HPLC analysis defination?
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HPLC is High Performance/Pressure Liquid Chromatography.\nThe liquid sample is loaded onto the chromatography column, which is packed with a stationary phase.\nA mobile phase (solvent which is flushed through the column) is then flushed through the column.\nThe different components are then eluted separately, depending on their characteristics and the type of stationary phase and mobile phase being used.\n\nThe HPLC machine can be interfaced with something like an NMR machine to give a detailed breakdown of each fraction.
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Depends on the method that you are using, and/or the age of the column. If the column is older than one year, or has more than 1000 hours of run time, it may be suspect. \n\nWith regards to the sample you are running, make sure that what you are running is compatible with an ODS column. Some chemistries will react with the silane groups and become permanently attached to the column. Also, make sure there are no matrix issues that could be obscuring your results. The sample might have to be washed or cleaned to remove/reduce matrix effects.\n\nWith the method you are running, make sure that you are properly cleaning the column after each run because some things may be retained on the column and not eluting.  You may have to run a stronger cleaning solvent to clean the column and then re-equilibrate with your running solvent.  Also, make sure that your running solvent stays constant and is not changing due to evaporation or any other factors. \n\nObviously to give reproducible results the methods that you use must remain as constant as possible. Check each of your method parameters to make sure nothing is changing. \n\nHope this helps without going into a treatise on HPLC theory and methodology.
560605
With IR you can dilute your soln so you have a bit more of it and then stick it on a plate and check out the peaks. That can give you a good idea of what you have... or there is HNMR, and CNMR, but it really depends on how much you have of the substance. If you have a general idea of what it might be then check the PH and give it a good guess... or use an indicator that might form some kind of ppt. with the substance in the soln . I've found that a refractive index really isnt the way to go because it isnt as reliable as other tests. Gas chromotograpy and Thin layer chormotograpy both require a general idea of what you might be coming up with... GC can be sketchy and you dont want to loose any sample on a test that might not tell you much, same with TLC, you would haev to be careful with the slovent interaction with the "unknown" that you have.
860724
The link below gives a method and chromatogram.  Bear in mind that you will need to prevent the degradation of ascorbic acid during the analysis.  This may be done by adding EDTA and HCl to the solutions, but you will have to work out the concentrations.
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The column is one of the most important components of the HPLC chromatograph because the separation of the sample components is achieved when those components pass through the column. Normally, columns are filled with silica gel because its particle shape, surface properties, and pore structure \nhelp to get a good separation. Silica is wetted by nearly every potential mobile phase, is inert to most compounds and has a high surface activity which can be modified easily with water and other agents. Silica can be used to separate a wide variety of chemical compounds,and its chromatographic behavior\nis generally predictable and reproducible.\n\nUsually, analytical columns are protected by a guard column which is an essence a disposable (or sacrificial) top of the main analytical column. The guard column is the final filter both mechanical and chemical. In addition to removing debris, it also can adsorb undesirable sample components that \notherwise might irreversibly bind and possibly change the stationary phase of the analytical and preparative columns. Although economy alone is not a persuasive argument for the use of guard columns, the need for a long stable \nlife of the analytical column to obtain reliable and reproducible results is perhaps even more important.\n\nThere are several column types, according to their function, they \ncan be classified as:\n\n a) Normal phase \n\nIn this column type, the retention is governed by the interaction of the polar parts of the stationary phase and solute. For retention to occur in normal phase, the packing must be more polar than the mobile phase with respect to the sample. Therefore, the stationary phase is usually silica and \ntypical mobile phases are hexane, methylene chloride, chloroform, diethyl ether, and mixtures of these. \n\n b) Reverse phase \n\nIn this column the packing material is relatively nonpolar and the solvent is polar with respect to the sample. Retention is the result of the interaction of the nonpolar components of the solutes and the nonpolar \nstationary phase. Typical stationary phases are nonpolar hydrocarbons, waxy liquids, or bonded hydrocarbons (such as C18, C8, etc.) and the solvents are polar aqueous-organic mixtures such as methanol-water or acetonitrile-water.\n\n c) Size exclusion \n\nIn this column type, molecules are separated according to size. Small molecules penetrate into the pores within the packing while larger molecules only partially penetrate the pores. The large molecules elute before the \nsmaller molecules.\n\n d) Ion exchange \n\nIn this column type the sample components are separated based upon attractive ionic forces between molecules carrying charged groups of opposite charge to those charges on the stationary phase. Separations are made between \na polar mobile liquid, usually water containing salts or small amounts of  alcohols, and a stationary phase containing either acidic or basic fixed sites.
667496
First take 30ml of 1% starch solution and add 6 ml of concentrated HCL acid and distribute them into six test tubes labeled as 'A' TO 'F'. Place them in boiling water bath and take them out at various time intervals like 0', 1', 5', 10', 13' and 15' minutes respectively.\n\nDivide the tubes content into three tubes and do iodine, Fehlings and Benedicts tests in the fractions.\n\nyou can do osazone test in the 15' minute fraction for the conformation of the presence of glucose.\n\nCompare the color developed in different tubes.  It clearly shows difference
819482
why dont you check out the XII th comprehensive chemistry practical reader??.........or anyother practical readers available in the market...............suggested ones are like soap formation........food adulteration.........fruit and vegetable juice analysis, toothpaste analysis.........caffeine.........aspirin......tanic acid found in tea leaves..........sea water .........all u have to do is buy that comprehensive  chemistry practical reader and choose from the given list............................\nbest of luck!!! :)
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Typically labs have densitometers for gel electrophoresis analysis.  There has also been increasing use of capillary electrophoresis systems for IFE/s and SPE.
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In thin layer chromatography or TLC the stationary phase consists of a thin layer of adsorbent like silica gel, alumina, or cellulose on a flat carrier like a glass plate, a thick aluminum foil, or a plastic sheet.\n\nThe process is similar to paper chromatography with the advantage of faster runs, better separations, and the choice between different adsorbents. TLC is a standard laboratory method in organic chemistry. Because of its simplicity and speed TLC is often used for monitoring chemical reactions and for the qualitative analysis of reaction products.\n\nTLC plates are made by mixing the adsorbent with a small amount of inert binder like calcium sulfate (gypsum) and water, spreading the thick slurry on the carrier, drying the plate, and activation of the adsorbent by heating in an oven. The thickness of the adsorbent layer is typically around 0.1–0.25 mm for analytical purposes and around 1–2 mm for preparative TLC.\n\nSeveral methods exists to make colorless spots visible:\n\nOften a small amount of a fluorescent dye is added to the adsorbent that allows the visualization of UV absorbing spots under a blacklight ("UV254"). \nIodine vapors are a general unspecific color reagent. \nSpecific color reagents exist into which the TLC plate is dipped or which are sprayed onto the plate. \nOnce visible, the Rf values of the spots can be determined. These values should be the same regardless of the extent of travel of the solvent, and in theory are independent of a single experimental run. They do depend on the solvent used, and the type of TLC plate.\n\nThin layer chromatography is also used in finding which pigments a plant contains. By taking extract of the plants cellulose and applying the technique, one can adequately find the pigments. It may also be used to detect pesticides or insecticides in food, or in forensics to analyze the dye composition of fibers.
702007
do the experiment and note what processes are taken (ex growing a plant-1st put seed in dirt 2nd water etc etc) this is analysis\n\ndid you take some steps during your experiment that may have caused some delays or errors (ex did you remember to give your plant lighting?)
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Chromatography is a method of separating chemical mixtures into their components.\n\nOriginally the process was developed for use on colored mixtures whose progress during separation could be followed by observing bands or spots of different colors during the process.\n\nThe major features of chromatography are an absorbent medium and a solvent (called an eluent).  The simplest version of chromatography can be demonstrated on a white napkin by making a spot with an ink pen near an edge of the napkin, then putting the napkin's edge (but not the spot) into a saucer of water.  The napkin will wick up the water and it will spread to the spot and past it.  As it goes past the spot, different colors will come out at different rates, revealing the differing dyes used to make the pen ink.  A ballpoint pen may work also.\n\nChromatography may be carried out using paper, silica gel, diatomaceous earth and many other absorbent materials, and they may be made into sheets on a backing, or used to fill columns ("column chromatography") or tubing.  There are literally hundreds of available packing materials.  The solvent or eluent is chosen to be not too good, meaning it will not simply dissolve all of the test material and sweep it through the medium, but will allow the competition between mobile phase (where the chemicals can move) and stationary phase (where the chemicals are held by the medium), as the competition is crucial for separation to occur.\n\nThere are additional types of chromatography, such as liquid chromatography and gas chromatography, that have been developed since the earlier color-based processes, but they share the need for a mobile phase and a stationary phase to enable the separations, and a detection system.\n\nHope this helps.  As you can imagine, I've just scratched the surface of this interesting and useful process.
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Links at\n\nhttp://www.itt.edu/staff/boyter/links/index.html#CHEMISTRY_CHROMATOGRAPHY
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Chromatography is a family of analytical chemistry techniques for the separation of mixtures. It involves passing the sample, a mixture which contains the analyte, in the "mobile phase", often in a stream of solvent, through the "stationary phase." The stationary phase retards the passage of the components of the sample. When components pass through the system at different rates they become separated in time, like runners in a mass-start foot race. Each component has a characteristic time of passage through the system, called a "retention time." Chromatographic separation is achieved when the retention time of the analyte differs from that of other components in the sample.\n\nA chromatograph takes a chemical mixture carried by liquid or gas and separates it into its component parts as a result of differential distributions of the solutes as they flow around or over a stationary liquid or solid phase. Various techniques for the separation of complex mixtures rely on the differential affinities of substances for a gas or liquid mobile medium and for a stationary absorbing medium through which they pass; such as paper, gelatin, alumina or silica.\n\nAnalytical chromatography is used to determine the identity and concentration of molecules in a mixture. Preparative chromatography is used to purify larger quantities of a molecular species. Most of the following refers to analytical chromatography. This is a method used to divide/separate mixtures.
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ChemDraw from CambridgeSoft Corporation may be help you. Look at www.cambridgesoft.com
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Volumetric analysis is limited by precision of calibration and may be affected by concerns such as temperature and mixing.\n\n"Spectrometry" may cover a wide variety of technologies, but if we consider absorption spectroscopy techniques limitations include Beer's law deviations, noise, calibration error, and interfering components in the case of impure samples.\n\nColorimetry can be thought of as absorption spectroscopy taken at a single wavelength.  The limitations are similar, but the affects of interfering components will be harder to detect.
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If you buffer the mobile phase to the isoelectric pH of the amino acid you are interested in, its mobility will be retarded compared to others. You could calibrate your ninhydrin using known amino acid sample and reflectance colorimeter reading of a standard area of stationary layer. That nice simple technique is the advantage of TLC together with sensitivity and non destructive properties.\nAn alternative is HPLC ,using liquid mobile phase under high pressure and columns of  solid stationary phase.
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Well, when I was an organic chemist, I mostly mixed and poured.  So, what you do is, take something that's kinda like what you're making, add something that's very reactive (so toxic and/or explosive), mix, and heat.  Wash out the impurities, then either crystallize or distill-crystallization-kinda fun, distilling-monumentally boring(although those explode sometimes too).  Then analyze by NMR, TLC, HPLC,GC and IR.  Some people just do the analysis.\nThat's about it.  It was kinda fun, but it got old, and it was dangerous.  And scale varies depending on where you work.