Understanding the structural complexity of dissolved organic matter: isomeric diversity. (28th May 2019)

• Record Type: Journal Article
• Authors: Leyva, Dennys; Tose, Lilian V.; Porter, Jacob; Wolff, Jeremy; Jaffé, Rudolf; Fernandez-Lima, Francisco
• Is Part Of: Faraday discussions. Volume 218(2019)
• Page Start: 431
• Page End: 440
• Publication Date: 2019-05-28
• Subjects: Chemistry -- Periodicals; Metallurgy -- Periodicals; Electrochemistry -- Periodicals; 540
• DOI: 10.1039/c8fd00221e
• Languages: English
• ISSNs: 1359-6640

Abstract

Abstract : In the present work, the advantages of ESI-TIMS-FT-ICR MS to address the isomeric content of dissolved organic matter are studied. Abstract : In the present work, the advantages of ESI-TIMS-FT-ICR MS to address the isomeric content of dissolved organic matter are studied. While the MS spectra allowed the observation of a high number of peaks ( e.g., PAN-L: 5004 and PAN-S: 4660), over 4× features were observed in the IMS-MS domain ( e.g., PAN-L: 22 015 and PAN-S: 20 954). Assuming a total general formula of C x H y N0–3 O0–19 S0–1, 3066 and 2830 chemical assignments were made in a single infusion experiment for PAN-L and PAN-S, respectively. Most of the identified chemical compounds (∼80%) corresponded to highly conjugated oxygen compounds (O1 –O20 ). ESI-TIMS-FT-ICR MS provided a lower estimate of the number of structural and conformational isomers ( e.g., an average of 6–10 isomers per chemical formula were observed). Moreover, ESI-q-FT-ICR MS/MS at the level of nominal mass ( i.e., 1 Da isolation) allowed for further estimation of the number of isomers based on unique fragmentation patterns and core fragments; the later suggested that multiple structural isomers could have very closely related CCS. These studies demonstrate the need for ultrahigh resolution TIMS mobility scan functions ( e.g., R = 200–500) in addition to tandem MS/MS isolation strategies.