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 90pw, 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 = 15s, p1 = 90 pulse width 

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

8. Design VDlist (can be named as desired), consisting of 10 sets of times, starting from 0.001s, 0.01s, 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90pw時 注意將D1 設長一些（記得先atmm)

3).  edc   （建立新檔案)

4).   Select  ACQUPARS

5).  將數據維度從 1 維換至 2 維

6).  選 pulprog＝t1ir,  set 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 

     ( 15s 為示意值, 假設 T1 為 3s )

8).  設計VDlist（可自行命名）其內計有10組時間、 前面數值由 0.001s,  0.01s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 = 5T 1