N is for Nitrogen #AtoZChallenge

N is for Nitrogen

Nitrogen is the most abundant gas in the Earth’s atmosphere. It is also an important component of the amino acids that make up proteins in the bodies of living organisms.

Isotopes of nitrogen fractionate according to trophic level, that is, where the organism lies on the food chain (more properly, the food web). This is the origin of the common saying in isotope geochemistry, “You are what you eat, plus a few permil.” For nitrogen, on average a consumer’s δ15N is 3‰ more positive than the organism that is being eaten (whether it be a plant or another animal).

This relationship of nitrogen isotopes in proteins can be used to determine predator-prey relationships between extinct animals, presuming that proteins are preserved.

M is for Magnet #AtoZChallenge

M is for Magnet

A common feature of mass spectrometers is a magnet. A strong magnetic field is necessary to separate the molecules of slightly different mass for measurement.

Not all mass spectrometers work in the exact same way, but all use powerful magnets to select atoms and molecules of specific masses so that it’s possible to measure the amount of the different isotopes of specific elements. The configuration of these magnets differs depending on the isotopes being measured.

Mass spectrometers such as the DeltaPlus XP here at SIREAL have a single magnet that splits a beam of ionized gas into two or three beams of different masses that are measured simultaneously. This makes it possible to calculate the ratios necessary for the delta values (see D is for delta).

L is for LIMS #AtoZChallenge

L is for LIMS

LIMS is an acronym that means “Laboratory Inventory Management System.” Because of the amount of data that laboratories such as ours must keep track of, using LIMS is necessary.

At SIREAL, we use LIMS for light stable isotopes that was developed at the Reston Stable Isotope Laboratory, part of the United States Geological Survey.

LIMS for light stable isotopes does more than just organize and store your data, it also contains all the necessary algorithms and does the necessary calculations to convert raw data from the mass spectrometer into usable isotopic results that can be compared among laboratories internationally.

K is for Cretaceous #AtoZChallenge

K is for Cretaceous

Cretaceous starts with a ‘C,’ so why is it K for Cretaceous? All the divisions of the Earth’s geological time scale have one- or two-letter designations, kind of like all the elements of the periodic table have a symbol (like C for carbon or Au for gold). The abbreviation for Cretaceous is K, from the German for chalk (kreide) and also because ‘C’ is also already used for Carboniferous.

For today’s installment, we’ll look a paper that utilizes stable oxygen isotopes from the teeth of a dinosaur to determine how fast the teeth grown.

Suarez, You, Suarez, Li, and Treischmann, 2017, Stable isotopes reveal rapid enamel elongation (amelogenesis) rates for the early Cretaceous iguanodontial dinosaur Lanzhousaruus magnidens, Nature Scientific Reports, v. 7: 15319 | DOI:10.1038/s41598-017-15653-6

Iguanodontians were herbivorous dinosaurs with tightly packed teeth optimized for chewing vegetation. These dinosaurs replaced their teeth continuously though life so that their chewing mechanism was always ready to go. Continue reading “K is for Cretaceous #AtoZChallenge”

J is for Jurassic #AtoZChallenge

The Jurassic Period was a span of time from approximately 201 million years ago to 145 million years ago. The Jurassic is part of the Mesozoic Era of Earth’s history, which is regarded as the “Age of Dinosaurs.”

Stable isotopes provide a tool for exploring ancient environments. For today’s A to Z installment, we present a recent application of stable isotopes to understand What the world was like during the Jurassic Period.

Alberti, M, Fursich, F.T., Abdelhady, A.A., and Andersen, N., 2017, Middle to Late Jurassic equatorial seawater temperatures and latitudinal temperature gradients based on stable isotopes of brachiopods and oysters from Gebel Maghara, Egypt: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 468, p. 201-313. Continue reading “J is for Jurassic #AtoZChallenge”

F is for Fractionation #AtoZChallenge

Fractionation is a measure of how different isotopes of the same element behave during chemical reactions.

Different isotopes of the same element all behave more-or-less the same way in chemical reactions. They all bond in the same places, to the same other atoms. They fit into the same spaces. However, because the different isotopes have slightly different masses (weight), there is a tiny difference in the strength of the bond when there’s a heavier isotope or a lighter isotope. This tiny difference results in the heavy isotopes being separated from the light isotopes in a process called fractionation. Continue reading “F is for Fractionation #AtoZChallenge”

E is for Elemental Analyzer #AtoZChallenge

An elemental analyzer (EA) is a device that measures the quantities of specific elements in a material. For example, if you want to know how much nitrogen, carbon, and sulfur are in your soil, you’d use an elemental analyzer.

Elemental analyzers are excellent additions to regular mass spectrometers. The process of measuring the amounts of different elements requires that the sample is converted to a gas. Typically, once the elemental analyzer is done with it, the gas is released as exhaust. With a mass spectrometer, the gas can then be measured for different isotopes of carbon, nitrogen, sulfur or whatever you’re interested in. Continue reading “E is for Elemental Analyzer #AtoZChallenge”