Chromatography Forum

hi

How is everyone

i have some Problem in HPLC
i am going to separate isoprapnol by use HPLC but i need to know retention time for isoprapnol ?

and can i use HPLC for separate isoprpanol ?

Thank s so much

and can i use HPLC for separate isoprpanol ?

What do you want to separate it from?

The retention time will depend on the conditions:
- what column packing?
- what mobile phase?
- what column dimensions?
- what flow rate?
- what temperature?

That said, gas chromatography would probably be a better choice.

[quote
That said, gas chromatography would probably be a better choice.

I agree.

Not an HPLC bob here so I am sticking my neck out a bit. What detector would you propose using: put another way I would not think IPA has much of a UV response...

Best regards,

AICMM

You would have to use RI detection, and a column such as the Biorad Aminex 87H to get retention. That column is capable of separating a wide range of small organic or large very polar compounds that are not retained on reverse phase columns. Check out their website (biorad.com) and look at the Aminex series of columns.

I'm guessing you either don't have GC available, or that the sample matrix is completely incompatible with GC. Or you have a sample you want to just filter and inject and not derivatize?

HPLC/RI isocratic systems with the Biorad 87H columns are easy to set up but there are limitations, for instance, the selectivity control on the 87H is very limited: all you can do is add small amount of modifier (acn) and the selectivity changes are minimal; or you change the pH of the eluent (dilute H2SO4). You're pretty much stuck with the "out of box" selectivity of the column. But the column is extremely rugged if you follow the operating guidelines and we've used them for decades (yes, the same column!) with good results.

and can i use HPLC for separate isoprpanol ?

What do you want to separate it from?

The retention time will depend on the conditions:
- what column packing?
- what mobile phase?
- what column dimensions?
- what flow rate?
- what temperature?

That said, gas chromatography would probably be a better choice.

thank s so much >>> but i need to Know What are the conditions suitable(in HPLC) for the separation in terms of the type column and temperature and mobile phase because I want separation of isopropanol as a standard material and I want to I know the time of retention.

[quote
That said, gas chromatography would probably be a better choice.

I agree.

thnk s so much but i have to use HPLC

Not an HPLC bob here so I am sticking my neck out a bit. What detector would you propose using: put another way I would not think IPA has much of a UV response...

Best regards,

AICMM

thank s so much

You would have to use RI detection, and a column such as the Biorad Aminex 87H to get retention. That column is capable of separating a wide range of small organic or large very polar compounds that are not retained on reverse phase columns. Check out their website (biorad.com) and look at the Aminex series of columns.

I'm guessing you either don't have GC available, or that the sample matrix is completely incompatible with GC. Or you have a sample you want to just filter and inject and not derivatize?

HPLC/RI isocratic systems with the Biorad 87H columns are easy to set up but there are limitations, for instance, the selectivity control on the 87H is very limited: all you can do is add small amount of modifier (acn) and the selectivity changes are minimal; or you change the pH of the eluent (dilute H2SO4). You're pretty much stuck with the "out of box" selectivity of the column. But the column is extremely rugged if you follow the operating guidelines and we've used them for decades (yes, the same column!) with good results.

Thank you very much for valuable information