation in acidic solution and determine how much of a 0.850 M K2Cr2O7 solution is required to completely dissolve 5.25 g of Cu. Nitric acid is usually purchased in concentrated form with a 70.3% HNO3 concentration by mass and a density of 1.41 g/mL. How much of the concentrated stock solution in milliliters should you use to make 2.5 L of 0.500 M HNO3? Mass %= Mass Solute/ Mass Solvent + Mass
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Chromatographic conditions Shimadzu VP-ODS column is (250 mm x 4.6 mm i.d.‚ 5 µm particle size)‚ Shimadzu‚ Kyoto‚ Japan. The mobile phase consisted of a mixture of 0.3% TEA‚ 10% n-propanol in a solution of 0.1 M SDS adjusted to pH 2.8 using 0.02 M orthophosphoric acid. It was pumped at a flow rate of 1 mL min-1. The column was kept at ambient temperature and the wavelength of the detector was at 225 nm. Standard solutions Stock solutions of LVD‚ CBD and ETC containing to 1.0 mg mL-1 were prepared
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