for epimers and isobars Iltaf Shah1‚ Ricky James1‚ James Barker2‚ Andrea Petroczi1 and Declan P Naughton1* Abstract Background: Recently‚ the accuracies of many commercially available immunoassays for Vitamin D have been questioned. Liquid chromatography tandem mass spectrometry (LC- MS/MS) has been shown to facilitate accurate separation and quantification of the major circulating metabolite 25-hydroxyvitamin-D3 (25OHD3) and 25hydroxyvitamin-D2 (25OHD2) collectively termed as 25OHD. However
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homogenate was made by adding the buffer to the liver of the quail after one hour centrifuge at 12300 RPM materializing at 4°C. Precipitation protein was working by ammonium sulfate; it loaded directly to column 2’‚ 5’ ADP Sepharose 4B affinity chromatography‚ which has been a high affinity to NADP+ substrate. The flow rate of elution was 23 ml/hr. Taking 18 fractions‚ checking activity for each fraction at 340 nm. The activity found in fraction tube six to fourteen. This process was materializing
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The starting material for this lab was the dialyzed sample (stored at -20ᵒ C) from the previous lab. The CM sephadex resin (taken in a 50 mL tube) was already made swollen using Buffer C (20 mM HEPES‚ pH 7.9; 1 mM EDTA; 50 mM KCl). The dialyzed sample was thawed to the room temperature and gently poured over the resin. The tube was capped and kept on a rocker at room temperature for 1 hour. The tube was then centrifuged in a HS-4 rotor at 2500 rpm (1200g) for 5 minutes at 4ᵒ C. Supernatant was discarded
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this experiment‚ a mixture of two compounds‚ cyclohexane and toluene‚ was separated into fractions by the techniques of simple and fractional distillation. The individual fractions that were gathered from the distillation were analyzed using gas chromatography (GC) and used to compare the efficiencies of the two different distillation techniques. The ultimate goal of this experiment was to determine whether simple or fractional distillation was the more efficient means of separating volatile compounds
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method was used to divide hexane and toluene from a mixture (50:50) of hexane and toluene. Hexane was separated from toluene and was observed from the gas chromatography‚ it showed that hexane increased from 0.0.873 to 0.886 moles. Once the mixture of toluene and hexane hit 70 degrees in the experiment‚ the distillate was used for the gas chromatography. Hexane was higher in the distillate stage. The first drop of condensation appeared at 79°C. The volume of the distillate was 0.88ml and 0.98ml for the
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The product was then purified by flash chromatography and analyzed by IR‚ 1H NMR and 13C NMR. The synthesis of piperonylontitrile was successful. There was a yield of a pale yellow crystal of 36%. The average recovery is 51% with there being a range from 0-94 %1. A reason for a smaller yield than
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Using this reaction and its product‚ a redox experiment was performed to familiarize students with important organic chemistry laboratory techniques including proper mixing in an oxidation reaction‚ extraction‚ infrared spectroscopy‚ and gas chromatography. Reactants cyclohexanol and sodium hypochlorite (NaOCl) undergo a redox reaction and when combined with the catalyst acetic acid (HOAc) and solvent water (H2O)‚ form the product cyclohexanone along with sodium chloride (NaCl) and water. In the
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MIXTURES‚ SOLUTIONS‚ SUSPENSIONS AND COLLOIDS MIXTURES A mixture is a combination made up of two or more different substances which are mixed but are not chemically bonded. There are also types of mixtures such as homogeneous mixtures and heterogeneous mixtures. SOLUTIONS A solution is defined as a homogeneous mixture composed of a solute; a substance dissolved into another substance known as a solvent. They can also be defined as groups of molecules that are mixed up completely in even
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binds the nucleoside inhibitor site. When it binds this site‚ it stabilizes the inactive T state and blocks the catalytic site which needs to be open for enzyme activity to occur. The glycogen phosphorylase b was purified with hydrophobic column chromatography and the concentration was determined with a Bradford Assay. The kinetics of glycogen phosphorylase b were studied by finding a molar extinction coefficient‚ 0.1617 mM cm-1 A-1‚ for
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and various amount of H2O2 and H2O. Solutions were left to react for 3 days‚ and analyzed by size exclusion chromatography and UV-Vis absorbances were taken. In the large scale experiments‚ approximately 100 mg of each compound was mixed with fixed amounts of Fe2+ and H20 and varying h2O2 amounts. They sat until the compound reacted away and were analyzed via size exclusion chromatography. They were then purified by dialysis in water for 3 days‚ changing water several times throughout. Following
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