Column chemistry flatters or punishes a figure like this. A core-shell column at this gradient resolves the close-eluting family that a fully porous 5 µm bed merges, so 99.92 % here is a harder number than the same figure from a coarser column.
c18_2p6
Column chemistry. 2.6 µm core-shell vs 5 µm fully porous, and when it matters.
Section 1
Contribution
Both submits records and annotates other people's.
Records submitted
18
n=18
Annotations
229
n=229
Median purity submitted
99.00%
n=18
Suppliers covered
13
n=18
Section 2
Records submitted
A submitter chose to buy this material and to pay for this assay. That choice is the selection mechanism behind the whole index and it is not random.
Section 3
Annotations
Signed technical comments on records. The index does not moderate annotations for agreement with its own arithmetic, and several of these disagree with it. Where a handle has made the same point on several records, one instance is shown and the rest are reachable from the records themselves.
Core-shell packing at 2.6 µm gains roughly 40 % in resolution over a 5 µm fully porous bed at the same length and pressure. On a pair this close, that is the difference between two peaks and one.
Column chemistry flatters or punishes a figure like this. A core-shell column at this gradient resolves the close-eluting family that a fully porous 5 µm bed merges, so 99.37 % here is a harder number than the same figure from a coarser column.
Column chemistry flatters or punishes a figure like this. A core-shell column at this gradient resolves the close-eluting family that a fully porous 5 µm bed merges, so 99.93 % here is a harder number than the same figure from a coarser column.
Column chemistry flatters or punishes a figure like this. A core-shell column at this gradient resolves the close-eluting family that a fully porous 5 µm bed merges, so 99.58 % here is a harder number than the same figure from a coarser column.
Column chemistry moves retention more than anything else on the list. A C18 from a different manufacturer with different end-capping will shift a peptide by a minute without any of it being a finding.
A short gradient on a high-efficiency column can outperform a long one on a coarse column. Method length alone is not a quality ranking and the index does not treat it as one.
Doubling column length gains 40 % resolution and doubles the run. On a routine release method that trade is usually declined, and the certificate should say which method was run.
Column chemistry flatters or punishes a figure like this. A core-shell column at this gradient resolves the close-eluting family that a fully porous 5 µm bed merges, so 99.80 % here is a harder number than the same figure from a coarser column.
Column chemistry flatters or punishes a figure like this. A core-shell column at this gradient resolves the close-eluting family that a fully porous 5 µm bed merges, so 99.55 % here is a harder number than the same figure from a coarser column.
The resolution figure sits in the system-suitability block with no PASS or FAIL beside it. That is deliberate: the index reports it and adjudicates nothing against it.
Column chemistry flatters or punishes a figure like this. A core-shell column at this gradient resolves the close-eluting family that a fully porous 5 µm bed merges, so 99.70 % here is a harder number than the same figure from a coarser column.
Showing 12 distinct comments of 229 annotations by this handle.