Radiocarbon
About the services
Welcome to the Radiocarbon Services page at the Yale Analytical and Stable Isotope Center (YASIC). Our mission is to provide high-quality radiocarbon dating services to support research in various scientific fields, from archaeology and geology to climate science. Our state-of-the-art facilities and experienced staff ensure precise and reliable radiocarbon measurements.
Research applications
Radiocarbon dating is instrumental in a wide array of research disciplines. Some example applications include:
- Environmental science: Tracking carbon cycles and environmental changes over millennia.
- Archaeology: Dating ancient human settlements, artifacts, and cultural remains.
- Paleoclimatology: Understanding past climate changes through analyzing sediment cores and peat bogs.
- Geology: Dating geological events such as volcanic eruptions and rock formations.
Radiocarbon dating services
At YASIC, we offer comprehensive radiocarbon dating services, including:
- AMS radiocarbon dating: Utilizing accelerator mass spectrometry (AMS) to precisely date small sample sizes.
- Sample pretreatment: Thorough sample preparation to remove contaminants and ensure accurate results.
- Data reporting: Detailed reports, including calibrated radiocarbon ages.
Turnaround time & pricing
- Standard service: Results are typically delivered within 4-6 weeks.
- Expedited service: Results available in as little as 2 weeks for an additional fee.
- Pricing: Our competitive pricing structure is based on sample analysis type and processing requirements.
For more information or to discuss your specific project needs, please contact us.
Available to Yale researchers & external researchers
Turnaround time
Standard service: Results are typically delivered within 4-6 weeks. Expedited service: Results available in as little as 2 weeks for an additional fee.
MICADAS radiocarbon instrument
YASIC is equipped with the highly advanced MICADAS (Mini Carbon Dating System) radiocarbon instrument developed by IonPlus. The ion source allows samples to be analyzed using the traditional graphite method or directly as a CO2 measurement. Generally, graphite has higher precision and accuracy, needing 1 mg of carbon per measurement. CO2 gas is measured directly with a gas introduction system (GIS mode) with an ideal target mass of 0.1 mg of carbon. The benefit of smaller target masses comes with a trade-off in somewhat lower precision and accuracy (particularly with older samples) due to limited counting time and statistics, which is not an issue in measuring graphite. YASIC’s setup allows for graphite measurement of solid organic and inorganic carbon and dissolved inorganic carbon; Gas measurements are restricted to solid organic carbon samples.
This cutting-edge technology provides several benefits:
- High sensitivity: Enables the dating of small samples with high precision.
- Rapid analysis: Offers faster turnaround times without compromising accuracy.
- Versatility: Can analyze a wide range of sample materials.
- Automated system: Enhances efficiency and reduces the likelihood of human error during analysis.
The MICADAS instrument is crucial in delivering reliable and precise radiocarbon dates, making it an invaluable asset for various research applications.
Sample analysis and peripheral preparation options
Precision and accuracy
Our MICADAS system's high sensitivity allows us to achieve exceptional precision and accuracy in radiocarbon dating. The typical precision is in the range of ±20-30 years for modern samples, and the system can detect radiocarbon dates to approximately 50,000 radiocarbon years with reliable accuracy.
Calibration methods
We recommend using internationally recognized calibration methods to convert radiocarbon years into calendar ages, typically using software such as OxCal or CALIB.
Sample types
Suitable for analysis:
- Charcoal and wood: Ideal for dating archaeological and geological samples.
- Shell and carbonate materials: Suitable for marine and estuarine environments.
- Textiles and paper: Suitable for dating historical artifacts and documents.
- Bone and antler: Requires collagen extraction; suitable for archaeological and paleoenvironmental studies.
Not suitable for analysis:
- Contaminated samples: Those exposed to modern carbon contamination or enriched 14C materials or spaces exposed to enriched radiocarbon.
- Waterlogged samples: Often degraded and can provide unreliable results.
- Highly alkaline or acidic samples: Chemical conditions that can alter the carbon content.
- Synthetic materials: Plastics and modern composites do not contain naturally occurring carbon.
Specifications
Sample preparation
Proper sample preparation is critical to obtaining accurate and reliable radiocarbon dating results. Here are the guidelines to ensure your samples are ready for analysis.
- Minimal handling: Handle samples as little as possible to avoid contamination.
- Clean tools: Process the samples using clean, non-reactive tools (e.g., stainless steel or ceramic).
- Storage: Store samples in clean, dry conditions using appropriate containers (e.g., aluminum foil and glass vials).
- Labeling: Label each sample with identification codes and relevant information.
- Documentation: Provide detailed documentation for each sample, including sample type, location, and context of collection.
Specific sample types
- Charcoal and wood: Remove any adhering soil or foreign material. Avoid direct contact with hands.
- Bone and antler: Clean to remove dirt and consolidants; do not use glue or preservatives.
- Shell and carbonate materials: Rinse with deionized water; avoid acidic cleaning agents when possible.
- Peat, soil, and sediments: Air-dry and store in a paper bag or glass vial.
- Textiles and paper: Keep in dry conditions; avoid any chemical treatments.
General sample preparation guidelines
- Minimal handling: Handle samples as little as possible to avoid contamination.
- Clean tools: Clean, non-reactive tools (e.g., stainless steel or ceramic) are used to process the samples.
- Storage: Store samples in clean, dry conditions using appropriate containers (e.g., aluminum foil, glass vials).
- Labeling: Clearly label each sample with identification codes and relevant information.
- Documentation: Provide detailed documentation for each sample, including sample type, location, and context of collection.
Acid-base-acid cleaning
The acid-base-acid (ABA) method is used to remove contaminants from samples, especially those that have been buried or exposed to possible contamination. This method is crucial for ensuring the accuracy of radiocarbon dating results.
ABA cleaning is typically necessary for samples like wood, charcoal, and other organic materials that may have absorbed humic acids from the soil. The process helps to remove these contaminants without affecting the sample's original carbon content.
Steps
1. Acid wash:
- Soak the sample in 1M hydrochloric acid (HCl) at room temperature for 1-2 hours.
- Rinse thoroughly with deionized water to remove all acid.
2. Base wash:
- Immerse the sample in 0.1M sodium hydroxide (NaOH) for 1-2 hours. This step removes any remaining humic acids.
- Rinse thoroughly with deionized water to ensure no base remains.
3. Acid wash (repeated):
- Soak the sample again in 1M hydrochloric acid (HCl) for 1 hour to neutralize the effects of the base and remove any remaining contaminants.
- Final rinse with deionized water to ensure the sample is chemical-free.
- Dry the sample at a low temperature (~50°C).
This method can be adjusted depending on the specifics of the sample and the potential contaminants present.
Calcium carbonate shells & foraminifera treatment
- Foraminifera shells: These shells from single-cell foraminifera are used to study past seawater conditions. They are too small for individual carbon-14 testing, so they are collected and sorted by species.
- Cleaning shells: Foraminifera often have secondary authigenic carbonates on their surface, which must be removed before analysis. These carbonates are typically visible under a microscope and can be cleaned off using 0.1 N HCl for up to 10 seconds in an ultrasonic bath and rinsed with deionized water. This method also applies to other sample types (the acid strength must be adjusted based on the sample's level of alteration).
- Diagenetic alteration: When dating older macrofossils, care must be taken to check for diagenetic alteration of the carbonate. Assessing diagenetic alteration is crucial for fossil coral samples, where aragonite can alter to calcite over time, affecting the accuracy of carbon-14 dating.
Ethical & legal
Ethical and legal considerations & restrictions with culturally sensitive and art samples
YASIC recognizes the importance of ethical handling and adherence to legal regulations for all samples, especially culturally sensitive items and art samples. Please ensure compliance with national and international regulations and provide documentation of permissions and responsibility for ethical handling.
Specific restrictions
- Cultural artifacts: Requires proper documentation and permission from relevant authorities before analysis. Follow applicable laws and guidelines for the handling and exporting of cultural heritage items.
- Art samples: We require confirmation that the analysis will not harm or devalue the items for artworks and historical documents. A conservator's assessment may be necessary.
- Consent and provenance: Ensure that all submissions of culturally sensitive and art samples have clear provenance and that appropriate consent has been obtained.
- Minimal destructive analysis: We use less invasive techniques to preserve the integrity of culturally significant artifacts where possible.
If your samples fall within these categories, please contact us in advance to discuss your specific requirements and any additional preparations needed.
Rates
Pricing: Our competitive pricing structure is based on sample analysis type and processing requirements.