Please look at the following below attached file which may help you in your analysis.

Thanks

Mrs/Miss Kr,

There is very frequently unable to separate completely structurally very similar compounds even when there are used a set of sample pretreatment steps to such purpose.

Since; perhaps, you are interested in analysis of these analytes in urine, looking at your question, I would like to focus your attention on our own-authored (mine and my co-author's theory according to the authorship shown in the references, below) stochastic dynamic theory and model formulas for exact quantification of analytes in complex mixtures by mass spectrometry. They are capable of determining absolutely analytes even if they are not completely separated chromatographically. Our method has been tested, so far, on analytes in mixture at pg.(mL)-1 comncentration level showing chemometric coefficients of linear correlation between theory and experiment /r/ = 0.99997 - 1.

Please, concentrate on references [1,2].

[1] Stochastic Dynamic Mass Spectrometric Approach to Quantify Reserpine in Solution; Bojidarka Ivanova, Michael Spiteller Analytical Chemistry Letters, 10 (2020) 703-721; Received 13 Oct 2020, Accepted 16 Dec 2020, Published online: 28 Jan 2021 Download citation https://doi.org/10.1080/22297928.2020.1865834

[2] Steroids, 164 (2020) 108750 Stochastic dynamic mass spectrometric quantification of steroids in mixture — Part II; Bojidarka Ivanova, Michael Spiteller

Detail on its application to exact 3D structural determination can be found in reference [4].

Also, within the framework of our theory there can be determined even the exact 3D structures of your analytes, mass spectrometrically. The latter isses has been discussed in review-articles [3].

[3] Bojidarka Ivanova und Michael Spiteller A stochastic dynamic mass spectrometric diffusion method and its application to 3D structural analysis of the analytes; Reviews in Analytical Chemistry, 38 (2019) 20190003; DOI: https://doi.org/10.1515/revac-2019-0003

Hi

I think you need to make derivatives for one of your compounds so you isolated it.

one of them by esterification for the carboxyl group or the other way by adding a transition metal for complexation

Mr. Alshara,

Your comment on the discussion is highly meaningful.

There, however, lies the following question: Which metal ion should be used to coordinate selectively to both the ligands? A possible solution to such problem would be the ions of silver: AgI, AgII and AgIII-ions. Because of, the ions of silver have capability of coordinating chelately. Also, they are capable of forming coordination polymers.

Perhapy, mrs/miss Kr would be interested in our following works [1-5] devoted to coordination capability of ions of silver, if, of course, she decide to use such strategy to her research.

[1] Polyhedron, 30 (2011) 241-245, AgI and ZnII complexes with possible application as NLO materials – Crystal structures and properties; Bojidarka Ivanova, Michael Spiteller

[2] Polyhedron, 137 (2017) 256-264

On the nature of the coordination bonding of metal–organics for ions with the d10 electronic configuration – Experimental and theoretical analyses; Bojidarka Ivanova, Michael Spiteller

[3] Polyhedron, 30 (2011) 2564-2573

Gas-phase CT-stabilized Ag(I) and Zn(II) metal–organic complexes – Experimental versus theoretical study; Marc Lamshöft, Jürgen Storp, Bojidarka Ivanova, Michael Spiteller

[4] Journal of Molecular Liquids, 292 (2019) 111307

Stochastic dynamic electrospray ionization mass spectrometric diffusion parameters and 3D structural determination of complexes of AgI–ion – Experimental and theoretical treatment, Bojidarka Ivanova, Michael Spiteller

[5] Bojidarka Ivanova, Michael Spiteller, Molecular structure and properties of silver (I/II/III) containing organometallics, 2011, GRIN Verlag, Muenchen, pp. 1-125; ISBN (eBook) 9783668042391

Dear Aida Kr thank you for your interesting technical question. In addition to the valuable references provided by Isam Eldin Hussein Elgailani please also have a look at the following potentially useful article:

Ultra-High-Performance Liquid Chromatography-Isotope Dilution Tandem Mass Spectrometry for the Determination of Phthalate Secondary Metabolites in Human Serum Based on Solid-Phase Extraction

https://academic.oup.com/jaoac/article-pdf/102/1/271/32428869/jaoac0271.pdf

(see attached)