Chromatography Forum

genetics approaches. Gene expression pro- mosome in this way, in effect giving the cardiovascular disease. Egr-1 is an essen
.., i have been reading this novel book about the famous TWILIGHT stuff. I love the movie at first but when I came to read the book I was really disappointed because of there are lot of
ages you to sit calmly, be mindful, and enjoy your- many cocktails, from Shirley Temples to Tequila 2 In a large bowl, combine the salmon, bread crumbs, oats, onions, dill, parsley, paprika
When you're doing your screen captures, are you using full screen, or a reduced size? I'm suspecting a reduced size, since the outcome is bad If your monitor screen's full resolution is say 1280 x 80

I should add that the mobile phase contained 10% acetonitrile at all times to reduce hydrophobic effects. However, perhaps 10% isn't enough, and there is a hydrophobic retention mechanism in addition to ion exchange.

You are using two completely different columns with completely different pore sizes. The 4.6 mm i.d. column contains 500 A packing, while the 2.1 mm column contains a 1500 A packing. My bet is that the later elution on the 4.6 mm column is for the most part due to the smaller pore size, which results in a roughly 3-fold higher surface area and thus larger retention.

There could be other factors also, but you did not give the complete method, incluing the flow rates for the two columns. However, the pore size is likely to be the largest factor.

Thanks for the response.


The flow rate for the 2.1 mmID was 200 microliters/min

For the 4.6 mmID, 1 mL/min.

I should add that the separations were done on different instruments. The 4.6 mmID was run on a Perkin Elmer 410. The 2.1 mmID was run on HP 1050. Both runs at ambient temperature. Everything else (including mobile phase) identical.