What does thin layer chromatography suggest?
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I sure hope you have more information than you're giving us.  Typically profs will narrow the choices to one example of each major class of organic compound.  If you have the whole universe of canidates to choose from, you will need a lot more than these simple test.\n\nTLC:  In one of your textbooks or handouts, you should have a short list of organic candidates vs their Rfs.  Assuming you are using silica gel or alumina plates, ethyl acetate is about twice a strong a chromatographic mobile phase as dichloromethane (DCM) (see linked pdf, p. 15).  The fact that your unknown moved at all in ethyl acetate but hardly at all with DCM lets you know that your compound is fairly polar.  This is not an alkane or a fatty acid/ester.\n\nSolubility:  Not soluble in water?  It's not a saccharide, short-chain acid, alcohol or phenol.  Not soluble in base means it's definitely not a carboxylic acid or a phenol.  Soluble in acetone means it's not a fat or long-chain fatty acid.\n\nSo, what are we left with?  Ethers, ketones, esters and aldehydes.  I suggest you look in the chromatographic tables you have for one of these compounds that has the same Rf values and melting point you've quoted us.\n\nGood luck.
336109
Freezing only works on a certain percentage mixture.  Chromatography on regular phase silica would work the best using a non polar hydrophobic solvent.
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gas chromatographt (GC) and High Performance Liquid Chromatography (HPLC) are different , and to understand why you must think about what chromatography is:\n\nChromatography in its simplest form is like putting ink on blotting paper and watching the colours separate.\nLiquid chromatoraphy uses a "column" which is made from bare or bonded silica, it separates a mixture of compounds by how polar they are. You can use a gradient of different  solvents.\n\nGC also uses a column, but it is a capillary column and instead of using a liquid to carry your mixture which needs to be separated it uses a carrier gas, like nitrogen. You can vary the temperatures in both LC and GC to aid better resolution.\n\nGC is used for more volatile compounds and LC is used more less volatile. HPLC usually refers to reversed phase, normal phase is where the column is vare silica which is very polar. Bonded silica is bonded with hydrocarbons which is non polar.\n\nThe thing to remember is that "like attracts like" so if the column in non polar, the compound to elute first will be the most polar.\n\nTo summarise, they are both separation techniques, one uses gas and the other liquid. You would choose which one to uese depending on how volatile the compounds which you want to separate are.\n\n(^_^)
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Perhaps the thrombin and recombinant protein molecules are sufficiently different to separate using column chromatography.
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Either:\n\n(a) you're not getting a very clean separation, as the peaks should be vivid\n\nor\n\n(b) your detector is insuitable for the acids you're studying.\n\nAtleast, that's my analysis. Any A-Chem experts here?
878037
Suspect this is what you mean...\n\nSuppose you have 0.500 g of a substance you believe is pure...\nyou analyse it and determine that it contains 0.300 g of the substance you are looking for..\nso your sample is (0.300/0.500) x 100% pure  = 60%
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Chromatofocusing (CF) is a variant of ion\nexchange chromatography. It is fast. It supports\nhigh capacity. It gives high resolution. It\nprovides unique selectivity.
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Not sure about which kind electrophoresis you are talking (PAGE, agarosis or other), but loading dye does NOT help to see separated products. \nTwo major functions of the loading dye are: \n1) to stain the sample you are loading so you can see where and how you loaded, \n2) to make the sample more viscous so it sinks into wells and does not float - that is why loading buffers contain glycerol.\nDepending on the type of electrophoresis, loading dye may have other constituents with specific functions, i.e. SDS-PAGE loading dye usually contains beta-mercaptoethanol or DTT, which help to keep proteins in denatured state.
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These should be sufficient: \nhttp://www.tigerdirect.com/applications/Category/category_tlc.asp?CatId=318&
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Validation is a process that consists of at least four distinct steps:\n\n1.   software validation, \n2.   hardware (instrumentation) validation/qualification, \n3.   method validation \n4.   system suitability \n\nThe process begins with validated software and a qualified system. Then a validated method using the qualified system can be developed. Finally it is all wrapped together, in a total validation, using system suitability. Each step is critical to the overall success of the process\n\nMETHOD VALIDATION should include: \nLinearity: the range of linearity is checked by injections of 5-6 concentrations of the reference standards (in triplicates) below and above the expected concentration of the \nsamples (20%-120%). The slope and intercept are determined. r >= 0.999, and the range of linearity (in conc. terms) is established. \n\nAccuracy is measured as the (amount measured)/(amount claimed) in the following procedures: \nIn drug formulations: a standard is added to the placebo (80%, 100%, 120%), and the recovery is measured \nRecovery from sample preparation procedures (such as dilution, extraction or filtration) should be established. \n\nSolution stability of the samples (A fresh sample is compared to one which was left in solution for the entire duration of the test procedure). \n\n Intermediate precision or ruggedness: 5 measurements of the first step of accuracy under two different occasions (two columns, or two operators). \n\nLimit of detection (LOD) and limit of quantification (LOQ): \nThe intercept from the linearity test (in section 5.a) can be used for LOQ measurements (intercept x 5 or 10). \nAnalysis of repeatability at the quantification limit, using both sample and reference standard. Concentrations that yield 10-15% RSD will be acceptable as LOQ concentrations. \n\n Robustness of the chromatographic method: variables in this test can be the following: column batch #, solvent strength in the mobile phase, temperature, flow rate, pH of the mobile phase, ionic strength in the mobile phase, sample diluent, \ninjection volume, wavelength of detection. The parameter measured: response, retention time, selectivity and/or resolution. \n\n=)
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When what is mixed is not fully disolved into the liquid medium.  It usually settles.  A cenrifuge will not separate out the components that are not part of the solution.
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Well.......here goes. This experiment relies on the solvent solution being absorbed into the paper, and climbing upwards. This then allows the separation of the test material / substance, which follows the solvent solution. Most solvents will quickly evaporate when introduced to the air, so for more accurate results, and an overall truer picture, the container should be sealed.
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The two should be separable by HPLC
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Here are some of the more common applications of these techniques:\n\nGas Chromatography - Flame Ionization Detector, also called GC-FID.  This method is used to analyze mixtures of substances which have an appreciable vapor pressure and are capable of burning.  GC-FID is often used to periodically check a reaction mixture to see how far a particular reaction has gone.  It is also used to check for purity of the final product and to check for undesirable impurities.  \n\nHPLC can also be used in a similar way to GC-FID except that it is better at analysis of non-volatile compounds.  HPLC is often used to analyze the final purity of a product, or to analyze the concentration of a pharaceutical product in a physiological sample (blood, plasma, urine, etc).  \n\nUV-vis is good at measuring the concentration of a UV-absorbing compound in a matrix which contains no other UV-absorbers.  Sometimes you can take your final product and dissolve in non-uv absorbing solvent and measure the UV-vis absorbance to determine concentration or assay.\n\nThe above are just some of the more common uses.  There are many more uses for these techniques in the Pharma industry.
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Use English dear.  Putting "Why" in front of an instruction does not a question make.\nI assume you are referring to a chromatogram.\nThe simple answer to the obvious question is that ink is comprised of one or more organic pigments (often phthalocyanine based) and will develop on a chromatogram just the way the applied pigment will.  This will confuse you beyond your wildest expectations.\nInstead, use pencil, which is primarily graphite (a form of carbon) which will not be carried up the chromatogram by the solvent mixture.
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liquid chromatography  separates by charge at a given pH\ngel chromatography  separates by size\n\nthen there is electrophoresis\n\nNow would be a good time to point out I failed one biochemistry exam 4 times\n\ngood luck.
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It is a form of partition chromatography in which a liquid phase flows down a column packed with a solid phase.\nIn column chromatography, the stationary phase, a solid adsorbent, is placed in a vertical glass (usually) column and the mobile phase, a liquid, is added to the top and flows down through the column (by either gravity or external pressure). Column chromatography is generally used as a purification technique: it isolates desired compounds from a mixture.