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What is difference between isocratic and gradient hplc?
in isocretic system we use only single mobile phase but in gredent system we use two or more mobile phases.
Why water is not used in normal phase hplc analysis?
In normal-phase chromatography, the stationary phase is polar and the mobile phase is a mixture of non-polar solvents such as hexane and slightly more polar solvents such as isopropanol. water is the most polar solvent of all solvents. If you use water as a mobile phase, the polar analytes will remain dissolved in water and there will be no retention of analytes on the stationary phase. If there is no retention on stationary phase, there is no separation
What is the H.P.L.C. chromatography?
HPLC stands for high performance liquid chromatography. It is a liquid chromatography which involves the separation of the compounds on the basis of their polarity. It is used to analyze, identify, purify & quantify the compounds.
How do you change from reversed phase chromatography to normal phase chromatography?
How do you change from reversed phase chromatography to normal phase chromatography? answer:Water -------> Ethanol ---------> Acetone -----> Ethyl acetate ------>Chloroform ------->HeptaneHow to Change from normal phase to reversed phase chromatography?Heptane ------->Chloroform -------> Ethyl acetate ---->Acetone --------->ethanol -------> WaterMohammad Abdel Qader (Mousa)Lab. SupervisorChemical , Biological and Drug Analysis CenterAn-Najah National University.Nablus Palestinezawatehm@gmail.com 1)To ues reverse phase chromatography solvents like:-Acetonitrile,Methanol in HPLC Grade 2) To use normal phase chromatography sovents like:-Iso propyl alcohol,n-Haxane HPLC Grade
What would you use in a paper chromatography?
We use several things such as stationary phase which is a paper, mobile phase according to your solute and the mixture to be analysed. All these are placed in a closed chamber.
What is difference between isocratic and gradient hplc?
in isocretic system we use only single mobile phase but in gredent system we use two or more mobile phases.
Can you use a C18 column for HPLC with fluorescence detector and methanol as the mobile phase?
Yes, you can use a C18 column and methanol as a mobile phase with fluorescence detector. Fluorescence detector is generally used as it can detect the presence of compounds at a very low concentration.
Why water is not used in normal phase hplc analysis?
In normal-phase chromatography, the stationary phase is polar and the mobile phase is a mixture of non-polar solvents such as hexane and slightly more polar solvents such as isopropanol. water is the most polar solvent of all solvents. If you use water as a mobile phase, the polar analytes will remain dissolved in water and there will be no retention of analytes on the stationary phase. If there is no retention on stationary phase, there is no separation
What is the difference between low pressure and high pressure gradient HPLC?
In a high pressure gradient pump, each different mobile phase is delivered by an individual pump head and then the mobile phases are mixed at the pump outlet. In a low pressure gradient pump, different mobile phases are mixed using a valve before entering the pump head. As a result of the fact that the low-pressure gradient design uses only one pump head, it is of lower cost. It can also use more types of mobile phase without significant increase of cost. Since solvent mixing point is much closer to the column head in the high-pressure gradient design, it provides a much faster gradient. This is measured using delay volume. The value can be 50-300 uL for high pressure gradient pump and can be 2 to 3 times larger for a low pressure gradient pump. A small delay volume is important when the analysis time is short or the flow rate is low. If the delay volume is too large, it become impossible to obtain reproducible gradient run since the planed composition cannot reach the column head before a run is finished.
What is the H.P.L.C. chromatography?
HPLC stands for high performance liquid chromatography. It is a liquid chromatography which involves the separation of the compounds on the basis of their polarity. It is used to analyze, identify, purify & quantify the compounds.
How does chiral Hplc work?
As a very crude analogy, think of a playground slide with dents in it that are the size and shape of a left shoe print. If we put some shoes at the top and let them slide down, the left shoes will be more likely to get stuck in the dents than the right shoes (which don't fit as well and therefore slide over them more easily).
How do you change from reversed phase chromatography to normal phase chromatography?
How do you change from reversed phase chromatography to normal phase chromatography? answer:Water -------> Ethanol ---------> Acetone -----> Ethyl acetate ------>Chloroform ------->HeptaneHow to Change from normal phase to reversed phase chromatography?Heptane ------->Chloroform -------> Ethyl acetate ---->Acetone --------->ethanol -------> WaterMohammad Abdel Qader (Mousa)Lab. SupervisorChemical , Biological and Drug Analysis CenterAn-Najah National University.Nablus Palestinezawatehm@gmail.com 1)To ues reverse phase chromatography solvents like:-Acetonitrile,Methanol in HPLC Grade 2) To use normal phase chromatography sovents like:-Iso propyl alcohol,n-Haxane HPLC Grade
What affects chromotography?
Paper Chromatography is based on two phases i.e stationary phase & mobile phase. The mixture we use to separate or purify is a stationary phase that we put onto paper (which is usually Watmann's chromatographic paper #1 ) while the other solvent in tank is mobile phase (e.g. gasoline, water, ethanol etc.)Thus it depends upon chemical compositions of stationary phase & mobile phase.
How do you use resolution factor in HPLC?
resolution factor
What would you use in a paper chromatography?
We use several things such as stationary phase which is a paper, mobile phase according to your solute and the mixture to be analysed. All these are placed in a closed chamber.
Why water is not used in normal phase analysis?
In normal-phase chromatography, the stationary phase is polar and the mobile phase is a mixture of non-polar solvents such as hexane and slightly more polar solvents such as isopropanol. water is the most polar solvent of all solvents. If you use water as a mobile phase, the polar analytes will remain dissolved in water and there will be no retention of analytes on the stationary phase. If there is no retention on stationary phase, there is no separation
How do you use gradient in a sentence?
The gradient of the line was two-thirds.
