Laser-based measurements of 18O/16O stable isotope ratios (δ18O) in wine samples

Stable isotope ratio measurements on highly enriched water samples by means of laser spectrometry.

We demonstrate the feasibility of using laser spectrometry (LS) to analyze isotopically highly enriched water samples (i.e., delta2H < or = 15,000/1,000, 18O < or = 1,200/1,000), as often used in the biomedical doubly labeled water (DLW) method to quantify energy metabolism. The method is an important extension of a recently developed infrared laser direct absorption spectrometer. The measureme...

Silicon Isotope Ratios in Cais: In-situ Laser-ablation Mc-icpms Measurements and Comparisons with Magnesium Isotope Ratios

Introduction: High-precision measurements of Mg/Mg by multiple-collector inductively coupled plasma-source mass spectrometry (MC-ICPMS) have been used recently in our laboratory to constrain the thermal history of calcium aluminum-rich inclusions (CAIs) [1]. Presence of primary zoning profiles in at least some CAIs points to supersolidus and subsolidus diffusion as important factors in controll...

Infrared Laser-based Method for Measuring Isotope Ratios

Use of stable isotope ratios for profiling of industrial ephedrine samples: application of hydrogen isotope ratios in combination with carbon and nitrogen.

The utility of hydrogen stable isotope ratio measurement by IR-MS for establishing the origin of ephedrine and pseudoephedrine (ephedrines), precursors of methamphetamine, was evaluated. There are two kinds of commercial semisynthetic ephedrines, one produced from molasses and the other from pyruvic acid. While the semisynthetic ephedrines derived from pyruvic acid cannot be discriminated from ...

Stable Isotope Application in Animal Nutrition Science

The application of stable isotope analysis (SIA) has become a standard scientific approach in Agricultural and Ecological researches and, more in general, in several disciplines such as biology, botany, zoology, organic chemistry, climatology, and nutrition. The main objectives of this paper are (1) to provide a simple definition of stable isotopes and (2) to illustrate analytical measurement m...