Using T-1 as a direct detection dimension in two-dimensional time-domain NMR experiments using CWFP regime

Author(s)

Monaretto, Tatiana ^[1] ; Montrazi, Elton Tadeu ^[2] ; Moraes, Tiago Bueno ^[2] ; Souza, Andre Alves ^[3] ; Rondeau-Mouro, Corinne ^[4] ; Colnago, Luiz Alberto ^[5]

Affiliation

^[1] Univ Sao Paulo, Inst Quim Sao Carlos, Av Trabalhador Sao Carlense 400, BR-13566590 Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, Inst Fis Sao Carlos, Av Trabalhador Sao Carlense 400, BR-13566590 Sao Carlos, SP - Brazil

^[3] Schlumberger Brazil Technol Integrat Ctr, Av Rep Chile, 330 Torre Oeste, 18 Andar, BR-20031170 Rio De Janeiro, RJ - Brazil

^[4] INRAE, UR OPAALE, 17 Ave Cucille, CS 64427, F-35044 Rennes - France

^[5] EMBRAPA Instrumentacao, Rua XV Novembro 1452, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: JOURNAL OF MAGNETIC RESONANCE; v. 311, FEB 2020.
• Web of Science Citations: 0

Abstract

The transverse relaxation time (T-2), measured with Carr-Purcell-Meiboom-Gill (CPMG) sequence, has been widely used to obtain the direct dimension data in two-dimension time domain NMR (2D TD-NMR). In this paper we are demonstrating that Continuous Wave Free Precession sequence, with low flip angle (CWFP-T-1), can be an alternative to CPMG as direct detection dimension. CWFP-T-1 is a fast single shot sequence, like CPMG, and yields an exponential signal governed predominantly by the longitudinal (T-1) relaxation time. To obtain the correlations between T-1 and T-2 (T-1 -T-2 maps) we are proposing the use of CPMG-CWFP-T-1 pulse sequence. In this sequence CPMG encodes T-2 information (indirect dimension) that modulates the CWFP-T-1 (direct dimension) signal amplitudes. CPMG-CWFP-T-1 experiments were compared with classical 2D sequences such as Saturation-Recovery-CPMG (SR-CPMG) and InversionRecovery-CPMG (IR-CPMG) sequence and yields similar results in phantom sample. The experimental time for the 2D sequences, using single scan, shows that SR-CPMG <= CPMG-CWFP-T-1 < IR-CPMG. Experimental and simulated results demonstrated that 2D-CPMG-CWFP-T-1 maps have higher resolution in T-1 dimension than the techniques that uses CPMG as direct dimension. CPMG-CWFP-T-1 sequence was also applied to study beef samples, and 2D maps showed higher resolution in the two fat signals than the classical IR-CPMG method. (C) 2019 Elsevier Inc. All rights reserved. (AU)

• FAPESP's process: 19/13656-8 - Development and application of nuclear magnetic resonance in products and agricultural processes
• Grantee: Luiz Alberto Colnago
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/12864-0 - Effect of NMR magnetic field in chemical reactions monitored NMR in situ
• Grantee: Luiz Alberto Colnago
• Support Opportunities: Regular Research Grants