Chromatography Forum

Pore size is a normal parameter of column,what does it mean?Some manufacturer develop non-pore particle packing,what's its advantage?Will it be a tendency of column parking?Can it repalce present packing?

Pore size is a normal parameter of column,what does it mean?

Here's a schematic diagram taken from our Fundamentals of HPLC course that should help to explain. The particle size is 10 μm, the average pore size is 10 nm (= 100 Ã…).

Some manufacturer develop non-pore particle packing,what's its advantage?

The advantage is basically faster mass transfer (better efficiency at high flow rates) because analyte molecules do not need to diffuse in and out of the pores. The disadvantage is greatly decreased retention and loading capacity, because most of the surface area of a porous material is inside the pores.

Will it be a tendency of column parking?

First of all, it's not an "all-or-nothing" proposition; there are also "superficially porous" / "pellicular" / "porous layer bead" packings which have a non-porous core surrounded by a porous layer, so you really have to consider a continuum from totally porous to totally non-porous with all variations in between. There's nothing really "new" in the concept; materials of all these types have been around for over 30 years, and will probably continue to be around for the next 30!

Can it repalce present packing?

Per the previous paragraph, non-porous materials are present packings. As with anything else, "the devil is in the details", and the tradeoffs among efficiency, retention, loading capacity, etc. must be considered in each case.

non-porous materials are present packings

So,can I classify present packing as porous and non-porous? Of course,the difference is only the pore size(the "absolute" non-porous packing is inexistence).
Some manufacturer produce a non-porous silica base to get faster mass transfer,then plus a pellicular or film to increase its retention and loading capacity, why do they not produce a packing having a suitable pore size to get a good balance between mass transfer and surface area straightly?

Another question,which field do non-porous packing applicate most?

ps:I am intreseted to column packing(LC column,especially),can you give me some advice about this? book,website,etc.Something basal and advanced is all I wanted.

So,can I classify present packing as porous and non-porous?

You can classify them in a variety of ways. As I indicated in my previous post, I tend to classify as porous, pellicular, and non-porous.

why do they not produce a packing having a suitable pore size to get a good balance between mass transfer and surface area straightly

That's exactly what they do. A large number of very smart people have worked in this area for over 40 years, and HPLC is far and away the most widely used instrumental analytical technique in the world; we must be doing something right!

Another question,which field do non-porous packing applicate most?

In general, for larger molecules (because they diffuse more slowly).

I am intreseted to column packing(LC column,especially),can you give me some advice about this? book,website,etc.Something basal and advanced is all I wanted

Get a copy of Uwe Neue's book:
HPLC Columns: Theory, Technology, and Practice