NMR quantification using an artificial signal

Abstract

We have developed QUANTAS (QUANTification by Artificial Signal), which is a software-based protocol for concentration measurement by NMR. QUANTAS is an absolute intensity external standard method for quantification by NMR that compensates for various experimental parameters. It is applicable to all nuclei and modern spectrometers. QUANTAS is demonstrated here for (1)H and (19)F NMR, enabling heteronuclear integrals to be compared. It can be applied using fixed probe tuning, matching and pulse length, for samples with the same effective loading on the probe coil as the appropriate reference spectrum. Otherwise, an optimised tuning and matching approach is adopted for every sample together with explicit PULCON (PUlse Length-based CONcentration measurements) absolute intensity corrections.

Determination of the purity of pharmaceutical reference materials by 1 H NMR using the standardless PULCON methodology

“…However, the literature on application of the PULCON method is rather scarce [5][6][7]20,21]. The objective of the present investigation was to apply a PULCON NMR method for precise measurements of purity of pharmaceutical reference standards and to compare this methodology with NMR quantification with internal standard and reference methods.…”

“…The quantification is performed using the PULCON (PULse length based CONcentration determination) methodology (different from ERETIC1), which is based on the principle of reciprocity, meaning that the NMR signal intensity for a sample compound in a given coil is inversely proportional to 90 • or 360 • pulse length [6,20]. PULCON compensates signal intensities for losses in coil sensitivity due to sample-to-sample changes in dielectric properties (ionic strength) and does not require specialized equipment to be performed [19].…”

Isolation and quantification of pinitol in Argyrolobium roseum plant, by 1H-NMR

“…Proton Magnetic Resonance (PNMR) spectroscopy is becoming of great importance [9][10][11][12][13][14][15][16] in the determination and quantitative analysis of natural products, food products and drug metabolites. The plant extract is a biogenetic cocktail and some of the components in this biogenetic cocktail show poor response to commonly used Diode Array, UV/VIS and Fluorescent detectors.…”

Software-assisted serum metabolite quantification using NMR

“…3.0, Bruker BioSpin, Rheinstetten, Germany), and quantification by artificial signal (QUANTAS) [27]. These methods show degrees of accuracy and robustness of quantification similar to those of the other reference methods.…”

“…ERETIC2 quantification is highly accurate [27,33,34] and, although Chenomx has been widely used for absolute quantification, this method has not been well tested with respect to the accuracy of quantification. To the best of our knowledge, in 2006 only one publication described Chenomx quantification [35], and noted the discrepancy in line fitting between peaks, all of which belong to the same metabolite.…”