The University of Chicago

NMR Facility - Chemistry Department

Training - Level1

Everyone seeking access to the facility’s NMR instruments starts with Level1 training, which enables access to our autosampler-equipped spectrometer. Leveraging our automation for data collection, we focus on magnet lab safety, proper sample preparation, detailed data processing techniques, and facility policies. Interaction with the spectrometer only takes about ten minutes, and emphasizes the different experiments and available and which are best for users’ purposes.

For the occasional NMR user, we’ve found this provides enough expertise and access to acquire meaningful data without delving into the details of spectrometer operation or NMR theory.

Topics Covered

Orientation, Safety, and Sample Prep
(~90 min)

Orientation

  • Orientation to the two NMR laboratories and Searle’s chemistry support lab
  • Introduction to the different spectrometers and their main uses

Safety

  • Identification of exits, fire extinguishers, first aid kits, cleaning supplies
  • Check for pacemakers and insulin pumps
  • Working around high-field magnets
  • Cryogens in the lab
  • Using a secondary container for bringing sample to/from lab
  • Sample handling; what do do if samples break outside and inside the equipment
  • Various cautions based on prior events

Sample Preparation

  • Sample preparation requirements and best practices
    • why samples must be > 0.5 mL
    • why particulates give rise to bad spectra
    • proper use of the sample depth gauge
  • NMR tube selection and care
  • NMR tube length requirements
  • Proper positioning of samples in spinners

Policy

  • Permissions for handling other people’s samples
  • The “two-rack” system for managing completed samples

Submitting samples
(~20-30 min)

  • Orientation to the ICON-NMR interface in Bruker’s Topspin software
  • How to find an available carousel position
  • Mechanics of adding an experiment to the acquisition queue; how to add additional experiments to one sample
  • Review of available experiments and what information they provide
  • Discussion of how the number of scans affect the signal-to-noise ratio (S/N)
  • How to edit acquisition parameters

Processing data and Certification Quiz
(~90 min)

  • Orientation to the Bruker Topspin 3 layout (“flow mode”)
  • Locating and opening data files

1D ¹H Data

  • Cursory examination of an example spectrum
  • Orientation to the different tabs in the spectrum
  • Time-domain vs frequency-domain data
  • The Fourier transform
  • “Phasing” and why we do it
  • Zero-filling and digital resolution
  • Window functions, line broadening, and effects on S/N
  • Evaluation of spectrum quality – linewidth measurement
  • Baseline correction
  • Frequency referencing
  • Peak picking
  • Integration

1D ¹³C Data

  • Examination of normal 1D ¹³C spectrum
  • Examination of ¹³C DEPT-135 spectrum

2D NMR Spectra

  • Orientation to the 2D COSY experiment and how to use it
  • Orientation to the 2D ¹H-¹³C HSQC experiment and how to use it
  • Orientation to the 2D ¹H-¹³C HMBC experiment and how to use it

Data transfer procedures

  • How to get data collected on an instrument to one’s laptop

Certification Quiz

  • A 20-minute quiz covering material discussed in the training session
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