Light Stable Isotope Ratio Analysis
At Brooks Applied Labs, we specialize in Gas-Source Isotope Ratio Mass Spectrometry (IRMS) for the precise analysis of light stable isotopes: hydrogen, carbon, nitrogen, oxygen, and sulfur. These isotopes carry unique signatures influenced by environmental and biological processes:
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- Hydrogen & Oxygen: Shaped by precipitation and climatic conditions.
- Carbon: Influenced by photosynthetic pathways and plant productivity.
- Nitrogon & Sulfur: Reflective of substrates, including fertilizers and soil sources.
Applications in Isotope Analysis
- Carbon Isotopes: Sugar Adulteration
Carbon isotopes can differentiate between C3 and C4 plants, based on their photosynthetic processes:
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- C3 plants (e.g., coconut): Preferentially use the lighter carbon-12 isotope.
- C4 plants (e.g., sugarcane): Show less discrimination between carbon-12 and carbon-13.
The isotopic difference between C3 and C4 plants is ~20 parts per thousand, a substantial range in stable isotope geochemistry. Our laboratory achieves a precision of ±0.5‰ for carbon isotope ratios.
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- Case Study: We analyzed coconut water for carbon isotope composition, revealing clear adulteration with C4 sugars, inconsistent with the native C3 profile of coconut-derived sugars.
- Nitrogen Isotopes: Fertilizer Tracing
Nitrogen isotopes distinguish between crops grown with synthetic versus organic fertilizers:
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- Synthetic fertilizers: Lower nitrogen-15 content.
- Organic fertilizers: Enrich crops with nitrogen-15, creating a difference of ~5‰.
Our nitrogen isotope ratio precision is ±0.5‰.
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- Case Study: Analyzing cinnamon samples revealed most were grown using synthetic fertilizers, as indicated by nitrogen isotope composition.
- Oxygen Isotopes: Geolocation
Oxygen isotopes serve as a robust geolocation tool, reflecting local precipitation patterns influenced by air temperature and proximity to oceans. Global agricultural regions exhibit a ~20‰ variation in oxygen isotopes. Our laboratory achieves a precision of ±0.5‰ for oxygen isotope ratios.
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- Case Study: We analyzed coconut water for oxygen isotope composition, confirming its stated origin in Thailand.
Sample Requirements
We require minimal material for comprehensive isotopic analysis:
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- Carbon: 100 µg
- Nitrogen: 100 µg
- Oxygen: 150 µg
This enables complete analysis of all three isotopes with just 10 mg of sample material.
For more information on our methods and applications, please contact us. Discover how our precision isotope analysis can meet your project needs.