Integrated gas chromatography-mass spectrometry

Traceability of VOCs in tire inner liner by chromatography-mass spectrometry

Many parts of the vehicle cabin generate volatile organic compounds (VOCs), and some are hazardous and/or odorous to humans. In this study, VOCs in the inner liner of automobile spare tire, including raw rubbers and resins, were detected by gas chromatography-mass spectrometry (GC-MS) coupled with an extracting method of static headspace sampling (SHS). The results demonstrated that the sources of VOCs can be traced back to raw rubbers and resins: alkylphenol resins can release a large amount of 2,4,4-trimethyl-1-pentene and 2,2,4,6,6-pentamethyl-3-heptene; chlorobutyl rubber (CIIR) contained 3-methyl-pentane, and methyl-cyclopentane, and these VOCs are odorous. When alkylphenol resin and natural rubber (NR) with low VOCs were used to replace the corresponding resin and NR in the initial formulation, the total volatile organic compounds (TVOCs) in the inner liner could be reduced. We expected that the information gained from this work could provide a basic reference for the manufacture of environmental-friendly tire products.

A timeline of stable isotopes and mass spectrometry in the life sciences

This review retraces the role of stable isotopes and mass spectrometry in the life sciences. The timeline is divided into four segments covering the years 1920-1950, 1950-1980, 1980-2000, and 2000 until today. For each period methodic progress and typical applications are discussed. Application of stable isotopes is driven by improvements of mass spectrometry, chromatography, and related fields in sensitivity, mass accuracy, structural specificity, complex sample handling ability, data output, and data evaluation. We currently experience the vision of omics-type analyses, that is, the comprehensive identification and quantification of a complete compound class within one or a few analytical runs. This development is driven by stable isotopes without competition by radioisotopes. In metabolic studies as classic field of isotopic tracer experiments, stable isotopes and radioisotopes were competing solutions, with stable isotopes as the long-term junior partner. Since the 1990s the number of metabolic studies with radioisotopes decreases, whereas stable isotope studies retain their slow but stable upward tendency. Unique fields of stable isotopes are metabolic tests in newborns, metabolic experiments in healthy controls, newborn screening for inborn errors, quantification of drugs and drug metabolites in doping control, natural isotope fractionation in geology, ecology, food authentication, or doping control, and more recently the field of quantitative omics-type analyses. There, cells or whole organisms are systematically labeled with stable isotopes to study proteomic differences or specific responses to stimuli or genetic manipulation. The duo of stable isotopes and mass spectrometry will probably continue to grow in the life sciences, since it delivers reference-quality quantitative data with molecular specificity, often combined with informative isotope effects. © 2016 Wiley Periodicals, Inc. Mass Spec Rev 36:58-85, 2017.