heavy isotope

heavy isotope

a stable atom in which there are more neutrons than in the normal isotope of the element, giving it a greater mass. For example, 15N is the heavy isotope, 14N the common form.
References in periodicals archive ?
Previous spectrometer devices lacked the sensitivity to detect this heavy isotope in the atmosphere.
To produce good-quality weapons-grade plutonium--with a concentration of the most-important heavy isotope (Pu240)--a short "burnup" fuel cycle is employed, meaning that the reactor fuel rods are removed earlier than they would be if the reactor was utilized to produce electricity.
The probable age range of these fish suggests that an ontogenetic diet shift associated with maturation is difficult to extrapolate from these data because the trend of increasing heavy isotope values is confounded by changes in prey availability, by increases in fish prey capture efficiency with seatrout size, and by the potential variability of carbon and nitrogen sources within the Mississippi Sound and its subestuaries.
Tritium is a heavy isotope of hydrogen but it decays radioactively at the rate of 5.
Therefore in each case we have two possibilities, either muon can escape and proton is captured by heavy isotope to form a Helium ion or a mu-helium ion is formed.
With triple-stage validation (both mass spec & HPLC) and over 10 years of successful synthesis, ClearPoint[TM] peptides are the proven solution for optimum quality heavy isotope labeled peptides.
Distinct heavy isotope ratios characterize all three sites and show regional differentiation broadly consistent with geological expectations.
where i is the heavy isotope of the element and E represents the element of interest (carbon, nitrogen, or sulfur).
As an example, a sulfur crystal growing from a fluid will incorporate preferentially the heavier isotope, so that the crystals are enriched in the heavy isotope compared to the liquid, albeit only by a few tenths of a percent (Kyser, 1987).
The liquid chromatography coupled mass spectrometer will be used to measure peptides from complex trypsin digested protein samples pre-spiked with heavy isotope labelled protein standards in high multiplexes, as well as quality evaluation of protein standards performed in intact protein mode.
But when astronomers spectroscopically analyzed the water sublimating (vaporizing) from several bright comets such as Halley, Hyakutake, and Hale-Bopp, they found that the hydrogen in the water had only about half the hydrogen-to-deuterium ratio (deuterium is a heavy isotope of hydrogen) as the water in Earth's oceans.