If you hear anyone from Picarro talking about radical insights into the global carbon, water and nitrogen cycles – “essentially the building blocks of all life on Earth” – we are referring to the information that our CRDS technology provides about the molecules that comprise these cycles - notably, their stable isotope signatures.

What are isotopes and what do you mean by stable isotopes?

Isotopes are any of two or more forms of a chemical element that have the same number of protons in the nucleus (i.e. the same atomic number), but have different numbers of neutrons in the nucleus (different atomic weights.) Stable isotopes are chemical isotopes that are not radioactive – that is, they do not decay spontaneously with time. Every element has known isotopic forms and isotopes of a single element possess almost identical properties.

Compounds made from elements such as carbon, hydrogen, nitrogen and oxygen generally contain varying percentages of each element’s isotope. The specific ratio is dictated by conditions associated with the compound’s formation, including biochemical processes that brought it into being and the geographic place of origin that imparts a unique fingerprint on each element. This is what we call nature’s barcode.

Picarro can measure and quantify stable isotope ratios with high precision to unravel the biochemical processes encoded in a sample. Here are just a few of the innumerable uses of stable isotope data:

Water Isotopes

• Identifying the source of water
• Tracking food to its point of production and revealing adulteration
• Identifying growth condition of plant systems
• Exploring climate history by analyzing ice cores
• Understanding the flow of ocean waters

Carbon Isotopes

• Understanding how carbon is exchanged between the atmosphere and ecosystems, such as oceans, soil and plants
• Monitoring carbon geo-sequestration sites
• Verifying food origin and authenticity
• Substantiating supply chain integrity
• Determining the carbon source in dissolved carbonates
• Identifying and partitioning the sources of fugitive methane gas emissions

Nitrogen Isotopes

• Distinguishing N₂O production sources from nitrification and de-nitrification on the basis of isotopomer abundances
• Identifying and partitioning N₂O emission sources
• Understanding how nitrogen is exchanged between the atmosphere and ecosystems, such as oceans, soil and plants
• Understanding dissolved nitrogen in aquatic systems