Abstract An analytical method using gas chromatography isotope ratio mass spectrometry (GC-IRMS) combined with solid phase micro-extraction (SPME) was developed to measure the δ 13C values of six typical volatiles commonly occurring in wine (isoamyl acetate, 2-octanone, limonene, 2-phenylethanol, ethyl octanoate and decanoate) for first time. SPME selected a divinylbenzene/carboxen/polydimethyl...

Image-reject mixers (IRMs) and single-sideband mixers (SSMs) play a key role in many of today’s microwave and rf systems [1, 2, 3]. IRMs and SSMs reduce system cost and complexity by removing the need for expensive preselection, and one or more stages of upor downconversion. IRMs simplify downconversion by employing phase-cancellation techniques to separate the downconverted products resulting ...

A variety of reference models such as CMMI, COBIT or ITIL support IT organizations to improve their processes. These process improvement reference models (IRMs) cover different domains such as IT development, IT Services or IT Governance but also share some similarities. As there are organizations that address multiple domains and need to coordinate their processes in their improvement we prese...

Compound-specific isotope analysis (CSIA) by isotope ratio mass spectrometry (IRMS) following on-line combustion (C) of compounds separated by gas chromatography (GC) is a relatively young analytical method. Due to its ability to measure isotope distribution at natural abundance level with great accuracy and high precision, GC-C-IRMS has increasingly become the method of choice in authenticity ...

This paper discusses some of the recent improvements in instrumentation used for stable isotope tracer measurements in the context of measuring retinol stores, in vivo. Tracer costs, together with concerns that larger tracer doses may perturb the parameter under study, demand that ever more sensitive mass spectrometric techniques are developed. GCMS is the most widely used technique. It has hig...

A variety of process improvement reference models (IRM) like CMMI, COBIT or ITIL support IT organizations. These reference models cover different domains such as IT development, IT Services or IT Governance but also share some similarities. There are organizations that address multiple domains and want to use different IRMs. As IRMs are described in different structures and are using different ...

A survey of the multi-stable isotopic composition of an active pharmaceutical ingredient (API), naproxen, was performed to assess the potential of Isotope Ratio Mass Spectrometry (IRMS) to distinguish the provenance of APIs. Twenty-six lots of naproxen from six manufacturers representing four countries (Italy, India, Ireland, and the USA) were analyzed for three isotope ratios (13C/12C, 18O/16O...

Nondispersive infrared spectrometry (NDIRS) was used to detect Helicobacter pylori infection with the 13C-urea breath test. The results were compared with those of standard isotope ratio mass spectrometry (IRMS). Both methods accurately distinguished between H. pylori-positive and H. pylori-negative individuals. The results demonstrate that NDIRS technology is accurate and therefore of equal va...

RATIONALE The hydrogen and oxygen isotopic analyses (δ(2)H and δ(18)O values) of water trapped within speleothem carbonate (fluid inclusions) have traditionally been conducted utilizing dual-inlet isotope ratio mass spectrometry (IRMS) or continuous-flow (CF)-IRMS methods. The application of cavity ring-down spectroscopy (CRDS) to the δ(2)H and δ(18)O analysis of water in fluid inclusions has b...

Accurate determinations of stable isotope ratios require a calibration using at least two reference materials with different isotopic compositions to anchor the isotopic scale and compensate for differences in machine slope. Ideally, the delta values of these reference materials should bracket the isotopic range of samples with unknown delta values. While the practice of analyzing two isotopica...