500 MHz
spectrometer
user manual
may 2015
Sandrine Denis-Quanquin
500 MHz spectrometer
user manual
2015
1.
THE NMR SPECTROMETER ........................................................................................... 3
2.
MANUAL MODE / AUTOMATION .................................................................................... 5
2.1
2.2
2.3
3.
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
4.
4.1
4.2
4.3
4.4
4.5
SAMPLE CHANGER ............................................................................................................ 5
MANUAL MODE ................................................................................................................. 5
AUTOMATION .................................................................................................................... 5
PRELIMINARY SETTINGS ............................................................................................... 7
CREATION OF A NEW DATA SET ......................................................................................... 7
GETPROSOL ..................................................................................................................... 7
LOCK................................................................................................................................ 7
PROBE TUNING ................................................................................................................. 8
SHIM ................................................................................................................................ 9
GAIN .............................................................................................................................. 10
SOME INTERESTING ACQUISITION PARAMETERS ............................................................... 10
SOME IMPORTANT COMMANDS ........................................................................................ 11
SOME ROUTINE EXPERIMENTS .................................................................................. 12
WHICH 13C 1D TO CHOOSE? ............................................................................................ 12
HOW TO SUPPRESS A STRONG SOLVENT SIGNAL? ............................................................ 13
HOW TO CALIBRATE A 13C, 31P OR OTHER X SPECTRUM? ................................................. 13
«STANDARD» 2D EXPERIMENTS ...................................................................................... 14
SOME OTHER 2D ............................................................................................................. 15
5.
TOPSPIN 2.1 ................................................................................................................... 17
6.
PROCESSING OF 1D DATA .......................................................................................... 19
6.1
6.2
6.3
6.4
7.
7.1
7.2
7.3
SOME INTERESTING PROCESSING PARAMETERS ............................................................... 19
PHASE CORRECTION ....................................................................................................... 21
BASELINE CORRECTION .................................................................................................. 21
SPECTRUM CALIBRATION ................................................................................................ 22
PROCESSING OF 2D DATA .......................................................................................... 23
CONTOUR LEVELS ........................................................................................................... 23
PHASE CORRECTION ....................................................................................................... 23
1D PROJECTIONS ............................................................................................................ 24
8.
TROUBLESHOOTING .................................................................................................... 25
9.
INDEX ............................................................................................................................. 28
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1. THE NMR SPECTROMETER
• The 500 MHz NMR spectrometer is equipped with 2 probes
Ø BBO, a broadband direct probe with a 1H coil and a X coil for observation of nuclei in
which the resonance frequency is comprised between 15N and 31P.
Ø TXI, an inverse probe with 3 specific coils ( 1H,
13
C and 15N). This probe is particularly useful for
biological studies and is 2,5 times more sensitive
than BBO for proton observation. This is relevant
for experiments with a proton detection (COSY
and HSQC, HMBC...).
Intern coil
Extern coil
Observed nuclei
Probe tuning
Spinning?
BBO
X
1
H
1
H, 15N - 31P
automatic (>atma)
only for 1D spectra
TXI
1
H
13
C, 15N
1
H, 13C, 15N
manual (>wobb)
never
Rq: 19F can’t be observed with the
500MHz spectrometer
Comparison of the 500MHz probes an the 300MHz BBFO probe: sample= symetric molecule
MW= 1300 g.mol-1 , soluble in CDCl3, 3 mg in a tube ≈ 6 g.L-1 or 5 mM
300 MHz
500MHz BBO
500 MHz TXI
COSY
NS= 1 ➔ less than 5min
HSQC
NS= 4 or 8 ➔ 14 or 28min
NS= 1 ➔ less than
5min
NS= 2 or 4 ➔ 12 or
25min
NS= 8 ➔ 1h
NS= 2000 ➔ 1h30min
LESS THAN 3H
NS= 1 ➔ less than
5min
NS= 1 or 2 ➔ 6 or
12min
NS= 4 ➔ 25min
NS= 8000 ➔ 9h15min
for sensitive 2D!!!!
HMBC
decoupled
“totale”
13
C
NS= 16 ➔ 1h25min
NS= 8000 ➔ 9h15min
LESS THAN 12H!!!
• The 500MHz is also equipped with a temperature regulation unit (from -100 to +80°C).
For temperatures lower than 0°C the air inlet must be replaced by the liquid nitrogen
evaporator. A ceramic spinner and even a pyrex tube must be used for experiments with
large variations of temperature.
The BBO is the probe by default on the 500MHz, if the TXI is installed the message
“maintenance -->TXI” is mentionned on the online reservation page.
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• Standard parameters sets are copied in the «MANIPS MODELES» directory and may be
read with the command > rpar . You are strongly advised to start from these parameter
sets and then you may optimize them for your sample.
• The BSMS window may be used in manual mode for sample
spinning. Clicking on the yellow BSMS button in Topspin toolbar
will display the BSMS window like the one you are used to with
the 300 MHz.
• Each Topspin command may either be clicked or entered in the
pink command line or found in the upper menus/submenus. In this
manual I will show you the clickable buttons and commands to
enter (they will always be preceded by > )
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2. MANUAL MODE / AUTOMATION
2.1 Sample changer
ATTENTION check that the sample changer light is GREEN before
adding/taking a tube from the carousel.
WHITE light: automatic operation running, DO NOT TOUCH
BLUE light: carousel not in place
RED: technical problem
NEVER LEAVE AN EMPTY SPINNER IN THE CAROUSEL!!!
2.2 Manual mode
Check that no automation run is going on. If the automation window is opened, check that no
experiment is running and close the automation window (see next §). If an experiment is
running and IF IT IS YOUR SCHEDULED TIME, HALT the experiment and close the
automation window.
The command > sx 3
ejects the tube in case there is one in the magnet AND inserts the
tube at position 3... The carousel has a capacity of 16 samples, you can a tube at any
available position. ATTENTION if a tube is already in the magnet it will be ejected back to the
position IN FRONT of the nmr access!!!
The command > sx ej
ejects the tube from the magnet and put it back in its position.
2.3 Automation
Click on the green « PASSEUR » button to start the software IconNMR then click on
« Automation ».
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Select your name in the pop up window then OK.
Parameters: NS, D1…
In the IconNMR window you may schedule and set up the experiments.
First column is for the position number on the carousel. Double click for modification. Then
fill in the sample name (Name), the solvent and select the experiments to run. The
experiments named « la totale » consist in a 1D proton, a COSY, a decoupled carbon, an
HSQC and an HMBC. there is a variant with a udeft instead of the decoupled carbon. When
you select « la totale » the different experiments are automatically created with following
experiment numbers.
Some parameters may me optimized by clicking on the blue button (Par column).
You may edit the title (Title/Orig).
Data will be stored in th directory of the USER selected when starting IconNMR. If several
people want to scedule experiments they must change the USER (Change User)
Once the experiments are set up for the samples on the carousel click on Submit then on
Start (green « cogwheel » on the upper left corner of the window).
NB: you may add samples once the run is started.
If you want to modify a submited sample, first click cancel then edit.
The last sample is ejected at the end of the run.
IconNMR is configured to process the data (except from integration and pic peaking). Lock,
atma, rga and shims are automatically performed when necessary.
To stop IconNMR at the end of the run you need to be logued as the SER that started the
run. Do not save the set up. Close all IconNMR windows.
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3. PRELIMINARY SETTINGS
Whatever experiment you plan, it is strongly advised to always start with a proton
spectrum. A quick proton spectrum is useful to check that lock is ok, shims are good,
sample concentration is ok for the planned experiments...
3.1 Creation of a new data set
or >new
Change NAME and USER (your directory).
EXPNO is the number of the experiment. For
example with the sample «ananas» you may
create 1 - a proton dataset, 2 - a COSY, 3 an HSQC...
NB: the option «use current parameters»
creates an experiment identical as the one
you start from. Don’t change this option,
even if you want different parameters as the
modification will be saved.
To create a different experiment read the parameters afterwards with >rpar SDQ*
3.2 Getprosol
in the Acqupars window or >getprosol for each experiment!
This command reads pulse values associated with the probe in place. As these values are
probe dependent and may change along the years, it is ESSENTIAL that you make sure you
use the right pulses (length and power). The use of incorrect values may lead to a sensitivity
loss (pulses too weak) or to an error message stopping the acquisition (pulses too strong).
3.3 Lock
>lock and choose the appropriate solvent
once for each sample
The aim of the lock is to guarantee a stable magnetic field along the experiment.
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The lock system is a spectrometer in the spectrometer, dedicated to the observation of
deuterium. The system compares the solvent deuterium signal frequency with a theoretical
value and corrects the magnetic field strength accordingly. This correction is repeated at a
high frequency as long as the system is locked, thus compensating for the magnetic field
fluctuations.
Furthermore the lock system calibrates the spectrum with the solvent proton residual signal
chemical shift as a reference (NMR solvents are > 99,5% deuterated).
3.4 Probe tuning
>atma with BBO and >wobb with TXI
for each nucleus!
(be aware that TXI need to be manually tuned using the screws under the probe)
Each coil in the probe is a circuit «tuned» to the resonance frquency of the observed nucleus
(1H or X). Tuning the probe may be compared to tuning a radio receiver to a FM frequency.
A poor tuning leads to a sensitivity loss. Matching consists in adjusting the probe impedance
(resistance) until it matches that of the receiver circuit in the spectrometer. It should
guarantee a maximum transmission of the signal.
As electrical properties differ between solvents the probe must be tuned for each sample.
The X coil needs to be tuned just as much as the proton coil, especially with the BBO. The
previous user might have run a 31P spectrum and tuned the X coil for a maximal sensitivity at
202,4 MHz. If you forget to tune the probe and intent to run a 13C experiment frequency125,7MHz - you will barely see any signals...
The 2 yellow screws under the probe on the left are for
matching and tuning of the proton coil (use the rod hung to the
probe to screw/unscrew).
The tuning is optimal when there are only green diodes on the
grey box near the magnet or when the minimum of the curve on
the computer screen is on the red line i.e. tuned at the
resonance frequency of the observed nucleus.
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3.5 Shim
High resolution NMR experiments require a uniform magnetic field over the whole of the
sample volume that sits within the detecting coil. B0 being sensitive to many factors it must
be adjusted to obtain signals as narrow and symmetric as possible. To this end «shims»
coils are used. They carry electrical currents thus generating small local magnetic fields that
are tuned until they compensate B0 inhomogeneities.
An automatic program is used to shim: Topshim tunes shim
coils Z to Z5 routinely.
By default topshim is configured as follows: dimension 1D,
solvent’s default, no Z6, TUNE before and after off.
Topshim uses a complex algorithm needing a very good
starting point to converge. If the field homogeneity is really
poor the algorithm won’t find a valid result and an error
message such as «fieldmap - signal to noise is too low» or
«reduce echo time» may be displayed on the screen.
NB: to compensate for transverse field inhomogeneities spinning of the tube may be used
ONLY FOR 1D SPECTRA WITH BBO PROBE.
NB: scratched or dirty tube, poorly soluble sample, too concentrated sample, really
small or really large volume, paramagnetic impurities... may deteriorate the field
homogeneity. Shim tuning can’t compensate for everything, so be careful with your
sample!
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3.6 Gain
The NMR signal is weak and must be amplified by the receiver. The receiver gain - RG characterizes the signal amplification: a weak RG shows the sample is concentrated - the
signal doesn’t need to be strongly amplified.
RG ranges from 1 to 2050 - maximal value found for example for natural abundance carbon
observation. It is automatically calculated with > rga. It may be entered manually as well. To
read or change it enter > rg to display a dialog box with the actual window. Remember that
you may display any parameter in a dialog box.
Remember to run rga for 31P spectra. For 13C experiments rg is always maximal so no need
for rga. For protons 2D (COSY, TOCSY, NOESY, ROESY) you may copy the rg value
determined for the preceding 1H spectrum.
3.7 Some interesting acquisition parameters
To optimize your experiment you may change some acquisition parameters:
• the spectral window SW and its middle O1P
• the number of scans NS
• the relaxation delay D1
• the number of points TD
Most of these parameters may be found in the AcquPars window. Click on A to display all
the acquisition parameters, and click ∏ to return to the first default display.
If you don’t remember where to find a parameter, enter its name in the command line: for
O1P enter > o1p , a dialog box with the parameter to change will open.
Reminder: TD = 2 x AQ x SWH (where AQ: acquisition time and SWH: SW in Hz) and
TR (repetition time) = D1 + AQ
AQ must be long enough to record the full FID and TR must be long enough for
relaxation of the observe nucleus - for a quantitative spectrum. This means you
should increase D1 if you observe inconsistencies in the integration of your proton
spectrum.
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The number of scans - NS - and the relaxation delay - D1 - are decisive for the experiment
time: click on to check
the total time.
3.8 Some important commands
•
Acquisition
To start the acquisition after all the adjustements are done: > zg
Be careful zg = zero + go, this command erases any possible previous data before starting
the acquisition. If you wish to keep the previous data - e.g. 16 scans are already acquired
and you want to add some more because of a poor S/N - you may enter >go.
If you have prepared a set of experiments for the same sample (be careful as they must have
following EXPNOs), from the 1st one enter > multizg number_of_experiments.
Example:
1 - zg proton
2 - cosy
3 - hsqc
4 - zgpg carbone
from experiment 1 > multizg 4
•
Raw data transform
For 1D Fourier Transform
> ft .
Routinely > efp combines ft + exponential multiplication + phase according to the
parameters in ProcPArs (see § about process).
During acquisition you must transfer the firsts scans if you want to treat them: > tr then >efp.
With 2D
> xfb .
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4. SOME ROUTINE EXPERIMENTS
4.1 Which 13C 1D to choose?
•
«standard» spectrum: 1H decoupled carbon (zgpg)
•
spectrum with no decoupling (zg) to observe JCH couplings. Sensitivity may be an
issue and the increased number of peaks makes the spectrum more complicated to
assign.
•
udeft for molecules with quaternary carbons giving weak signals or even no signals
with the standard experiment
•
jmod: edited spectrum where Cq and CH2 signals are positive whereas CH and CH3
signals are positive.
•
dept135: edited spectrum like jmod but more sensitive thanks to a polarization
transfer from 1H to 13C. As a consequence no signals are observed for Cq.
dept135
jmod
decoupled
13
C
udeft, 4h total
decoupled
13
C, d1=20s, 10h total
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First acquire a decoupled spectrum before thinking about a non decoupled or a udeft. For
synthesis follow up that doesn’t need quaternary carbons observation run a dept or an HSQC
(2D even more sensitive than dept).
4.2 How to suppress a strong solvent signal?
In some cases - often with biological samples in solution in D2O
or even H2O/D2O - the solvent residual proton signal is really
intense compared to the signals from the sample.
The signal may be suppressed by applying a low power pulse at
the solvent resonance frequency (this is called presaturation)
during the relaxation delay d1.
First acquire a «standard» proton spectrum and note down the
frequency of the signal to suppress (in Hz, not ppm).
• create a new proton dataset and
change the PULPROG from zg30 to zgpr.
Don’t forget to run > getprosol to adjust
the presaturation power level.
• > o1 : in the pop up window enter
the resonance frequency of the signal to
suppress (in Hz). ATTENTION O1 is also
the middle of the spectrum! Check that
the spectral window is large enough , if it
is not change SW. If you’re not satisfied
with the signal suppression change O1 of a
few Hz.
4.3 How to calibrate a 13C, 31P or other X spectrum?
You need to acquire a proton spectrum right before your X spectrum and calibrate it
carefully.
Write down the precise value of SF (spectrum frequency) that you will find in the ProcPars of
the proton spectrum. Then multiply this value by the ratio - taken from the table below - for
the wanted nucleus (𝛯= 0.40480742 for referencing a 31P spectrum to H3PO4 for example).
The result is to be used as SF value for your X spectrum.
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Nucleus
Ref molecule
Frequency ratio 𝛯
13
C
0.25145020
TMS
19
F
0.94094011
CCl3F
29
Si
0.19867187
TMS
31
P
H3PO4
0.40480742
For other nuclei see ref Pure Appl. Chem., Vol. 73, No. 11, pp. 1795–1818, 2001.
4.4 «Standard» 2D experiments
Parameters sets fitted for observation of organic molecules are saved in the «MANIPS
MODELES» directory and may be read with > rpar SDQ* . The parameters to optimize and
the adjustements not to forget are summarized in the Title window.
Remember to acquire a proton spectrum before any 2D experiment to check shims, gain,
spectral window...
v
COSY : > rpar SDQ_COSY
COSY is a 2D experiment that shows correlations between
protons that share a scalar coupling (2JHH or 3JHH).
F2 column is for the direct dimension
(X axis), F1 is for the indirect
dimension (Y axis).
To prevent 2D experiments from being
time consuming the number of points
in the indirect dimension is significantly
lower than in the direct dimension.
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Try to change TD (F2 and F1), AQ and SW and see what happens. For each change
check the duration of the experiment.
F2
F1
comments
TD
1024 points
256 points
TD ok for a good resolution in F2
FIDRES (resolution)
4,9 Hz
19,5 Hz
SW
10 ppm
10 ppm
NUC
1
1
O1P/O2P
5 ppm
H
SW1 = SW2
H
5 ppm
O1P = O2P
HSQC : > rpar SDQ_HSQC
HSQC is a heteronuclear experiment that shows
1
JH-C scalar interactions.
The indirect dimension is now 13C so be
careful of spectral window. The default value
is 160 ppm centered at 80 ppm which is
enough for most organic compounds.
According to the observed molecule it might
be relevant to change these values (e.g. no
signals are expected in the aromatic region).
Reminder: no signals are observed for
quaternary carbons in HSQC!
F2
F1
comments
TD
1024 points
512 points
FIDRES (resolution)
4,9 Hz
39,3 Hz
Note that resolution in the C dimension is
almost 40 Hz, and even 80 Hz when TD1 is
256 points!
SW
SW1 = 10 ppm
SW2 = 160 ppm
NUC
1
13
O1P/O2P
O1P = 5 ppm
H
13
C
O2P = 80 ppm
4.5 Some other 2D
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HMBC > rpar SDQ_HMBC
HMBC shows 2JH-C and 3JH-C (even 4JH-C) scalar
heteronuclear correlations.
The value for the observed long distance coupling may be changed - it is the CNST13
parameter. Furthermore CNST2 is the value of the residual 1JC-H couplings that are filtered
from the spectrum.
HMBC is a low sensitivity experiment so remember to use twice the number of scans needed
for HSQC. It is really helpful with HMBC interpretation to superimpose the two spectra
(HSQC + HMBC). Be careful as 3JCH USUALLY lead to MORE intense signals than 2JCH.
However the intensities happen to be similar in some cases.
v
NOESY / ROESY
NOESY and ROESY experiments rely on
the existence of a dipolar intercation
between 2 nuclei at close distance (<5Å)
that leads to an effect called NOE. NOE
depends on the distance between the nuclei
as well as on correlation time of the
molecule 𝜏c. The sign of the NOE depends
on 𝜏c .
For middle size molecules (600 < MW<1500
g.mol-1 depending on solvent viscosity)
NOESY might be inconclusive and it is
advised to acquire also a ROESY.
NOESY and ROESY spectra show signals due to a NOE and exchange signals. The signs of
both kinds of cross peaks are detailed in the following table for a spectrum with a negative
diagonal:
ω 0τ c < 1
ω 0τ c ≈ 1
ω0τc >1
NOESY cross peak
+
0
-
ROESY cross peak
+
+
+
exchange signals
-
-
-
v NB: other experiments are available on this spectrometer. 2D HSQC_10ppm and
HMBC_10ppm for example give spectra with a 3Hz resolution in the carbon dimension
(instead of 40Hz at best with a standard HSCQ).
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5. TOPSPIN 2.1
Tabs to browse the different windows
associated with an experiment
Command line
Topspin’s toolbar include different menus - the more interesting for you being Processing and
Analysis - and clickable buttons.
o
edit
o
vertical scale (signals intensity)
o
horizontal scale (zoom)
o
spectrum navigation
o
data manual processing
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• Superimposition of 1D or 2D spectra
Click on
then select the 2nd spectrum in the browser and drag it over the 1st one.
To make adjustments on a single of these spectra (intensity...) select it in the menu down on
the left then use the buttons from the menu in the superimposition window
• Windows layout
You can work with several spectra displayed on the computer screen with a correlated
cursor. You can choose to have your spectra vertically or horizontally displayed, or even as a
grid. Try the different option from the Window menu
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6. PROCESSING OF 1D DATA
Basic treatment after fourier transform consists in phase correction and baseline correction.
> apk and > abs n perform automatic phase and baseline corrections that are often
satisfying.
6.1 Some interesting processing parameters
Look in the ProcPars window.
SI = TD or 2*TD to have enough points for well
defined signals
SR is the offset in Hz due to manual calibration of the
spectrum (see §6.4).
The default «window function» is an exponential (EM)
with a Line Broadening factor (LB) of 0.3 Hz.
The multiplication of FID with an exponential function increases S/B ratio but it also
broadens the signals - which might result in a loss of coupling information. The optimal LB
value is measured at half height of the peaks in a spectrum obtained with «ft». With ef LB is
always POSITIVE.
These parameters are taken into account when applying the fourier transform > ef (= ft + em)
or > efp (to use also the phase correction parameters PH0 and PH1).
ef, LB=2
ef, LB=1
ef, LB=0,3
ft
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Multiplication of FID with a gaussian function may also
be helpful. WDW, LB and GB have to be modified in
ProcPars. WDW = GM, then LB and GB are adjusted
according to the expected result. The example below
illustrates the impact of LB and GB on the separation of
overlapping peaks.
With gf, LB is always NEGATIVE and 0 < GB < 1. Be
careful as high values of GB and LB may lead to the
loss of weak signals.
n ft
n ft
n ef, LB=0,3
n gf, GB=0,1, LB=-0,3
n ef, LB=1
n gf, GB=0,1, LB=-1
n gf, GB=0,1, LB=-2
n ft
n ft
n gf, GB=1, LB=-0,3
n gf, GB=0,5, LB=-0,3
n gf, GB=1, LB=-1
n gf, GB=0,5, LB=-1
n gf, GB=1, LB=-2
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6.2 Phase correction
If you’re not satisfied with the phase
correction obtained with >apk you may
correct it manually. Click on
to display
the phase correction window. LEFTCLICK-HOLD on 0 and roll the mouse
up or down for phase correction of the
region near the red pivot point. Then
click on 1 and adjust the phase in the
regions far from the pivot point. Don’t
forget to save before you quit.
6.3 Baseline correction
If you’re not satisfied with the baseline correction obtained with > abs n you may correct it
manually. Click on
to display the baseline correction window. Zoom out to see all the
spectrum in the window. LEFT-CLICK-HOLD on A and roll the mouse up or down to distort
the baseline. Do the same with B, C, D and E.
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6.4 Spectrum calibration
Topspin calibrates the chemical shifts
using the solvent signal as a reference.
This calibration may be unsatisfying - e.g.
D2O chemical shift
depends on
temperature and pH. You may calibrate
the spectrum manually. Expand the
region
of
the
reference
signal
(chloroform...) Click on
to display the
calibration window. Then click on the
signal and enter the right frequency in
ppm in the dialog box.
The shift applied to the initial spectrum is
stored in the process parameter SR (in
Hertz).
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7. PROCESSING OF 2D DATA
Once your data have been processed with > xfb remember to correct the baseline in the
indirect dimension > abs1 only if your experiment needs a manual phase correction (HSQC,
NOESY, ROESY).
NB: COSY and HMBC routine experiments on this spectrometer are not phase sensitive and
thus are processed in magnitude mode: all signals are positive.
7.1 Contour levels
For a better resolution of 2D spectra the number of contour
levels may be increased.
o
right-click on the spectrum
o
select « Edit contour levels »
o
replace 1.8 by 1.3 and 8 by 20
o
click, in that order, on Fill, Apply and OK
7.2 Phase correction
For phase correction in the direct
dimension click on
to display the
phase correction window. Right-click and
« Add » on 2 distant signals.
Then click on
(row) and phase the
extracted rows as they should be (here
CH2 signals are supposed to be
negative).
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7.3 1D projections
You may replace the 1D projections with previously acquiried 1D spectra. Right click on the
projection and select “External projection”. Write the experiment number of the spectrum to
be displayed.
Copy the SR value from the 1D spectrum used as
external projection and paste it in the corresponding SR
(F2 or F1) in the ProcPars. If the 2D spectrum still looks
a bit off you may calibrate it manually: click
and do
as for a 1D spectrum.
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8. TROUBLESHOOTING
Bruker hotline number: 03-88-06-60-00. Tell you are a working in the ENS Chemistry
lab in Lyon and explain your problem. Give the reference of the 500MHz spectrometer
if asked (SH003706).
û
HOW TO REBOOT THE SAMPLE CHANGER?
First switch it off (press a few seconds the blue button in front). Then gently remove the
carousel. Switch on the blue button WITHOUT the carousel. Wait for the upper light to go
from orange to blue. Put the carousel back into place, gently! The carousel should turn
around and the light should go from blue to white then green.
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HOW TO CHANGE A DATASET LOCATION
If you start from an experiment in MANIPS MODELES remember to change the USER!!!!! If
you forget and your dataset is saved in the wrong directory use the linux files explorer to
move it in the right folder.
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TOPSHIM COMMON ERROR MESSAGES
If you encounter an error message such as “Echo time must reduced” or “FieldMap signal-to-noise is too low” this means that the shims you are trying to optimize are not
good enough for the optimization algorythm.
--> You can load another set of shims (>rsh and choose a recent file for the right probe, the
solvent is not important) and start Topshim again. You can also tune before on Z-X-Y or even
Z-X-Y-XZ-YZ-Z to optimize the transverse shims before starting the optimization procedure.
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OTHER SHIM ISSUES
>rsh if for shims reading and >wsh is for shims writing. You may write shims for a specific
solvent or sample if you need it. Don’t overwrite the existing shims files.
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TUNING ISSUES
If you need to tune the probe manually you may use the command >atmm instead of >atma.
It opens the wobb and a window with <<< << < > >> >>> buttons for matching and tuning of
your nucleus.
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user manual
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If you can’t see the minimum of the tuning curve on the screen try a wider wobb window.
Click
and change the width from 4 to 20 MHz.
To change nucleus when using the TXI (if you’re tuning a crabon spectrum for example) click
.
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HOW TO STOP A PROCESS (MULTIZG FOR EXAMPLE)
>kill is used to stop a multizg. It opens a window showing the running processes. Select the
“multizg” line and click Kill. You may need to repeat this once or twice.
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HOW TO RUN AN EXPERIMENT ON AN “EXOTIC” NUCLEUS
The POWERCHECK prevents the use of intense pulses that may damage the probe. For
some nuclei you might encounter an error message (quite long). Click OK to switch off the
POWERCHECK during your experiment. Then enter spin1/2 as the NMR password.
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CF: CONFIGURATION PROCEDURE
>cf allows you to configure the spectrometer. It is useful when:
o
you want to switch of the POWERCHECK when running multiple experiments
on exotic nuclei
o
you need to restart the spectrometer after a power cut
o
something is changed in the hardware (a connection is changed, an amplifier
is disconnected...)
o
you have a problem and the guy from Bruker hotline tells you to do so
The password required for cf is spin1/2. A complete description of the cf procedure will be
discussed during training session. If you have any problem when running a cf, or even the
slightest doubt about a parameter, call Bruker hotline and ask for advice.
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HOW TO SWITCH OFF/ON THE SPECTROMETER
•
OFF the heater (in EDTE)
•
quit Topspin
•
OFF BCU (next to the magnet)
•
OFF amplifiers
•
OFF BVT
•
OFF BSMS
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•
OFF l’AQS
•
OFF computer and screen
•
OFF the main button LAST
o
ON the main button FIRST
o
ON computer and screen
o
ON AQS
o
ON BSMS
o
ON BVT
o
ON amplifiers
o
ON BCU
o
start Topspin
o
cf until there is no more error messages
o
rsh to load shims
user manual
2015
If you have any problem when rebooting the spectrometer, or even a question, call
Bruker hotline and ask for advice.
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9. INDEX
BSMS, 3
POWERCHECK, 25
calibrate, 12
presaturation, 12
carbon, 11
probe, 2, 7
carousel, 24
spectral wndow, 9
exponential function, 18
spinning, 8
gaussian function, 19
SR, 21, 23
integration, 9
time, 10
multizg, 10, 25
Topshim, 8, 24
NOE, 15
Tuning, 7
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