All Questions
Tagged with chromatography purification
20
questions
1
vote
1
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127
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Making an UV inactive salt UV active during purification of charged anion with HILIC purification?
In the context of a purification setup I am asking myself the question: Can a UV inactive charged substance made be UV active by a counter ion that absorbs UV light during a column run?
If so, when no ...
- 799
2
votes
0
answers
80
views
When is chromatography regarded as a viable industrial purification strategy?
I understand the basics that chromatography is a fairly slow and expensive process compared to direct synthesis. When a synthesis route is not feasible, the economics become favorable. Not being in ...
- 651
2
votes
0
answers
64
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Mixture is eluted too early from alumina in flash column chromatography
I have recently tried to purify my reaction mixture by column chromatography. Because my reaction mixture had poor resolution in silica-based TLC, I used neutral alumina-based TLC plate. After I ...
- 1,101
1
vote
0
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385
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Activating alumina before column chromatography
Recently I synthesized some amine compounds, and because it showed better separation in the neutral alumina TLC plates than silica plates, I am planning to purify the reaction mixture using neutral ...
- 1,101
1
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0
answers
84
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Fragmentation behavior of spots in TLC
I tested multiple development using eluent condition hexane + 1% of ethyl acetate. Then I observed kind of fragmentation of spot.
I'm not sure, but I guess that successive spots are from the skyblue ...
- 1,101
2
votes
0
answers
809
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Using neutral or basic alumina in column chromatography for purification of amines
I am conducting a synthesis involving amines, and it is found that some spots still hardly moves from the starting point in spite of the dichloromethane 9:methanol 1 eluent condition. Addition of ...
- 1,101
1
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0
answers
19
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How can I determine the purity of an oligonucleotide solution?
After desalting an oligonucleotide via gel chromatography, I am left with (presumably) an oligonucleotide substance suspended in a buffer. What is the simplest way to verify the oligonucleotide's ...
- 151
2
votes
0
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314
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Analysis of reaction mixture by TLC and finding column chromatography condition
I am conducting an organic synthesis. Below is the TLC image.
I used dichloromethane:methanol:triethylamine=10:1:0.15 as eluent, but I stored it during 3 days, so it may be a little bit concentrated.
...
- 1,101
0
votes
1
answer
124
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Is it possible to functionalize silica gel as Activated Carbon can be? How?
Activated carbon and Silica gel both have a high surface area.
If I understand correctly it is possible to trap stuff inside activated charcoal pores to give it specific retention properties (by ...
- 1,097
5
votes
1
answer
314
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Purification of primary amines using Schiff base immobilization
I want to purify all primary amines containing compounds in a complex mixture (cell-extracted metabolites). I'm unaware of any published methods to do so. So I am thinking of making my own using a ...
1
vote
2
answers
1k
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Can separated and purified substances be obtained from a chromatogram?
I am studying chemistry, and I am learning about chromatography.
But I am confused about how chromatography is used to ‘separate and purify’ substances.
I have learnt about chromatography paper, ...
- 693
2
votes
1
answer
194
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Can we use HPLC to purify an organic reaction product?
I know HPLC is a form of column chromatography that uses high pressure to pump a sample mixture/eluent through a column. However, I'm not sure if this technique is being used to purify and isolate ...
- 23
1
vote
0
answers
54
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Change buffer in dialysis?
I have a protein that I purified in PBS buffer, pH 7. I will do dialysis to remove salt and will then further purify the protein with ion exchange chromatography.
I will need to use another buffer (...
- 11
1
vote
1
answer
1k
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In HPLC, how does column diameter affect the retention time?
I am using a smaller diameter column than my previous one keeping all other factors such as stationary phase, solvent, solvent gradient constant. (Obviously, flow rate will be less in smaller column). ...
- 157
3
votes
0
answers
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Purification of polar NHS esters
What are the options that I might be missing for the purification of a molecule with the following characteristic:
Contains an activated ester that reacts with water (NHS)
Reacts readily with ...
- 313