Chromatography Forum

Posted: **Wed Apr 15, 2009 11:58 pm**

Hi!
I need help!

IÂ´m develope a method for drug analisys, in the specificity test, matrix show a peak at 1.3 min. The drug show a peak at 7.3 min. different retention time but the response of matrix is higher. Can I use the matrix? I have to change it?

Thank you!

Posted: **Thu Apr 16, 2009 3:05 am**

So long as the matrix has no peak which overlaps your analyte, there is no problem.

Posted: **Thu Apr 16, 2009 2:23 pm**

Thank you Tom.

Posted: **Thu Apr 16, 2009 3:46 pm**

That means that I have to consider like noise?[/b]

Posted: **Thu Apr 16, 2009 8:11 pm**

No, it's entirely independent of noise.

Your matrix will almost always show some peaks. One of the reasons for demonstrating specificity is to show that none of those peaks interferes (overlaps) with your analyte. That's why you run a matrix blank and then a spiked matrix and you overlay the chromatograms. Here's an old (but good) example (an insect growth regulator in bovine manure):

Posted: **Thu Apr 16, 2009 8:44 pm**

Than you for your help!

Chromatography Forum

Matrix response higher than analyte!

Matrix response higher than analyte!