Chromatography Forum

I am looking for RP HPLC method, using UV detector for lysine concentration determination. Now we are using EC for that, but sample prep is too complicated. Thank you.

What is your sample? There are several ways to do it through derivatization of Lys. Low wavelength UV will also work without derivatization if your sample is simple enough (which I doubt if you are saying that sample preparation is too complicated when using EC).

My sample has lipids, dextrose, API and lysine.
I use to use HPLC method for amino acids purity in a past, but forgot details. And I am not sure if I can use this method for my sample now.
I used Luna column, mobile phase A: phosphate buffer with ACN and mobile phase B: ACN or ACN+MeOH.

Ollysa,

You can use our mixed-mode Primesep columns for direct analysis of amino acids with UV detection. Your mobile phase will consist of ACN/water/acid (sulfuric, phosphoric acid and corresponding buffers at pH 2-3):

http://www.sielc.com/application_114.html
http://www.sielc.com/application_085.html
http://www.sielc.com/application_087.html
http://www.sielc.com/application_080.html
http://www.sielc.com/application_105.html

Contact me if you have any questions

P.S. if you API is basic or hydrophobic in nature you can use this approach to quantitate API and lysine in one run, Dextrose is not going to be retained and lypids can be trapped on a guard column similar to this approach:
http://www.sielc.com/pdf/SIELC_September_2004.pdf

yzelechonok,
Thank you. I will try it.

In your original conditions Lys would be eluted in the void volume. You can try the Primesep columns or ion pairing chromatography methods or...

Separation of basic amino acids (including lysine) on Unison UK-Amino:
http://www.silvertonesciences.com/files/TI329E.pdf

I have more one some try for you, I bilieve this method is more easyer....and flexible for you condiction...think about this..

Implementing stepwise solvent elution in sequential injection chromatography for fluorimetric determination of intracellular free amino acids in the microalgae Tetraselmis gracilis


doi:10.1016/j.physletb.2003.10.071