Calibration specification for superconducting pulsed Fourier transform nuclear magnetic resonance spectrometers
1 Scope
This specification is applicable to the calibration of superconducting pulsed Fourier transform nuclear magnetic resonance spectrometers (hereinafter referred to as the spectrometers) at 300MHz and above.
2 Normative references
ASTM E386-90 (2011) Standard practice for data presentation relating to high-resolution nuclear magnetic resonance (NMR) spectroscopy
Handbook of analytical chemistry - Volume 7: Spectral analysis of nuclear magnetic resonance Beijing: Chemical Industry Press
For dated references, only the dated edition applies. For undated references, the latest edition of the normative document (including any amendments) applies.
3 Terms and meteorological units
3.1 Chemical shift
resonance of protons or other magnetic nuclei in the same magnetic field at different frequencies due to different chemical environments in molecules; the scale of which is usually expressed by the resonance frequency difference between the measured reference material and the sample under test, recorded as δ of dimension one
(1)
Where,
vS——the resonant frequency of the sample, Hz;
vR——the resonant frequency of reference material, Hz;
vspectrometer——the working frequency of the spectrometer, Hz.
3.2 Free induction decay (FID)
induction signal appears in the receiver coil of spin system under the action of pulse, the intensity of which decays with time
3.3 Line broadening factor
factor used for exponentially weighting each data point of free induction decay signal, and weighting is not performed when the factor is equal to zero
4 General
4.1 Principle
Introduction ii
1 Scope
2 Normative references
3 Terms and meteorological units
3.1 Chemical shift
3.2 Free induction decay (FID)
3.3 Line broadening factor
4 General
4.1 Principle
4.2 Spectrometer composition
5 Metrological characteristics
6 Calibration conditions
6.1 Laboratory environment
6.2 Reference materials
6.3 Laboratory conditions
7 Calibration items and methods
7.1 1H spectral sensitivity
7.2 13C spectral sensitivity
7.3 1H spectral resolution
7.4 13C spectral resolution
7.5 1H spectral line shape
7.6 13C spectral line shape
7.7 1H spectral quantitative repeatability
8 Calibration result
9 Recalibration time interval
Annex A Format of calibration record
Annex B Inside page format of calibration certificate
Annex C Suggested parameters of spectrometer
Annex D Evaluation of uncertainty
