크로마토그래피 원리의 큰 틀도 마찬가지로 두 상에 대한 분배 차이를 이용하여 분석물을 분리, 정제할 수 있습니다. 다만 크로마토그래피에서 두 개의 상은 하나는 고정하고 다른 하나는 일정 방향으로 이동시켜 사용합니다.
최상의 결과를 위해서는 올바른 시약을 사용함으로써 피크 대칭성을 개선할 수 있습니다.
예를 들어 설탕과 같이 물에 녹기 쉬운 물질을 첨가했을 때 설탕은 기름층에 거의 녹지 않으므로 물층에 많이 존재하게 됩니다. 반대로 식용유와 같이 헥산에 녹기 쉬운 용질을 첨가했을 때는 물층보다 기름층에 많이 존재합니다. 이와같이, 설탕과 식용유는 물과 헥산의 두 상 사이의 존재의 비율(=분배 비율)이 크게 다르기 때문에, 만약 당신과 이 분액깔대기에서 설탕만을 분리하고 싶다면, 분액깔대기에서 물층만을 꺼내 물을 증류시키면 설탕만을 얻을 수 있습니다.
Recording and analyzing data is vital for interpreting the final results of an HPLC experiment. By finding out the chromatogram, analysts can detect and quantify the parts in a mix and assess the accomplishment of your separation.
Degassing is attained in quite a few approaches, but the most typical are using a vacuum pump or sparging by having an inert fuel, including He, which has a low solubility from the cellular phase. Particulate components, which can clog the HPLC tubing or column, are eradicated by filtering the solvents.
we realized how to regulate the cellular period’s polarity by blending collectively two solvents. A polarity index, nevertheless, is simply a guide, and binary cell phase mixtures with equivalent polarity indices might not resolve Similarly a pair of solutes. Table twelve.5.two
In the gas chromatograph the stress from the compressed gas cylinder is enough to press the mobile stage from the column. Pushing a liquid cellular period via a column, even so, takes a great deal a lot more effort and hard work, creating pressures in excessive of several hundred atmospheres.
, which lets us to take a look at a wide choice of cell phases with only seven experiments. We start by adjusting the quantity of acetonitrile during the cell period to generate the best possible separation inside of the specified Investigation time.
Altering the cellular section’s polarity index alterations a solute’s retention variable. As we discovered in Chapter 12.three, nonetheless, a change in k is just not an effective way to improve resolution when the Preliminary worth of k is bigger than 10.
Acid–base chemistry isn't the only illustration of a secondary equilibrium response. Other examples include things like ion-pairing, more info complexation, as well as the conversation of solutes with micelles. We'll consider the very last of these in Chapter 12.seven when we talk about micellar electrokinetic capillary chromatography.
The cellular section flows throughout the stationary period and carries the parts on the combination with it. Different factors vacation at various premiums. Thus the elements divided and found in numerous region in chromatography to separate, determine and quantify.
Numerous different types of detectors are already use to observe HPLC separations, a lot of which make use of the spectroscopic tactics from Chapter 10 or the electrochemical procedures from Chapter 11.
HPLC is often a improved type of column chromatography. The main difference is, here rather than dripping solvent under gravity a force of as much check here as 400 ambiance is used within the chromatography to have a swift separation.
Flow rate problems: Movement price right affects peak condition. A movement fee that is definitely too high can lead to broader peaks due to fewer interaction concerning analytes as well as stationary period.