In case of HPLC coloums what is the difference Between C8 &
C18 coloums & how can we select difference type of coloums
like Inertial ODS , Hypersil BDS , ODS etc.?
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Answer / paresh jobanputtra, piramal(ah
in case of C8 column,C8 carbon chain is attached to the packing material
and in case of C18(ODS) column, C18 carbon chain is attached to the packeting material.
eg. OH
¡
OH-SI-O-C8 orC18
!
OH
Some names of specially treated stationary phases:suitable for separation of BASIC compds.
like Inertsil:"Inert towards bases"
BDS :"Base deactivated silica"
different make columns have different characteristics
like different Carbon load,Specific pore volume(empty spaces betn particles),Specific surface area,Ligand density etc.
If the carbon load is high it means specific pore volume is lesss so retained capability of packing material is high so capacity factor is high. so retemtion is better of this column.
and selection of column is depends on nature of product, and no of trials in developement.
Regards,
Paresh Jobanputtra.
| Is This Answer Correct ? | 26 Yes | 3 No |
HPLC in mainly two types of columns is used
These are (1)Normal phase columns
(2)Reverse phase columns
C18 And C8 COLUMNS both are reverse phase columns.
C18 columns is highly polar columns compare with C8 columns
C18 Column Structure is OH-Si-C18 linkage
C8 Column Structure is OH-Si-C8 linkage
These columns is depend up on the compound natchere
ODS means OCTA DECYLE SILANE. This types of columns
is used mainly acidic nacture compounds.
BDS means BASE DEACTIVATED SILANE. This types of columns
is used mainly basic nacture compounds.
| Is This Answer Correct ? | 19 Yes | 10 No |
Answer / pharmainterview
C8- C8 Carbon chain is attached to silica
c18- C18 Carbon chain is attached to silica.
There are many manufacturer who will prepare c8 or c18
column. Even though the basic concept is same for all,
there are some differences like
1.pore size
2.particle size
3.free silanol
4.end capping
5.silica purity etc
Based on our sample properties and suitability we can selct
a column after different trials.
Regards
pharmainterviewquestions.blogspot.in
| Is This Answer Correct ? | 9 Yes | 1 No |
I think both columns polar columns
BDS column based deactivedd silane this hair ph basic nature
ODS Column Octa decyle silane acetic nature ph 7 below
| Is This Answer Correct ? | 4 Yes | 6 No |
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