### Abstract

Language | English |
---|---|

Pages | 4286-4294 |

Number of pages | 8 |

Journal | Analytical Chemistry |

Volume | 73 |

Issue number | 17 |

DOIs | |

Publication status | Published - 2001 |

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### Keywords

- free induction decay
- generalized rank annihilation method
- fid
- gram
- direct exponential curve resolution algorithm
- decra
- NMR
- Hankel matrix

### Cite this

*Analytical Chemistry*,

*73*(17), 4286-4294. https://doi.org/10.1021/ac0102866

}

*Analytical Chemistry*, vol. 73, no. 17, pp. 4286-4294. https://doi.org/10.1021/ac0102866

**Quantitative analysis of low-field NMR signals in the time domain.** / Nordon, A.; Gemperline, P.J.; McGill, C.A.; Littlejohn, D.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Quantitative analysis of low-field NMR signals in the time domain

AU - Nordon, A.

AU - Gemperline, P.J.

AU - McGill, C.A.

AU - Littlejohn, D.

PY - 2001

Y1 - 2001

N2 - Two novel methods are described for direct quantitative analysis of NMR free induction decay (FID) signals. The methods use adaptations of the generalized rank annihilation method (GRAM) and the direct exponential curve resolution algorithm (DECRA). With FID-GRAM, the Hankel matrix of the sample signal is compared with that of a reference mixture to obtain quantitative data about the components. With FID-DECRA, a single-sample FID matrix is split into two matrices, allowing quantitative recovery of decay constants and the individual signals in the FID. Inaccurate results were obtained with FID-GRAM when there were differences between the frequency or transverse relaxation time of signals for the reference and test samples. This problem does not arise with FID-DECRA, because comparison with a reference signal is unnecessary. Application of FID-DECRA to 19F NMR data, which contained overlapping signals from three components, gave concentrations comparable to those derived from partial least squares (PLS) analysis of the Fourier transformed spectra. However, the main advantage of FID-DECRA was that accurate (<5% error) and precise (2.3% RSD) results were obtained using only one calibration sample, whereas with PLS, a training set of 10 standard mixtures was used to give comparable accuracy and precision.

AB - Two novel methods are described for direct quantitative analysis of NMR free induction decay (FID) signals. The methods use adaptations of the generalized rank annihilation method (GRAM) and the direct exponential curve resolution algorithm (DECRA). With FID-GRAM, the Hankel matrix of the sample signal is compared with that of a reference mixture to obtain quantitative data about the components. With FID-DECRA, a single-sample FID matrix is split into two matrices, allowing quantitative recovery of decay constants and the individual signals in the FID. Inaccurate results were obtained with FID-GRAM when there were differences between the frequency or transverse relaxation time of signals for the reference and test samples. This problem does not arise with FID-DECRA, because comparison with a reference signal is unnecessary. Application of FID-DECRA to 19F NMR data, which contained overlapping signals from three components, gave concentrations comparable to those derived from partial least squares (PLS) analysis of the Fourier transformed spectra. However, the main advantage of FID-DECRA was that accurate (<5% error) and precise (2.3% RSD) results were obtained using only one calibration sample, whereas with PLS, a training set of 10 standard mixtures was used to give comparable accuracy and precision.

KW - free induction decay

KW - generalized rank annihilation method

KW - fid

KW - gram

KW - direct exponential curve resolution algorithm

KW - decra

KW - NMR

KW - Hankel matrix

UR - http://dx.doi.org/10.1021/ac0102866

U2 - 10.1021/ac0102866

DO - 10.1021/ac0102866

M3 - Article

VL - 73

SP - 4286

EP - 4294

JO - Analytical Chemistry

T2 - Analytical Chemistry

JF - Analytical Chemistry

SN - 0003-2700

IS - 17

ER -