Note -- Do not intrupt an Experiment in Progress. Are both the computer and instrument turned on and running? Most often the screen saver will be displayed. The pump must be turned on.
Note that it says, "Fill Out the Login Notebook". Make an entry in the Logbook to show the the date, time, user name, and what sample(s) were analyzed. Make a note of any problems with the instrument. The Login notebook records all analysis performed by the instrument. It is very useful for tuning and maintenance purposes and must be kept up to date. Instrument logbooks may not be used as scratch paper.
Check that both the PNMR and NUTS programs are running on the computer, look at the Windows95 task bar at the bottom of the screen to see if they are present. If these programs are not running, or only one is running, or multiple copies are running, shutdown each program and re-start the computer.
Instrument Optminization -- In the sample rack behind the magnet there is a sealed NMR tube containing 5% ethylbenzene (EtBz) dissolved in CDCl3 with 1% tetramethylsilane (TMS). This is a reference standard and is used as an instrument performance testing sample. Always check the spectrum of EtBz before analyzing an unknown sample. This will insure the optimum performance. If the instrument gives a good spectrum with EtBz, but the unknown sample has a poor spectra prepare the sample again. If EtBz spectrum is poor then the instrument in not properly adjusted.
Load the ethylbenzene test sample. Click on the PNMR window and look at the data acquisition settings list.If necessary, set the data acquisition parameters to the default values. The following are typical values. For 1-D proton analysis there is no second dimension.
Type: ZG and press the Enter key. The computer screen will switch to acquisition mode and will display the FID during acquisition. Watch the PNMR window, and wait until the message window in the top right corner of the screen disappears before attempting to enter any further commands into either PNMR or NUTS.
Click on the NUTS window. Note that there may or may not already be a spectrum displayed in the window. If a spectrum is displayed, it is from the previous acquisition. To read in new data, use the A1 link-keys (press the 'a' key and then press the '1' key but don't press the Enter key)or use Ctrl plus the F2 key to process the spectra.
The new EtBz spectrum is displayed. If the peaks are pointing 'down', autophase the spectrum using the AP command (press the 'a' key and then press the 'p' key but don't press the Enter key).
Adjusting the Offset -- Look at the spectrum and verify that the TMS peak is within -5.5 to -6.5 PPM. If not, adjust the OFFSET in PNMR. First find the current value for the TMS peak in the NUTS window and apply the value in PNRM and obtain the FID again. Continue adjusting the OFFSET and re-acquiring the sample until the TMS peak is within the target range.
Check the Shim Settings -- Use the ZOOM mode to examine the TMS peak, looking for splitting near the apex. If the shimming is OK, there should be no peak splitting evident. If the TMS peak is split, run the basic shimming routine. Exit the ZOOM mode by centering the cursor in the NUTS window and pressing 'Enter'. Press Alt_V_R to return to full screen view.
Run the EtBz Test Sample Again -- Re-analyze the EtBz sample. Use the A1 link to look at the spectrum. Examine the TMS peak again using ZOOM mode. If the TMS peak is OK, use Ctrl-F1 to process the data (press and hold the Ctrl key, then press the F1 function key, then release both keys). This starts a macro automatically process the spectrum, integrate the peaks, format the printout, and allows you to enter a user name, the date, and the sample type, before printing the spectrum. After entering name, etc., click the ok button to send the output to the printer. If another window asks where to send the output (a printer dialog box) click ok, and the printer will start to print. Or use Ctrl-F2 to precess data but without printing.
Look at the screen and verify that the TMS peak appears at 0 PPM. Look at a typical EtBz spectrum in NUTS; it will have characteristics like the spectrum shown below. There will be what appears to be 'splitting' of the quartet and triplet in the Nuts spectrum of EtBz.
Note that integration and peak picking parameters are discussed in detail in the NUTS program section and not critical for optimization using EtBz (ethylbenzene).
That's all there is to it!
The NMR is operating properly and ready to analyze samples.
