Parahydrogen hyperpolarization of minimally altered urine samples for sensitivity enhanced NMR metabolomics

2021 ◽  
Author(s):  
Kerti Ausmees ◽  
Nele Reimets ◽  
Indrek Reile
Keyword(s):  
Solid Phase Extraction ◽  
Urine Analysis ◽  
Solid Phase ◽  
Urine Samples ◽  
Phase Extraction ◽  
Nmr Metabolomics ◽  
Nmr Sensitivity

Parahydrogen hyperpolarization has been shown to enhance NMR sensitivity in urine analysis by several orders of magnitude if urine samples are prepared by solid phase extraction (SPE). We present a...

scholarly journals A high-throughput and sensitive methodology for the quantification of urinary 8-hydroxy-2′-deoxyguanosine: measurement with gas chromatography-mass spectrometry after single solid-phase extraction

2004 ◽  
Vol 380 (2) ◽  
pp. 541-548 ◽  
Author(s):  
Hai-Shu LIN ◽  
Andrew M. JENNER ◽  
Choon Nam ONG ◽  
Shan Hong HUANG ◽  
Matthew WHITEMAN ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Solid Phase Extraction ◽  
Healthy Subjects ◽  
Solid Phase ◽  
Large Population ◽  
Urine Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Phase Extraction ◽  
Freeze Dried ◽  
Wide Range

8-Hydroxy-2´-deoxyguanosine (8OHdG) is a widely used biomarker for the measurement of endogenous oxidative DNA damage. A sensitive method for the quantification of 8OHdG in urine by single solid-phase extraction and GC-MS (gas chromatography with MS detection) using selective ion monitoring is described in the present study. After solid-phase extraction, samples are freeze-dried, derivatized by trimethylsilylation and analysed by GC-MS. The urinary 8OHdG was quantified using heavy isotope dilution with [18O]8OHdG. The recovery of 8OHdG after the solid-phase extraction ranged from 70 to 80% for a wide range of urinary 8OHdG levels. Using 1 ml of urine, the limit of quantification was >2.5 nM (2.5 pmol/ml) and the calibration curve was linear in the range 2.5–200 nM. This method was applied to measure 8OHdG in urine samples from 12 healthy subjects. The intra- and inter-day variations were <9%. Urinary 8OHdG levels in spot urine samples from four healthy subjects were also measured for 1 week and, again, the variation was small. The presence of H2O2 in urine did not cause artifactual formation of 8OHdG. Since this assay is simple, rapid, sensitive and reproducible, it seems suitable to be used as a routine methodology for the measurement of urinary excretion of 8OHdG in large population studies.

scholarly journals IDENTIFICATION OF CANNABIMIMETIC MDMB(N)-073F METABOLITES IN URINE BY METHOD OF GAS CHROMATOGRAPHY WITH MASS SPECTROMETRIC DETECTION

2019 ◽  
Vol 7 (2) ◽  
pp. 70-83 ◽  
Author(s):  
S. S. Kataev ◽  
O. N. Dvorskaya ◽  
M. A. Gofenberg
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Acute Poisoning ◽  
Mass Spectrometric ◽  
Mass Spectrometric Detection ◽  
Urine Samples ◽  
Instrumental Method ◽  
Phase Extraction

Background. At the beginning of 2019, the use of a new representative of synthetic cannabimimetics of the methylbutanoate indazole carboxamides group, MDMB(N)-073F, was recorded in a number of regions in the Russian Federation. Characteristic features of the pharmacological effect, the clinical picture of MDMB(N)-073F poisoning have not been studied, the psychoactive effects produced by MDMB(N)-073F remain unexplored. In this regard, the study of the new cannabimimetic metabolism is an important aspect in establishing the fact of taking MDMB(N)-073F during expert studies of biological objects.The aim of the research is identifying metabolites of synthetic MDMB(N)-73F cannabimimetics in real urine samples using solid-phase extraction (SPE) and gas chromatography (GC) with mass spectrometric detection (GC-MS).Materials and methods. 10 urine samples were collected from March 15 to March 29, 2019. 8 urine samples were taken from the medical examination offices of the city of Yekaterinburg and the Sverdlovsk region from the persons examined for intoxication; 2 urine samples were obtained from the patients of the Sverdlovsk regional center of acute poisoning upon enrolment to the toxic-intensive care unit with a preliminary diagnosis of “acute poisoning by synthetic cannabimimetics”. In the research, SampliQ EVIDEX-200 mg – 3 ml (Agilent, USA) cartridges were used for the sample preparation; β-glucuronidase Type HP-2, From Helix Pomatia, 100000 U/ml (Sigma-ALDRICH CHEMI, Germany) was used for enzymatic hydrolysis. Gas chromatography – mass spectrometry with the use of Agilent 7820 gas chromatograph with Agilent 5975 mass selective detector (Agilent, USA) was used as an instrumental method of the analysis.Results. The metabolites that make it possible to establish the fact of taking MDMB(N)-073F cannabimimetics via urine screening procedure to detect the presence of narcotic and medicinal substances with the use of solid-phase extraction and gas chromatography methods with mass spectrometry, have been described. The major metabolites MDMB(N)-073F in the urine of smoking mixtures consumers have been identified. The metabolism of MDMB(N)-073F has been found to be mainly due to hydrolysis of the ester group, hydroxylation, oxidative defluorination and N-dealkylation. Most of the resulting metabolites are excreted in the urine in the conjugated form.Conclusion. Gas chromatographic and mass spectrometric characteristics of some derivatives of the main metabolites of the new synthetic MDMB(N)-073F cannabimimetic have been obtained. This data can be used in the practice of forensic chemical and chemical toxicological analysis.

Determination of Diclofenac in Urine Samples by Molecularly-Imprinted Solid-Phase Extraction and Adsorptive Differential Pulse Voltammetry

2007 ◽  
Vol 19 (15) ◽  
pp. 1555-1561 ◽  
Author(s):  
Laura Fernández-Llano ◽  
M. Carmen Blanco-López ◽  
M. Jesús Lobo-Castañón ◽  
Arturo J. Miranda-Ordieres ◽  
Paulino Tuñón-Blanco
Keyword(s):  
Solid Phase Extraction ◽  
Differential Pulse Voltammetry ◽  
Solid Phase ◽  
Differential Pulse ◽  
Urine Samples ◽  
Phase Extraction ◽  
Molecularly Imprinted ◽  
Pulse Voltammetry
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