Development of a Novel Method for Quantifying Quassin and Neoquassin in Jamaica Quassia Extracts Using the Molar Absorption Coefficient Ratio

Abstract

A novel HPLC-based method employing molar absorption coefficient ratios to 4-hydroxybenzoic acid 4HBA was developed for the determination of quassin and neoquassin in Jamaica quassia extract, which is used as a food additive in Japan. Based on comparisons of quantitative NMR qNMR spectra and HPLC chromatograms of an artificial mixture of quassin, neoquassin, and 4HBA, the molar absorption coefficient ratios of quassin and neoquassin to 4HBA were determined as 0.84 and 0.85, respectively. Quassin and neoquassin were quantified in food additives by qNMR and HPLC based on molar absorption coefficient ratios using 1,4-bis trimethylsilyl benzene-d 4 and 4HBA as internal standards, respectively. The differences in quantitation values between qNMR and HPLC analyses were below 1.2 . Our proposed novel HPLC-based quantitation method employing the molar absorption coefficient ratios is a reliable tool for determining levels of quassin and neoquassin in food additives and processed foods.

Determination of PAHs in Solution with a Single Reference Standard by a Combination of 1H Quantitative NMR Spectroscopy and Chromatography

“…On the other hand, offline NMR was also applied to determine organic compounds separated by LC without their own reference standards. , We have applied this method for natural product analyses, quantification of quassin and neoquassin in Jamaica Quassia extracts . For this method, a reference standard is used as an internal standard for both 1 H-qNMR and chromatography to estimate the relative molar sensitivity ( RMS ) for each analyte.…”

Determination of Mogroside V in Luohanguo Extract for Daily Quality Control Operation Using Relative Molar Sensitivity to Single-Reference Caffeine

“…To establish accurate calibration curves, purity of the mogroside V standard was determined by 1 H-qNMR using internal standard. 5,6) The 1 H-qNMR spectrum of solution NMR 1 is shown in Fig. 3.…”

“…Because the detection sensitivity of 1 H-qNMR is proportional only to the number of 1 H nuclei, analyte purity can be accurately estimated by comparing the signal areas of the analyte with those of a CRM that is prepared for 1 H-qNMR and used as an internal standard. 5,6) Since exact purities of reagents at any grade can be calculated by 1 H-qNMR, the accurate calibration curves of analytes can be constructed with HPLC/VWD. From the ratio of slopes of these accurate calibration curves of an analyte and a single-reference, an accurate RMS can be obtained.…”

Development of an HPLC method with relative molar sensitivity based on 1H-qNMR to determine acteoside and pedaliin in dried sesame leaf powders and processed foods

“…Therefore, the analyte's absolute quantitative value can be determined with metrological traceability to the International System of Units (SI) if a specific CRM is used as the IS in 1 H-qNMR [3,4]. A HPLC method using the relative molar sensitivity (RMS) of 1 H-qNMR (RMS method) was recently reported to quantify analytes using a reference standard different from the analyte [5]. RMS is calculated by the ratio of the molar absorption coefficient of the analyte to that of this alternative reference standard by correcting the analytes' purities using 1 H-qNMR.…”