Heart-cut multidimensional gas chromatography coupled to selective mass spectrometric detection (H/C MDGC-MS-MS) was shown to be a suitable combination for analysis of the key component for the wine off-flavor named "atypical aging off-flavor" (german: "Untypische Alterungsnote", UTA), 2-aminoacetophenone (2-AAP). Headspace solid phase microextraction (HS-SPME) was applied as an easy to automate sample preparation step suiting routine control situations. During method development two critical aspects were found, of which one is the chemical degradation of the neat substance, leading to signal reduction and a false response behavior. A second aspect is the pH stability of the deuterated isotopologue 1-(2-aminophenyl)-2,2,2-trideuterio-ethanone (2-AAP-d3) used for quantification via a stable isotope dilution assay. Despite an earlier suggestion to increase the extractable amount of 2-AAP and its isotopic standard in the headspace, alkalization of 2-AAP-d3 containing aqueous samples were found to be critical. In such a milieu a deuterium exchange can then cause erroneous quantitative results. The method proposed in our study thus uses native wine pH conditions and proved to be suitable for routine control with respect to the detection of the "atypical aging off-flavor" in wine at concentration levels below its sensory threshold of about 1μgL. Good linearity was obtained in the calibrated range from 0.1-8μgL (y=1,2338x+0,1029, R=0,9985) with limits of detection or quantification being 0.01 and 0.14μg/L, respectively.
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http://dx.doi.org/10.1016/j.chroma.2016.11.029 | DOI Listing |
J Chromatogr A
September 2024
College of Pharmaceutical Sciences and Jiangsu Key Laboratory of Neuropsychiatric Diseases, Soochow University, Suzhou, Jiangsu, 215021, China. Electronic address:
Sulodexide, a heparinoid medicine, is wildly used in clinic for prophylaxis and treatment of thromboembolic diseases and diabetic nephropathy. Despite its widespread use, the structure of Sulodexide remains poorly understood. It consists of various polysaccharides characterized by differing sugar compositions, linkages, and sulfonation patterns, yet they share common features such as strong hydrophilicity, high native charges, and considerable polydispersity, posing significant challenges for conventional chromatographic and online mass spectrometry (MS) characterization.
View Article and Find Full Text PDFJ Chromatogr A
January 2024
Department of Analytical Chemistry, Laboratory for Flavor Analysis and Enology (LAAE), Faculty of Sciences, Instituto Agroalimentario de Aragón (IA2), Universidad Zaragoza, Zaragoza E-50009, Spain.
A quantitative analytical method capable of determining the concentrations of 81 aroma-relevant wine volatiles covering nine orders of magnitude was developed and validated in this study. The method is based on stir bar sorptive extraction (SBSE) of 200 μL of wine diluted with 1.8 mL NaCl brine with pH 3.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
July 2023
Department of Chemical and Biological Engineering, Mappin Street, University of Sheffield, S1 3JD, UK. Electronic address:
Oligonucleotides are commonly analysed using one dimensional chromatography (1D-LC) to resolve and characterise manufacturing impurities, structural isomers and (in respect to emerging oligonucleotide therapeutics) drug substance and drug product. Due to low selectivity and co-elution of closely related oligonucleotides using 1D-LC, analyte resolution is challenged. This leads to the requirement for improved analytical methods.
View Article and Find Full Text PDFJ Sep Sci
September 2023
Department of Biomedical, Dental, Morphological and Functional Imaging Sciences, University of Messina, Messina, Italy.
Separation science plays a crucial role in the isolation of novel compounds contained in complex matrices. Yet their rationale employment needs preliminary structure elucidation, which usually requires sufficient aliquots of grade substances to characterize the molecule by nuclear magnetic resonance experiments. In this study, two peculiar oxa-tricycloundecane ethers were isolated by means of preparative multidimensional gas chromatography from the brown alga species Dictyota dichotoma (Huds.
View Article and Find Full Text PDFJ Chromatogr A
May 2023
Shimadzu Corporation, 3-9-4, Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0237, Japan.
Decades ago, multi-column GC was developed for separating analytes which cannot be separated with a single column by switching the flow channels and introducing them into multiple columns. Formerly, a channel switching system consisted of stainless-tube-type packed columns and multi-port switching valves which were connected by stainless-steel pipes. These systems utilizing packed columns are still widely used today, mainly for gas analysis, especially for refinery gas analysis and natural gas analysis related to oil refining.
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