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

Abstract

We have applied a combination of H quantitative NMR spectroscopy (H-qNMR) and chromatography (GC or LC) to establish reliable analytical methods (qNMR/GC and qNMR/LC) for organic compounds. In this method, a reference standard is used as an internal standard for both H-qNMR and chromatography to estimate relative molar sensitivity (RMS) for analytes. The RMS values are calculated from the molar ratios between analytes and the reference standard obtained byH-qNMR; and the response ratio between them obtained by chromatography. Concentrations of analytes in the organic solution can be simultaneously determined from the RMS and amount of the reference standard added in the sample solution. This analytical method is an innovative one because only one reference standard with International System of Units (SI)-traceable property value, purity, or concentration, is necessary to determine accurate concentrations of multiple organic components in organic solutions, without the respective certified reference standards for various analytes. To verify this method, a certified reference material, NIST SRM 1647f, was used. Among the 16 polycyclic aromatic hydrocarbons (PAHs) included in NIST SRM 1647f, naphthalene and benzo[a]pyrene were selected as analytes for this method, using 1,4-bis(trimethylsilyl)benzene-d as the reference standard. Each quantitative value obtained by qNMR/GC and qNMR/LC agreed with each certified value within its expanded uncertainty.

Analysis of Polycyclic Aromatic Hydrocarbon (PAH) Mixtures Using Diffusion-Ordered NMR Spectroscopy and Adsorption by Powdered Activated Carbon and Biochar

“…Recently, NMR spectroscopy has shown great potential in environmental research, since it is able to study liquids, gels, solids, gases, and multiphase samples and produce rapid, reliable, and highly sensitive results [ 10 , 11 , 12 ]. Quantitative NMR spectroscopy can also provide accurate quantitative information about the sample constituents [ 13 ]. Unlike GC, NMR spectroscopy does not require multiple detectors, and it is capable of analyzing mixtures with advanced spectroscopic methods, such as multi-dimensional spectroscopy and diffusion-ordered NMR spectroscopy [ 10 , 14 , 15 , 16 ].…”

Narrative review of metabolomics in cardiovascular disease

“…This is especially crucial in studies using mice, where only small amounts of tissue or biofluids are available or for studies with human tissue material of low availability. In the last years, most metabolomic studies used NMR as a stand-alone technique, however a complimentary approach with MS is becoming increasingly popular, as it improves sensitivity and metabolome coverage (26)(27)(28).…”

Miroestrol Quantification in <i>Pueraria mirifica</i> Crude Drugs and Products by Single-Reference UPLC/PDA/MS Using Relative Molar Sensitivities to Kwakhurin

“…Several studies have reported conventional quantification methods for MIR and its derivatives in PM plants using HPLC 4,10) and in PM dietary supplements using liquid chromatography/tandem mass spetrometry (LC/MS/MS). 11) However, detection of MIR in PM may be difficult owing to its low content and the multiple interfering compounds in crude drugs or other ingredients in products. Additionally, not only analytical standards but also commercial reagent-grade MIR is hardly available for routine analysis.…”