1. EZ NMR to Simplify NMR

  • routine 1D and 2D NMR techniques accessible to students/PDFs that may have minimal experience with NMR and a minimum desire to learn (minimum does not mean zero!)
  • from acquisition to processing, plotting and saving of data without commands for 7 common solvents and 13 less common ones
  • buttons/icons instead of commands (ca. 400 macros, parameter sets and menus implemented)
  • VNMRJ commands and macros and the ability for users to write and use their own macros, parameter sets etc. is retained
  • 8 NMR spectrometers: 300, 3x400 (1 with an autosampler), 2x500, 600 and 700 MHz spectrometers with identical operation (VNMRJ and EZ NMR)
  • central data storage (data available on all NMR-related computers) and central data storage for undergraduate NMR (data available in W1-50 computer lab)
  • quota system for data storage: no overuse of disk space by other user(s)
  • 4.7 Gbyte DVD-Writer, 700 MByte CD-Writer, and USB key support on data stations for data archiving, backup, and transport
  • extensive use of local network to make centrally stored data available on work stations throughout the Department (Linux, Mac OS-X and Windows)
  • booking of spectrometer time via HTML interface

Documentation for usage of the m400 can also be found at: http://nmr.chem.ualberta.ca.

2. Introduction

This document deals exclusively with high-resolution (i.e. liquid not solid state) Linux-based Agilent NMR spectrometers which are all linked through the local Ethernet network.

The main objective of this manuscript is to provide information on how to run these spectrometers in a safe and efficient way by using specific locally developed menu panels  referred to as “EZ NMR”. With the help of these panels, 1D and 2D data can be acquired, processed and plotted without explicitly entering commands. The explanation of general VNMRJ commands is kept to a minimum as there are excellent manuals located on each spectrometer and data station (on-line pdf manuals). Spectrometer host computers and data stations are equipped with the following manuals:

  • VNMRJ Command and Parameter Reference (very useful)
  • NMR spectroscopy, User Guide (useful to learn about the system in general)
  • VNMR User Programming (useful only if you want to write your own macros and pulse sequences)

which are instructive for those wishing to learn more about general VNMRJ commands.

Except for the field strength, associated spectral dispersion and sensitivity, the operation of all instruments and data stations is essentially identical as they are all equipped with similar hardware, use the same version of the Linux operating system and use similar versions of VNMRJ software:

  • Linux: Red Hat Enterprise Linux 5 (RHEL 5)
  • VNMRJ: 2.2D (Mercury) or 3.2A (Inova, VNMRS, and Data Stations)

2.1 The NMR Staff and Spectrometers

The Department of Chemistry has 8 high-resolution NMR spectrometers and a small staff of three personnel dedicated to the care and maintenance of these instruments as well as aiding users with anything liquid NMR related. The NMR staff are also available to measure samples for users that require special techniques, long experimental times (dilute samples), require immediate attention (unstable compounds), training new users, plus many other items.

2.1.1 The NMR Staff

The NMR staff can be found in on the third floor of the East wing, room E3-17A and room WB-13 in the basement of the West wing within the Department of Chemistry.

3rd Floor East Wing:
The NMR Laboratory Supervisor, Dr. Ryan McKay (email: ryan.mckay@ualberta.ca), room E3-17A (phone: (780) 492-9950).

Basement West Wing:
The NMR service staff Mark Miskolzie (email: mark.miskolzie@ualberta.ca) and Nupur Dabral (email: nupur.dabral@ualberta.ca), and one 400 MHz Inova, referred to as s400: basement West wing, room WB-13 (phone: (780) 492-2573).

For concerns with the instruments or data stations please notify the NMR staff immediately in person, by phone, and/or by email.

2.1.2 The Spectrometers

The rest of the NMR instruments are located throughout the Department and can be found:

Sub-Basement:

  • one 400 MHz MR, referred to as mr400: sub-basement East wing, room 3E (492-8619)
  • one 400 MHz Inova, referred to as i400: sub-basement East wing, room 3E (492-8619)
  • one 600 MHz VNMRS, referred to as i600: sub-basement East wing, room 3F (492-8588)

Basement:

  • one 500 MHz Inova, referred to as ibd5: basement East wing, room EB-44 (492-3507)
  • one 500 MHz VNMRS (auto sampler), referred to as u500: basement East wing, room EB-44 (492-3507)
  • one 700 MHz VNMRS (auto sampler), referred to as v700: basement East wing, room EB-44 (492-2801)

First Floor:

  • one 400 MHz Mercury+ (auto sampler), referred to as m400: main floor West wing, room W1-19 (492-4472)

2.2 Data Stations and Remote Access PointsAAll general access data stations and remote access points behave the same as the spectrometers.

Data stations support: archiving data to CD, DVD, USB devices, and remote login via ssh within the Department of Chemistry. Please see the Facility Supervisor for permission to access a data station remotely.

Remote access points DO NOT support: archiving data to CD, DVD, USB devices, or remote login via ssh. These systems are for processing and printing data ONLY.

Seven general access data stations are available for data processing and archiving data:

  • W1-19: d401; EB-44: ibdw and d300; WB-13: d500; SB-3G: d601and d602; CCIS 4-280: d501

One remote access point is available for data processing and printing data only:

  • CCIS 4-280: d501 Remote

3. NMR System Overview

Each spectrometer consists of three main components:

nmr components

Figure 3.1: The main components of an NMR spectrometer

Aside from inserting and removing your sample the entire system is controlled nearly 100% from the spectrometer host computer.

3.1 Consoles, probes and other hardware

Spectrometer

mr400

m400
(autosampler)

i400

ibd5

u500
(autosampler)

i600

v700
(autosampler)

Console

DD2 MR

Mercury

Inova

Inova

VNMRS

VNMRS

VNMRS

Magnet Bore Size

54mm

54mm

54mm

51mm

51mm

51mm

54mm

No. Channels

2

2

2

4

2

4

4

Probe

onenmr

4 nuc

autoxdb

autoxdb

dual cold probe

autoxid HCN probe

HCN cold probe

Tuning

Protune

No Tuning

Protune

Protune

Protune

Protune

Protune

Pulsed Field Gradient

Y

Y

Y

Y

Y

Y

Y

H1 S/N

510:1

190:1

280:1

350:1

2200:1

1200:1

7000:1

C13 S/N

175:1

155:1

180:1

250:1

1500:1

165:1

900:1

F19 S/N

690:1

300:1

375:1

345:1

N

N

N

P31 S/N

180:1

76:1

190:1

155:1

N

N

N

Li7, B11, Si29, Sn119, Plus Other Heteronuclei

Y

N

Y

Y

N

N

N

2D

Y

Y

Y

Y

Y

Y

Y

3D

N

N

N

Y

N

Y

Y

Temp. Control

Y

Y

Y

Y

Y

Y

Y

3.2 Sensitivity and spectral dispersion

H1 sensitivity and resulting experimental times or sample concentration, respectively, to reach the same signal-to-noise is compared below:

 

mr400

m400

i400

ibd5

u500

i600

v700

H1 sensitivity

510:1

190:1

280:1

350:1

2200:1

1200:1

7000:1

expt. time to reach H1 s/n at a given sample concentration [min]

8.4

60

28

18

0.44

1.5

0.04

sample concentration required to reach H1 s/n in a given time [mM]

5.6

40

18.4

11.8

0.3

1

0.03

sweep width for 10 ppm H1 [Hz]

4000

4000

4000

5000

5000

6000

7000

Spectral dispersion is proportional to the field strength hence a 600 is twice as good as a 300. The probability for spectral overlap in a two-dimensional experiment decreases significantly with increasing field strength:

300:  1.0        400:  0.56           500:  0.36           600:  0.25         700:  0.18

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