A gas chromatographic method has been developed to determine the following metabolites in urine simultaneously if necessary: hippuric acid from toluene or styrene; 3- and 4-methyl hippuric acids from xylenes; phenylglyoxylic acid and mandelic acid from styrene. Heptadecanoic acid is added to the urine as an internal standard and after ethyl acetate extraction from acidic solution, the trimethylsilyl (TMS) derivatives of the metabolites are formed and simultaneously analysed by gas chromatography on 3% OV-1 on 80/100 gas chrom Q (flame ionisation detector).
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http://dx.doi.org/10.1136/oem.35.1.56 | DOI Listing |
Clin Rheumatol
January 2025
Department of Rheumatology, Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, People's Republic of China.
Introduction/objectives: Sjogren's syndrome (SS) is a chronic inflammatory and difficult-to-treat autoimmune disease. Timosaponin AIII (TAIII), a plant-derived steroidal saponin, effectively inhibits cell proliferation, induces apoptosis, and exhibits anti-inflammatory properties. This study explored the mechanisms of action of TAIII in SS treatment by studying gut microbiota and short-chain fatty acids (SCFAs) using fecal metabolomics.
View Article and Find Full Text PDFAnal Methods
November 2017
College of Environmental and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063, China.
A novel method was established using a restricted access material combined with a molecularly imprinted polymer (RAM-MIP) as the sorbent material in solid phase extraction (SPE) for clean-up of α-endosulfan, β-endosulfan, endosulfate, endosulfan-ether, endosulfan lactone, heptachlor, heptachlor--epoxide, and heptachlor--epoxide in pork and gas chromatography (GC) for determination. The RAM-MIP was prepared by precipitation polymerization by using endosulfan as the template, methacrylic acid (MAA) as the monomer, glycidyl methacrylate (GMA) as the pro-hydrophilic co-monomer, ethylene glycol dimethacrylate (EGDMA) as the crosslinker, azobisisobutyronitrile (AIBN) as the initiator, and toluene as the porogen. Ultraviolet spectroscopy (UV) and H-nuclear magnetic resonance (H-NMR) analysis verified that MAA interacted specifically with endosulfan in a ratio of 1 : 1 in the pre-polymerization solution.
View Article and Find Full Text PDFTalanta
January 2025
Institute of Chemistry of Renewable Resources, Department of Chemistry, BOKU University, Konrad-Lorenz-Straße 24, 3430, Tulln, Austria. Electronic address:
Chromatographic separations in combination with spectroscopic detectors are a main pillar of today's analytical chemistry. The recorded spectroscopic data is usually not shown in a typical chromatogram, therefore the contained additional information cannot be accessed readily by the analyst and is inspected in tedious additional routines, such as separate database searches. We developed a method to add colors to gas chromatograms with mass spectral detection.
View Article and Find Full Text PDFJ Pharm Biomed Anal
January 2025
Key Laboratory of Forensic Medicine, Ministry of Justice, Shanghai Forensic Service Platform, Shanghai Key Laboratory of Forensic Science, Academy of Forensic Science, Guangfu West Road 1347, Shanghai 200063, China. Electronic address:
Etomidate and its structural analogues, which have anesthetic effects, are classified as controlled psychotropic drugs. Electronic cigarettes (e-cigarettes) have become more and more popular. With the increase of adding etomidate and its analogues to electronic liquids (e-liquids), there is a trend of abuse, which is a tough problem urgently need to be solved.
View Article and Find Full Text PDFOpen Med (Wars)
January 2025
Department of Toxicological Chemistry, National Poison Control Center, Military Medical Academy, Belgrade, 11000, Serbia.
Introduction: Qualitative and quantitative testing of ethanol in samples is an important analytical procedure that provides accurate, precise, and reliable results. Given the complexity of the issue, obtaining a realistic picture of lifelong alcoholemia requires supporting blood ethanol findings with analyses of alternative samples, primarily vitreous humor (VH).
Objective: The objective of this study was to develop and validate a headspace gas chromatography with flame ionization detection (HS/GC-FID) method for determining ethanol concentration in VH.
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