(These instructions assume you are familiar with basic Macintosh procedures, if you are not, see a Macintosh manual or the tutorial which is on most Macintosh computers. Throughout the following, MB means mouse button.)
MacNMR startup
Go to the MacNMRGN folder (it will usually be open on the desktop, if it is not open, move the cursor to the MacNMRGN folder icon at the upper right area of the desktop and click twice).
Open your lab folder. Open the H1setup file (if your lab folder does not have a H1setup file, find one in the setup filesgn folder) this will start MacNMR, the NMR acquisition and processing program, and load standard parameters. If you get a file locked message, move the cursor to OK and click the mouse button (MB).
Changing the Sample
Move the cursor to the Console Button (the third icon from the left near the top of the MacNMR window), click the MB. Move the cursor to the AIR Button, click the MB. Move the cursor to the EJECT Button, click the MB. The NMR sample and spinner will be blown to the top of the magnet. Remove the sample and spinner from the magnet and remove the sample from the spinner. Place your sample in the spinner (the top of the tube should be coming out of the end of the spinner that has the black band) and use the clear plastic cylinder located on the right console cabinet to position the tube properly in the spinner. Put the sample and spinner in the top of the magnet and move the cursor to the LOAD Button, click the MB. The spinner rate in hertz is the value following the word rate in the current window, the rate should be between 15 and 30 after the sample has been in the magnet for a minute. The Spinner value should be set to 1200. If you need to adjust the spinner air flow, open the left door of the right console cabinet and locate the SPINNER AIR valve at the bottom. Adjust this valve very slowly to change the sample spin rate.
Locking and Shimming
Move the cursor to the Console Button and click the MB. Move the cursor to the SHIM Button (upper left section of the Console window) and click the MB. Move the cursor to the Load Shims Button and click the MB. A new window will pop up, move the cursor to 5mm current and click the MB. Move the cursor to the Open Button in the same window and click the MB. Move the cursor to the LOCK Button at the upper left and click the MB. Select your lock solvent from the upper left pop up menu. If your solvent is not in the list, find the appropriate reference ppm on the list located on the Rm. 106 door and enter it in the reference ppm box. Set # of points to 512, set sweep width to 512. Move the cursor to the SWEEP Button and click the MB. You will see two lock signals (red and green), one should be the mirror image of the other. The left side of the largest amplitude peak of the red signal should be positive. Adjust the Lock PH (phase) value if the swept signal does not satisfy the conditions in the previous two sentences. The position about which the signals are mirror images should be the central vertical blue line. The signal position can be adjusted with the Z0 Offset. When the Lock PH and Z0 Offset are properly adjusted, lock the spectrometer by moving the cursor to the LOCK Button and clicking the MB. The button immediately above the LOCK Button should be set to Lock fast. Adjust Lock RX so that the lock level is near 80 (there are lock meters on the left side of the Lock window and on the console near the keyboard). Appropriate values for the Lock TR and Lock RX are approximately 110 and 650 respectively. These values depend on lock solvent. If the lock level oscillates regularly 10 units or more, decrease Lock TR.
Move the cursor to the SHIM Button and click the MB. Move the cursor to Use Knobs and click the MB. Move the cursor to Coarse Z1 in the Knob A area and click the MB. Move the cursor to Coarse Z2 in the Knob B area and click the MB. The A and B knobs are located behind the keyboard and to the right, adjust these knobs so that the lock level is maximized. Move the cursor to Coarse Z3 in the Knob B area and click the MB. Again adjust the knobs until the lock level is maximized. Finally, move the cursor to Z1 in the Knob A area and click the MB, move the cursor to Z2 in the Knob B area and click the MB. Adjust the knobs until the lock level is maximized. Move the cursor to Return and Set and click the MB. Move the cursor to Lock fast, hold down the mouse button and drag to Lock slow. Move the cursor to Exit and click the MB.
Adjusting the Receiver Gain
Hold down the apple key and enter z to collect a single scan. The amplitude of the free induction decay (FID) can be measured in bits. There are several dotted horizontal lines on the screen. Towards the top of the screen, below the top dotted horizontal line is a number followed by the word "bits", this is the line amplitude (ie. 10 bits). Each successively lower line is one bit less until one gets to the 0 bits line (the central dotted horizontal line) which is labeled. After one scan, the initial part (which is also the largest part) of the FID should be between 8 and 10.5 bits. If the FID is too small, move the cursor to the Dashboard Button, the top left icon in the current window, and click the MB. Increase the RCVR gain value. If part of the FID is near the 11 bit line, decrease RCVR gain. Collect another one scan FID and check the FID amplitude. Adjust the RCVR gain until the one scan FID amplitude is between 8 and 10.5 bits.
Collecting and Processing the Spectrum
Open the Dashboard by moving the cursor to the Dashboard Button (top left icon in the MacNMR window). Change the Scans 1D value to 16. Hold down the apple key and enter z to collect 16 scans. Move the cursor to the Commands menu item at the top of the screen. Hold the mouse button down and drag to 1DFT, then release the mouse button. The FID will be converted to a frequency domain spectrum. See pages 4-11 to 4-14 of the MacNMR 5.1 manual for information on viewing and altering the processing commands.
Phase Adjustment
Move the cursor to the Option menu item at the top of the screen. Hold the MB down and drag to Phase Adjustment, release the MB. Move the cursor to the highest ppm peak on the spectrum (the furthest to the left) and click the MB. Move the cursor to the number just to the right of Pivot Point and click the MB. Adjust the Phase 0 setting so that the highest ppm peak has a symmetric shape and all the peak intensity is above the baseline. Phase 0 can to changed by moving the slider or clicking on the up or down arrows just below Phase 0. Adjust the phase of the rest of the spectrum by changing the Phase 1 value. Phase 1 can be changed by using the slider and arrows to the right of the analogous Phase 0 controls. When the phase is properly adjusted, move the cursor to OK and click the MB.
Chemical Shift Referencing and Axis Appearance
Zoom on a peak that has a known chemical shift. To zoom, move the cursor to one zoom region boundary, hold the mouse button down and drag to the other boundary, release the mouse button. The zoom region will be black. Move the cursor inside the zoom region and click the MB to fill the window with the zoom region. Move the cursor to the center of the peak and click the MB. Move the cursor to the Display menu item at the top of the screen and hold down the MB. Drag to Set Reference and release the MB. Move the cursor to ppm in the popup box and click the MB; enter the chemical shift ppm value followed by return.
The axis appearance may be changed by moving the cursor to the axis and clicking the MB twice. A popup dialog box appears that can be used to change the appearance of several axis items including units, tick marks, and label precision.
Peak Picking
Move the cursor to the Option menu item at the top of the screen, hold the MB down and drag to Peak Pick, release the mouse button. Zoom on the smallest peak that you wish to pick. See Chemical Shift Referencing above for zooming instructions. Move the cursor to the center of the smallest peak that you wish to pick and click the MB. Several parameters associated with the cursor position will be displayed near the top of the screen, including the spectral amplitude (amp). Move the mouse to the number to the right of Level and click the MB twice. Enter the amp value followed by return. The top and bottom of the black horizontal area is the peak pick threshold. Move the cursor to the spectrum baseline and click the MB, note the amplitude value near the top of the screen. Repeat this two or three times and note the maximum amplitude value. Move the cursor to the number to the right of Noise and click the MB twice. Enter the noise maximum amplitude value followed by return. Move the cursor to Label Peaks and make sure there is a X in the box to the left by clicking the mouse if necessary. Move the cursor to Apply and click the MB to pick the peaks.
Integration
Move the cursor to the Option menu item at the top of the screen, hold down the MB down and drag to Integral, release the MB. Zoom on the region of the spectrum that contains the peaks which you wish to integrate. See Chemical Shift Referencing above for zooming instructions. Move the cursor to the integral sign at the top left of the spectrum window, the cursor will change to a hand. Hold the MB down and drag an integral to a peak; repeat this for each peak that you wish to integrate. Move the cursor to the middle of an integral of known intensity (an integral where you know the number of protons). Adjust the appearance of the integral by moving the cursor to the center of the integral and clicking the MB, an adjustment box will appear. The left or right integral boundaries may be changed by moving the hand to the small box in the lower left or right of the integral adjustment box, holding down the MB and dragging to the new boundary. Move the hand to the upper right box in the integral adjustment box. The slope can be changed by holding down the MB and dragging. The curvature and multiplier can be changed by holding down the option or apple keys, respectively, holding down the MB and dragging. More than one integral box can be made active by holding down the shift key, moving the cursor to the integral and clicking. Any integral adjustments will then be applied to all active integrals. Integral curvature and slope should be adjusted so that the regions of the integral over the baseline are flat. Move the cursor to the middle of an integral and double click the mouse, an Integral Information window will appear. Set the Assigned Value to the known number of protons. You also may want to note the Multiplier value and set all other integral Multiplier values to the same value.
Plotting
Move the cursor to File at the top of the screen. Hold the MB down and drag to Page Setup, move the cursor to the landscape orientation icon (the right most of the two Orientation icons) and click the MB. Move the cursor to OK and click the MB. Move the cursor to File at the top of the screen again, hold down the MB and drag to Print, then drag right to Spectrum and release the MB. The layout of the plot will appear. Move the cursor to the Page Preview button and click the MB, you will see exactly how your plot will appear. Click the MB again to return to the plot layout and dialog window. All of the labeled windows can be moved and resized or removed entirely from the plot by dragging outside the dark black border. Put the cursor inside a window, hold down the MB and drag to move the window. Put the cursor in one of the small dark boxes just inside the window boundary, hold down the MB and drag to change the window size. When you are satisfied with the appearance of your plot, move the cursor to the OK button and click the MB to make a hard copy plot.