Human urine certified reference material CZ 6010: creatinine and toluene metabolites (hippuric acid and o-cresol) and a benzene metabolite (phenol)

Šperlingová, Ilona; Dabrowská, Ludmila; Stránský, Vladimír; Kučera, Jan; Tichý, M

doi:10.1007/s00216-006-0708-7

Cited by 8 publications

(6 citation statements)

References 17 publications

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“…The aliquots used for this study were those stored at −40 °C for up to a maximum of 8 years prior to 1 H NMR analysis. Our in-house data and other studies 41 show that urine specimens stored at −40 °C show minimal changes in the metabolic profiles for up to 6 years. Urine specimens were thawed completely before mixing 500 µL of urine with 250 µL of phosphate buffer (0.2M) for the stabilization of urinary pH 7.4 (± 0.5), and 75 µL of sodium 3-trimethylsilyl-(2,2,3,3- 2 H 4 )-1-propionate (TSP) in D 2 O (final concentration 0.1mg/mL) solution for chemical shift referencing of TSP (δ 0.0).…”

Section: Methodssupporting

confidence: 71%

Metabolic Profiling and Population Screening of Analgesic Usage in Nuclear Magnetic Resonance Spectroscopy-Based Large-Scale Epidemiologic Studies

Loo

Coen²,

Ebbels³

et al. 2009

Anal. Chem.

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The application of a 1 H NMR spectroscopy based screening method for determining the use of two widely available analgesics (acetaminophen and ibuprofen) in epidemiologic studies has been investigated. We used samples and data from the cross-sectional INTERMAP Study involving participants from Japan (n=1,145), China (n=839), UK (n=501) and USA (n=2,195). An orthogonal projection to latent structures discriminant analysis (OPLS-DA) algorithm with an incorporated Monte Carlo re-sampling function was applied to the NMR dataset to determine which spectra contained analgesic metabolites. OPLS-DA pre-processing parameters (normalization, bin width, scaling and input parameters) were assessed systematically to identify an optimal acetaminophen prediction model. Subsets of INTERMAP spectra were examined to verify and validate the presence/ absence of acetaminophen/ibuprofen based on known chemical shift and coupling patterns. The optimized and validated acetaminophen model correctly predicted 98.2% and the ibuprofen model correctly predicted 99.0 % of the urine specimens containing these drug metabolites. The acetaminophen and ibuprofen models were subsequently used to predict the presence/absence of these drug metabolites for the remaining INTERMAP specimens. The acetaminophen model identified 415 of 8,436 spectra containing acetaminophen metabolites while the ibuprofen model identified 245 of 8,604 spectra containing ibuprofen metabolites from the global dataset. The NMRbased metabolic screening strategy provides a new objective approach for evaluation of self-reported medication data and is extendable to other aspects of population xenometabolome profiling.

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Section: Methodssupporting

confidence: 71%

Metabolic Profiling and Population Screening of Analgesic Usage in Nuclear Magnetic Resonance Spectroscopy-Based Large-Scale Epidemiologic Studies

Loo

Coen²,

Ebbels³

et al. 2009

Anal. Chem.

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“…Toluene is one the most widely used industrial organic chemicals, with exposure leading to acute and chronic respiratory effects, functional alteration of the central nervous system, and chromosome aberrations [37][38][39]. The proposed major pathway (Fig.…”

Section: Model Urinary Toluene Metabolite Separationmentioning

confidence: 99%

Biologically driven neural platform invoking parallel electrophoretic separation and urinary metabolite screening

et al. 2012

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This work reveals a computational framework for parallel electrophoretic separation of complex biological macromolecules and model urinary metabolites. More specifically, the implementation of a particle swarm optimization (PSO) algorithm on a neural network platform for multiparameter optimization of multiplexed 24-capillary electrophoresis technology with UV detection is highlighted. Two experimental systems were examined: (1) separation of purified rabbit metallothioneins and (2) separation of model toluene urinary metabolites and selected organic acids. Results proved superior to the use of neural networks employing standard back propagation when examining training error, fitting response, and predictive abilities. Simulation runs were obtained as a result of metaheuristic examination of the global search space with experimental responses in good agreement with predicted values. Full separation of selected analytes was realized after employing optimal model conditions. This framework provides guidance for the application of metaheuristic computational tools to aid in future studies involving parallel chemical separation and screening. Adaptable pseudo-code is provided to enable users of varied software packages and modeling framework to implement the PSO algorithm for their desired use.

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“…Main studies of hippuric and methylhippuric acid focus their identification and quantification by gas chromatography or high performance liquid chromatography resolution as direct indicators of toluene levels and xylene isomers in urine samples, respectively. Therefore, its determination to know the levels of contamination is essential, especially in the workers of the chemical industry (Sperlingová et al, 2007;Antunes et al, 2013). Thus, quantification of hippuric and methylhippuric acid in urine is actually used as a diagnostic marker of exposure to toluene and xylene.…”

Section: Introductionmentioning

confidence: 99%

4-Methyl Hyppuric Acid: A Case of Polymorphism and Solvatomorphism

Delgado¹,

Guillén²,

Mora³

2019

PTQ

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Polymorphism is known as the ability of a solid material to exist in more than one form or crystal structure, with important applications in the preparation of active pharmaceutical ingredients. Characterization of different polymorphs of the specific metabolite of 4-xylene can contribute to the chemical and pharmaceutical industry. Polymorphism is of particular importance in industrial processes, where different physical properties of polymorphic forms can substantially alter the viability and quality of a manufactured product. This is particularly so for the design and production of drugs in the pharmaceutical industry, as varying physical properties between different polymorphs can affect shelf life and durability, solubility, as well as bioavailability and manufacturing of the drug. The crystallization, spectroscopic and X-ray diffraction characterization of two polymorph and one solvatomorph of 4-methylhippuric acid are presented. These compounds crystallizes in different crystalline systems. Polymorph I (4mH-I) crystalize in an orthorhombic cell with space group P212121. Polymorph II (4mHII) crystallizes in a monoclinic space group P21/c. Solvatomorph (4mH-S) crystallizes in a triclinic P-1 cell. All polymorphs crystallize in neutral form. The crystal packing of the three compounds are governed by hydrogen bonds intermolecular interactions of the type N--H···O and O--H···O forming tridimensional networks.

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Human urine certified reference material CZ 6010: creatinine and toluene metabolites (hippuric acid and o-cresol) and a benzene metabolite (phenol)

Cited by 8 publications

References 17 publications

Metabolic Profiling and Population Screening of Analgesic Usage in Nuclear Magnetic Resonance Spectroscopy-Based Large-Scale Epidemiologic Studies

Metabolic Profiling and Population Screening of Analgesic Usage in Nuclear Magnetic Resonance Spectroscopy-Based Large-Scale Epidemiologic Studies

Biologically driven neural platform invoking parallel electrophoretic separation and urinary metabolite screening

4-Methyl Hyppuric Acid: A Case of Polymorphism and Solvatomorphism

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