what about preparative thin layer chromatography?
448305
That's where you scrape the TLC coating where your analyte of interest makes a spot.  Then you can dissolve the analyte using a suitable solvent and centrifuge to let the TLC solid stationary phase settle to the bottom.\n\nThis process allows you to separate an analyte of interest from other compounds it is mixed with.
551829
EDTA has very little selectivity so I doubt you will find much more.Masking/demasking agents such as cyanide complexes,phosphate anions.. are nothing else than complexation examples.Another method is called kinetic masking; for example determination of Cr and Fe in steel sample solution (under cool condition,the EDTA will react with Fe first and after you heat the solution the EDTA will react with Cr).The choice of indicator might increase selectivity (different indicators have different reaction rate)but I'm not sure about that one...
888975
There is no such thing as "mass chromatography"\n\nThere is 2 other options that you can be refering to  LC/GC/MS systems that separate the elution and atomize the solvent as it comes off the column, and send it to the quadrapole in the MS for detection of mass.\n\nThere is also GPC (Gel Permeation) Chromatography which is perhaps more what you might be looking for.   This type of system is similar to HPLC, but is lower pressure (100 bar) and instead of separation by Polarity, this particular column will separate by molecular mass; with the larger molecules having the shortest elution time, and the smaller molecules having the longer elution time.  This works best if used with a Refractive index detector.
951472
Longer the column better resolution you can get during separation. And wider one might do same. It's the surface contact with compound and silica used for chromatography. And adding pressure to it help increase total area of surface contact.
150817
What Is It??\nHello, everyone, and welcome to the wonderful world of chromatography! What is chromatography, you ask?? Well, quite simply, it is a broad range of physical methods used to separate and or to analyze complex mixtures. The components to be separated are distributed between two phases: a stationary phase bed and a mobile phase which percolates through the stationary bed. \n  \n  \nHow Does It Work? Like Magic!\nA mixture of various components enters a chromatography process, and the different components are flushed through the system at different rates. These differential rates of migration as the mixture moves over adsorptive materials provide separation. Repeated sorption/desorption acts that take place during the movement of the sample over the stationary bed determine the rates. The smaller the affinity a molecule has for the stationary phase, the shorter the time spent in a column.
116691
Chromatographyis a way to seperate out different parts of a mixture.  The idea is that you pass a fluid (either a gas or a liquid) down a long path, and the different molecules will move at different rates.  THat's the long and short of it.  So the molecules that move fastest get to the end first, and the slowest come out last.  You seperate things by making them race, and similar chemicals will take a similar amount of time to finish the race.\n\nI'm assuming that you're getting confused by things like "solid phase" and "mobile phase" and "bind affinity" and such.  The idea though is that you set up different types of obstacles depending on which things you want to win the race.  Sometimes this is dine by using something with a lot of positive charges, so that things with negative charges will get stuck and the things that are neutral or positively charged will win the race. Sometimes you sort things by size, by using a gel as an obstable with a bunch of little pores in it: little guys get lost inside and the fat guy wins the race.  With gases, you can just make the race really, really, really long, and the lightest parts will move the quickest while the hevy boys lag behind (this is a way that uranium is enriched for nuclear reactors and bombs).
855472
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(^_^)
327573
Let's see...it's desireable because it's likely to be a lot different than your starting material and your derivatizing agent - this gives you confidence that you actually made a derivative and are not just measuring the m.p. of either your unreacted agent or your starting material.  We used this a lot when I took a class called the Analysis of Organic Unkowns.  No instruments were allowed.
823770
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.
480845
The two should be separable by HPLC
489353
I perfectly agree with the previous answerer but I would like to add that the secret stands in the amount of AHA that each preparation contains. If the amount is lower than 7.5% they are generally safe. If it is more than this has to be implemented by the specialist in order to avoid allergies.\n\nKaterina
409824
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.
895495
Take a sample and run a chromatography.
460267
A mono Q column is loaded with very small beads that seperate molecules, usually proteins, by anion exchange- im not sure what level of detail you want.
37898
I worked with HPLC starting in th days when it was called High Pressure instead of High Performance LC.  I used several chromatographs over a five or ten year period.  It is basically a column chromatograph which is scaled down and uses a pump to move the mobile phase.\nThere are some nice sites which can give you the basics.  In addition there is an on-line forum for asking questions.
350756
Retention times for chromatographic techniques are usually a function of column length and composition, so listing the retention times from longest to shortest is probably just convention. However, the analyte with the longest retention time should (in theory) be separated best from any other analytes in your solution, but should also be most distorted when it reaches the detector. Perhaps scaling these graphs in such a way is an attempt to illustrate this point.
591329
Chromatofocusing (CF) is a variant of ion\nexchange chromatography. It is fast. It supports\nhigh capacity. It gives high resolution. It\nprovides unique selectivity.