T1 expt

In quantitative NMR experiments, accurate integral values are required to deduce concentrations, reaction rates, etc. The measurement of T1 is necessary to determine the setting of D1.

Measurement of T1:

ACQU:

1. Mount the sample on a spinner, measure the depth, use the lift to place the sample in the magnet, lock, shim, atmm.

2. Measure the 90 - degree pulse width, when measuring 90 pw, make sure to set D1 longer (remember to atmm first).

3. edc (create a new file).

4. Select ACQUPARS.

5. Change the data dimension from 1D to 2D.

6. Choose pulprog = t1ir, set 1 td = 10, in F1 domain. (The number of td1 is the item of delay in vdlist).

7. Set D1 = 15 s, p1 = 90 pulse width 

(15 s is a nominal value, assuming T1 is 3 s).

8. Design VDlist (can be named as desired), consisting of 10 sets of times, starting from 0.001 s, 0.01 s, and increasing by multiples in between, with the last 3 sets of values being 3T1, 4T1, and 5T1.

9. rga, zg.

10. If the measured T1 value exceeds D1 / 5, recalibrate once more.

The measured T1 value can then be used for quantification. In quantitative experiments, D1 = 5T1.

定量 NMR 實驗中，需要準確的積分值以推算濃度、反應速率等，須量測 T1 以決定 D1 的設定。

T1的量測：

ACQU:

1 ).  樣品裝上 spinner，量好深度、用 lift 將樣品置入磁鐵中，lock, shim, atmm

2).  先量測 90 pulse width，在量測 90 pw 時注意將 D1 設長一些（記得先 atmm）

3).  edc（建立新檔案）

4).  選擇 ACQUPARS

5).  將數據維度從 1 維換至 2 維

6).  選 pulprog ＝ t1ir，設定 1 td ＝ 10，in F1 domain

（td1 的數目就是 vdlist 的 delay 的項次）

7).  設定 D1 = 15s,  p1 = 90 pulse width 

     ( 15 s 為示意值，假設 T1 為 3 s )

8).  設計 VDlist（可自行命名）其內計有 10 組時間、前面數值由 0.001 s, 0.01 s 開始，中間可用倍數增加、最後3組數值為

3T1、4T1 及 5T1

9).  rga, zg

10).  測出來的 T1 值若超過 D1 / 5，再回歸校正一次

測得的 T1 值就能用在定量上，定量實驗的 D1 = 5T1