- Don’t spin the sample, do topshim with X-Y… items instead. Run 1D PROTON first, and find proper o1, sw, and p1 by pulsecal.
- Load H1_CPMG_T2_hw ( using cpmg sequence) from …/par/user parameter folder, besides using most of the default parameters, update p1, o1, sw.
- (For the std CDCl3 sample in B500-Chewie) Try to use d1=20s (to 150s); d20=10ms (2*d20 = the fixed delay time between two 180° proton pluses in CPMG train; d20 should be << 1/J; but > 50*p2); ns=8 or 16.
- Edit vclist, and choose ncyc as even numbers, like 2, 20, 50, 100, 300, 400, 500, 700, 1000; and then set TD1 as the total number of ncycs in vclist (9 here).
- rga, expt (using expt to show the total nmr time will be shorter than the real total time), and zg.
Note:
- T2 delay time = ncyc*(2*d20 + p2); here p2 is 180° H1 pulse length.
- So the ncyc in vclist is corresponding to the T2 delay time as: 0.040052s, … 20.026s, (d20=10ms, p2=26us on B500-Chewie here).
Process with T1T2 Application:
- Do the calculations with Excel or manually and convert vclist’s ncyc into T2 delay time points with the above formula and save as “vdlist” filename inside the original data folder.
- Next, process T2 data just like T1’s. Be careful that:
- edp or select ProcPars, set SI for F1 to 9, but return to 16, since SI only choose next highest power of 2 for F1.
- Set SPECTYP to PSEUDO2D.
- xf2↙, .ph, select Rows button to do phase correction, save & exit, abs2↙,
- Applications → Dynamics → T1T2 → FID →Spectrum → 1
- Peaks/Ranges → Manual integration → define Ranges → integrate regions (choose more peaks…) → Export regions to Relaxation module and .ret.
- Go to Relaxation tab → check parameters (make sure to choose: uxnmrt2 as Function Type; vdlist as List Name; use intensity to fit, etc.) → press “>” to fitting, click full spectrum button, click lin; and then press “>>>” to fit all other peaks, then click “show report”, save into a text file in the original data folder.
Hongwei edited on 5/12/2023