δ13C and δ18O values of carbonate in organic-rich samples such as soils, biofilms, lake sediments have been scarcely used so far paleo-environmental, biomineralization, or diagenetic studies because organic matter high proportions is suspected to alter isotope analysis. Yet, with the improvement analytical capabilities particular use CF-IRMS, this may not be an issue anymore. To evaluate this, ...

In our earlier publications we proposed the possibility of using new EIM–IRMS ® instrumental technique and analytical parameter δD n wine ethanol, which represents δ 2 H value non-exchangeable hydrogen stable isotope ratio in to improve detection illegal production practices such as addition sugar and/or water grape must prior alcoholic fermentation. This article shows a comparative performance...

Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), we have developed a simple method to isolate myosin heavy chain (MHC) and actin from small (60-80 mg) human skeletal muscle samples for the determination of their fractional synthesis rates. The amounts of MHC and actin isolated are adequate for the quantification of [13C]leucine abundance by gas chromatography-combusti...

Instrumentation and methods exist for highly precise analyses of the stable-isotopic composition of organic compounds separated by GC. The general approach combines a conventional GC, a chemical reaction interface, and a specialized isotope-ratio mass spectrometer (IRMS). Most existing GC hardware and methods are amenable to isotope-ratio detection. The interface continuously and quantitatively...

High-precision analysis of the 17O / 16O isotope ratio in water and water vapor is of interest in hydrological, paleoclimate, and atmospheric science applications. Of specific interest is the parameter 17Oexcess (117O), a measure of the deviation from a linear relationship between 17O / 16O and 18O / 16O ratios. Conventional analyses of 117O of water are obtained by fluorination of H2O to O2 th...

A commercial interface coupling liquid chromatography (LC) to a continuous-flow isotope ratio mass spectrometry (CF-IRMS) instrument was used to determine the δ(13) C of dissolved organic carbon (DOC) in natural waters. Stream and soil waters from a farmland plot in a hedgerow landscape were studied. Based on wet chemical oxidation of dissolved organics the LC/IRMS interface allows the on-line ...

Studies are conducted on silver metal oxide contacts on a purposed built apparatus to investigate the extent of contact erosion under opening (break) operations. The contacts are opened between 0.1 and 0.8 ms 1 at particular point-on-wave, tPOW, of the ac waveform. Current loading of up to 30 A rms, Irms, is investigated. Contact material deposition, as well as mass loss, is observed and is fou...

A commercial interface coupling liquid chromatography (LC) to a continuous-flow isotope ratio mass spectrometer (IRMS) was used to analyse δ 13 C of dissolved organic carbon (DOC) in natural waters. Stream and soil waters from a farmland plot in a hedgerow landscape were selected for application. Based on wet chemical oxidation of dissolved organics the LCIRMS interface allows on-line injection...

BACKGROUND Resistant starch sources, which are only partially digested in the small intestine, can be used to increase colonic availability of short-chain fatty acids. OBJECTIVE To study the characteristics of the fermentation of resistant starch, the digestion of resistant starch in the small intestine has to be quantified. We compared the metabolic fates of highly digestible cornstarch (DCS...

The use of gas chromatography (GC)-combustion (C)-isotope ratio mass spectrometry (IRMS) demonstrates that a single oral administration of dehydroepiandrosterone (DHEA, 100 mg) to a male subject significantly lowers the 13C content of etiocholanolone (Et) and androsterone (A) in the subject's urine. The difference in carbon isotope ratio (d13C per thousand) values between Et and A increases fro...