pic reagent
Posted: Sun Nov 11, 2007 1:42 pm
Hi can anyone tell me what PIC reagent is and what the initials stand for.
Many thanks Liv
Many thanks Liv
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pic reagent
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Posted: Sun Nov 11, 2007 3:18 pm
Paired Ion Chromatography. PIC reagents can be purchased from Waters.
Posted: Sun Nov 11, 2007 4:05 pm
Olivia - Paired Ion Chromatography is Waters' tradename, this technique is also called Ion Pair Chromatography. So you can purchase reagents from either Waters or elsewhere.
thank you
Posted: Sun Nov 11, 2007 11:25 pm
Many thanks
Liv
Liv
Posted: Mon Nov 12, 2007 2:21 pm
PIC or IPC reagents are phase modifiers, usually sodium salts of carboxilic acids. It is a technique used to "deionize" polar compounds - such as amines - and increase their retention in reversed phase chromatography.
Posted: Mon Nov 12, 2007 2:38 pm
You mean I suppose: sodium salts of alkyl sulfonic acids?PIC or IPC reagents are phase modifiers, usually sodium salts of carboxilic acids. It is a technique used to "deionize" polar compounds - such as amines - and increase their retention in reversed phase chromatography.
Regards
Posted: Mon Nov 12, 2007 2:40 pm
Exactly! Sorry fo mispelling but my "basic chemistry english" is a bit rusty! 
Posted: Mon Nov 12, 2007 8:52 pm
I'm probably being picky, but...
I believe PIC As are tetrabutylammonium hydrogen sulphate ( low UV ), or tetrabutyl ammonium phosphate ( standard form ), and the PIC B5-B8 are the alkane sulphonic acids. Not sure of difference between Low UV and standard form for PIC Bs.
I'm not sure they are just the sodium salts, because I once used a PIC reagent and the equivalent sodium salt from a different supplier, and the retention was different. I didn't investigate further.
Bruce Hamilton
I believe PIC As are tetrabutylammonium hydrogen sulphate ( low UV ), or tetrabutyl ammonium phosphate ( standard form ), and the PIC B5-B8 are the alkane sulphonic acids. Not sure of difference between Low UV and standard form for PIC Bs.
I'm not sure they are just the sodium salts, because I once used a PIC reagent and the equivalent sodium salt from a different supplier, and the retention was different. I didn't investigate further.
Bruce Hamilton
Posted: Mon Nov 12, 2007 10:01 pm
Bruce:
You are absolutely correct. I used this stuff when I worked for Waters in mid-80s and didn't research before posting.
In fact PIC A - for acids - is an tetrabutylammonium salt and PC B's - for bases - are alkane (B5-penta to B8-octa) sulphonic acids.
Of course Waters use quite pure preparations at adequate concentrations, but you must obtain the same results using the same compunds from any other source.
I had customers that used PIC reagents and them moved to do their own with same success. Anyway, due to new chemistries in RPLC, PIC is becoming less and less popular.
You are absolutely correct. I used this stuff when I worked for Waters in mid-80s and didn't research before posting.
In fact PIC A - for acids - is an tetrabutylammonium salt and PC B's - for bases - are alkane (B5-penta to B8-octa) sulphonic acids.
Of course Waters use quite pure preparations at adequate concentrations, but you must obtain the same results using the same compunds from any other source.
I had customers that used PIC reagents and them moved to do their own with same success. Anyway, due to new chemistries in RPLC, PIC is becoming less and less popular.