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Why should you not change solvents abruptly when running a column?
Wiki User
∙ 10y ago
the mixing of the two solvents can create heat and lead to a bad separation.
Wiki User
∙ 10y ago
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How do you distinguised np-hplc and rp-hplc?
NP-HPLC is "Normal Phase" HPLC, wherein the solvents used are less polar than the substrate in the HPLC column (e.g. using hexane or dichloromethane with a silica HPLC column). RP-HPLC is "Reverse-Phase" HPLC, wherein the solvents used are more polar than the substrate in the HPLC column (e.g. using Water and Methanol with a octadecylsilane (ODS or C18) column).
Why are the plates in column chromatography called 'theoretical plates'?
The number of theoretical plates in a chromatography column is a measure of how "long" the column is - how well it separates. A "short" column will only separate large or heavy molecules, and the medium and light stuff is still mixed together in the last band. A "long" column will separate the little stuff better because there are more theorectical plates. Picture a stack of sieves with smaller and smaller holes as the column gets "longer" and you've got the idea. This "length" has virtually nothing to do with the physical length of the separating column. It is a function of the packing materials and solvents used during a separation.
What is meant by constant molal overflow?
Constant molal overflow is a term used in binary distillation. When a 2 component mixture is being separated in a distillation column,the assumption of constant molal overflow means assuming that both components have the same enthalpy. It assumes that one mole of component 1 when it condenses will vapourise 1 mole of component 2,also assumes no heat loss from the column. Can be wildly innacurate,particularly with separating organic solvents,and water. Water has a uniquely high enthalpy,often 5-6 times higer than the organic solvents.
How much dmso should be used for a c-18 hplc column to knock out everything retained in the column?
Depends on the column..... For a regular C18, try running 10% methanol through and then full-loop injections of 50% DMSO repeatedly until you're happy with the result. Also, reduce the run-time. For me, 3 minutes for a 2x50mm.
Would you that mixing gases is a reversible change?
It isn't easily reversible but, it is reversible. You can use a molecular sieve or a distillation column to separate them.
What would happen to the cell reference if you were to copy the formula equals A245 one column to the right?
It would change the column reference by one column and become:=B245It would change the column reference by one column and become:=B245It would change the column reference by one column and become:=B245It would change the column reference by one column and become:=B245It would change the column reference by one column and become:=B245It would change the column reference by one column and become:=B245It would change the column reference by one column and become:=B245It would change the column reference by one column and become:=B245It would change the column reference by one column and become:=B245It would change the column reference by one column and become:=B245It would change the column reference by one column and become:=B245
How do you distinguised np-hplc and rp-hplc?
NP-HPLC is "Normal Phase" HPLC, wherein the solvents used are less polar than the substrate in the HPLC column (e.g. using hexane or dichloromethane with a silica HPLC column). RP-HPLC is "Reverse-Phase" HPLC, wherein the solvents used are more polar than the substrate in the HPLC column (e.g. using Water and Methanol with a octadecylsilane (ODS or C18) column).
What does a spilt double arrow allow you to do when positioned between two column or row heading?
It enables you to change the width of a column, or the height of a row. It changes the width of the column to the left or the height of the row above.It enables you to change the width of a column, or the height of a row. It changes the width of the column to the left or the height of the row above.It enables you to change the width of a column, or the height of a row. It changes the width of the column to the left or the height of the row above.It enables you to change the width of a column, or the height of a row. It changes the width of the column to the left or the height of the row above.It enables you to change the width of a column, or the height of a row. It changes the width of the column to the left or the height of the row above.It enables you to change the width of a column, or the height of a row. It changes the width of the column to the left or the height of the row above.It enables you to change the width of a column, or the height of a row. It changes the width of the column to the left or the height of the row above.It enables you to change the width of a column, or the height of a row. It changes the width of the column to the left or the height of the row above.It enables you to change the width of a column, or the height of a row. It changes the width of the column to the left or the height of the row above.It enables you to change the width of a column, or the height of a row. It changes the width of the column to the left or the height of the row above.It enables you to change the width of a column, or the height of a row. It changes the width of the column to the left or the height of the row above.
How do you Change the with?
How do you change the width of a column in excel
Which is a column running up and down the periodic table?
cluster
Why will a column will not change during the copy process?
The source column (where you copy from) will remain the same, but the target column (where you paste to) will change. That is the function of copy. If you are unable to copy to a column, check to ensure protection is turned off.
What is a row of figures running down a page?
Figures running down a page is usually referred to as a column.
How do you change a light on a steering column in a 2006 Chevy truck?
How do change a light on a steering column in a 2006 chevy truck?
In excel 2007 what are the processes of adjusting the row and column portion of cell references?
If you have a cell address H12 and want to change the column, change the H to the letter of the column you want. If you want to change the row, change the 12 to the number of the row you want.
How do you change the width of column f so that the contents automatically fit within the column in excel?
Double click on between the heading for column F and column G. When you put the cursor there, it will change to a bar with arrows to the left and to the right.
What kind of adult have a spinal column running the length of the body?
snakes
What rhymes with blogger?
A jogger could be a blogger who writes a running column.
