Isotope fingerprinting

Food and beverage products have a fingerprint, a unique chemical signature that allows the product to be identified. To visualize this fingerprint, IRMS can be used, identifying the isotope fingerprint of the product. The isotope fingerprint in food and beverage products is region or process specific, which means that products can be differentiated based on geographical region (cheese, coffee, sugar, fish and animal feeding areas), botanical processes (beans, seeds, olive oil, vanilla), soil and fertilization processes (fruits and vegetables) and fraudulent practices (sugar addition to honey, watering of wines and spirits). These processes can be traced using carbon, nitrogen, sulfur, oxygen and hydrogen isotopes, with their variations indicating the origin and history of food and beverage products.

• How can stable isotopes be used to determine origin and authenticity of food and beverage products?
• Tracing the origin of food using MC-ICP-MS
• Was my wine watered down?
• Is my tequila correctly labeled?
• Was my produce organically grown?
• Where does my roasted coffee come from?
• Where does my green coffee come from?
• Has my honey been sweetened?
• SOP for δ13C, δ2H and δ18O analysis of vanillin in vanilla extracts

• Is my sugar from cane or beet?
• Where did my wine come from?
• Where does my beef meat come from?
• Does my coconut water contain authentic coconut?
• Where is my rice really from?
• Is my Argan oil authentic?
• What is the source of my menthol?
• GC-MS-IRMS: Addressing authenticity of fish oils by carbon and hydrogen isotope fingerprints

Forensic investigations examine sample materials to determine how similar or different they are, or to identify the origin of the material. Identifying the difference in a material or where it comes from can be achieved because materials have a unique chemical signature, like a fingerprint. To visualize this fingerprint, IRMS is used, measuring the stable isotopes of sample material that are essentially chemically identical. Unlike other types of inferential evidence in forensic investigations (e.g., bite marks, impression marks from tires or footwear, handwriting), isotope measurements are quantitative empirical evidence that are reproducible and easy to validate. The application of isotope fingerprints to forensic investigations has become more commonplace because there is a need for a rigorous scientific foundation underpinned by sound analytical techniques. Application areas include forensic investigations on human, criminal, environmental, ecological, food and archaeological materials.

• How do isotope fingerprints support forensic investigations?
• Examples of IRMS being used in forensic settings?
• Which is the cultivation region of cocaine?
• Tracing human provenance using hydrogen and oxygen isotope fingerprints
• What were the dietary habits of humans and animals?

• Tracing origin of explosives using carbon, hydrogen and oxygen isotope fingerprints
• How do isotope fingerprints support doping control investigations?
• Combat emerging threats in drug abuse with isotope fingerprints
• Where does this wood come from?

As oil exploration is expensive, petroleum companies use multiple criteria for source identification, such as chemical and isotope fingerprinting, to meet decision on exploitation activities. Identification of sources can be achieved because petrochemical materials, just like other natural and synthetic materials, carry a unique chemical signature and we refer to this as the isotope fingerprint.

To visualize this fingerprint, IRMS is used. Application of isotope fingerprints in exploration and exploitation industry allows for differentiation of gas sources, migration, reservoir characterization, but also assessment of maturation and biodegradation processes. Isotope fingerprints of carbon, nitrogen, sulfur, oxygen and hydrogen are also used to address the influence of petrochemical exploration on environment. 

Nuclear applications, like nuclear safeguards, environmental control and nuclear fuel processing to generate nuclear energy, undergo very stringent regulations, requiring precise and accurate isotope analysis of uranium and other actinide elements. Nuclear safeguards and environmental control require ultimate detection systems to be able to find uranium and actinide isotopic signatures in very small samples like tissues. For nuclear power plants, it is crucial to use the correct amount and mixture of nuclear fuels for the nuclear fission process and as such requires precise and accurate ²³⁵U and ²³⁹Pu isotope information of the feed and product material.

Thermo Scientific isotope ratio mass spectrometers are ideally equipped for nuclear applications. The RPQ energy filter reduces the tailing of major isotopes onto neighboring minor isotopes, allowing extreme isotope ratios to be accurately determined. A tailored nuclear Multi Ion Counting package allows low abundance ²³⁴U and ²³⁶U to be determined at a fg level. 

Contamination control is critical in the semiconductor and high purity metal industries. In particular, inorganic impurities affect the electrical properties of the insulating and conducting layers from which semiconductor devices are made. Similarly, high purity metals such as copper, are important precursor materials for the synthesis of advanced materials, including compound semiconductors used in solar cells and superconducting ceramics. Trace element contamination can therefore reduce the manufacturing yield and operational reliability of semiconductor devices. To minimize contamination, process chemicals and the metal end product must be monitored for ultratrace (ng/L; ppt) levels of elemental impurities.

Trace elemental analysis can be achieved using a number of instruments in the Thermo Scientific isotope ratio mass spectrometer portfolio. These high sensitivity instruments are designed to have low detection limits ideal to monitoring ultratrace levels of elemental impurities whilst still maintaining a high sample through-put. 

• Routine analysis of 6N high purity copper
• High precision nickel alloy analysis
• Analysis of alumina powders
• High purity aluminum analysis by glow discharge mass spectrometry
• Analysis of solar cell silicon using glow discharge mass spectrometry
• GD-MS analysis of sulphur at the ultra-trace level
• Fast routine analysis of trace and ultra trace elements in zinc alloys by Glow Discharge Mass Spectrometry

• Full survey chemical analysis of thin films with pulsed fast flow GD-MS
• Sub-ppt level automated analysis of impurities in nitric acid–hydrogen peroxide solution via HR-ICP-MS
• Analysis of semiconductor grade mineral acids by sector field ICP-MS
• Determination of ultra-trace elements in semiconductor grade TMAH developer
• Determination of ultra-trace elements in liquid crystal
• Analysis of sulfuric acid using a single set of operating conditions with HR-ICP-MS

Isotope ratio mass spectrometers can also be used for battery research. One main problem of the lithium ion battery is the aging over time, and its loss of performance. Most of the aging parts in the electrolyte are organic based compounds. Coupling High Resolution ICP-MS to chromatography systems allows researchers to quantify unknown reaction products occurring as a result of aging within the electrolyte. Depth profiling techniques using Glow Discharge MS can be used to determine lithium migration into different cell components as the battery ages.