scholarly journals Developments in Radiocarbon Technologies: From the Libby Counter to Compound-Specific AMS Analyses

Radiocarbon ◽  
2009 ◽  
Vol 51 (1) ◽  
pp. 45-78 ◽  
Author(s):  
Pavel P Povinec ◽  
A E Litherland ◽  
Karl F von Reden
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Accelerator Mass Spectrometry ◽  
Liquid Scintillation ◽  
Measuring Techniques ◽  
Beta Counting ◽  
The Future ◽  
Recent Developments

We review developments in radiocarbon measuring techniques from the Libby counter through proportional gas counters and liquid scintillation spectrometers to the more recent developments of accelerator mass spectrometry (AMS), followed by a coupling of gas chromatography with AMS for compound-specific 14C analyses. While during the first 60 yr of 14C measurements beta counting, specifically gas counting, was the dominant technique, in the future of 14C science AMS will be the dominant technology.

scholarly journals A Review of the Radiocarbon Dates for the Afanasyevo Culture (Central Asia): Shifting Towards the “Shorter” Chronology

Radiocarbon ◽  
2018 ◽  
Vol 61 (1) ◽  
pp. 243-263 ◽  
Author(s):  
Andrey V Poliakov ◽  
Svetlana V Svyatko ◽  
Nadezhda F Stepanova
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Liquid Scintillation Counting ◽  
Liquid Scintillation ◽  
Scintillation Counting ◽  
Radiocarbon Dates ◽  
Archaeological Data ◽  
Depth Analysis ◽  
Over Time ◽  
Ams Dates

ABSTRACTThis article provides a summary and in-depth analysis of all existing radiocarbon (14C) dates for the Afanasyevo Culture of the Paleometal period. The previous “long” chronology of the culture was widely criticized and contradicted many archaeological observations. The exceedingly wide ranges of the liquid scintillation counting (LSC) dates from bone samples produced in several laboratories and the systematically older ages for the wood/charcoal samples finally reveal the shortcomings of the conventional “long” chronology. From accelerator mass spectrometry (AMS), the Afanasyevo burials of the Altai are dated to the 31st–29th century BC, whereas those of the Middle Yenisei Region to the 29th–25th century BC, which confirms the relatively earlier age of the Altai monuments. The “short” chronology removes the incompatibility of deriving the Afanasyevo Culture from the Yamnaya Culture, which previously appeared “younger” than the Afanasyevo, and also contradictions with the archaeological data. It also explains the small number of sites, the small size of the cemeteries and the lack of the internal periodization. We can now clearly move, from the earlier understanding that the Afanasyevo chronology is too broad, towards a different perception. The new AMS dates only represent a “core” for the Afanasyevo chronology, which cannot be narrowed down, but could be slightly expanded over time.

scholarly journals The Radiocarbon Content of Individual Lignin-Derived Phenols: Technique and Initial Results

Radiocarbon ◽  
2000 ◽  
Vol 42 (2) ◽  
pp. 219-227 ◽  
Author(s):  
A P McNichol ◽  
J R Ertel ◽  
T I Eglinton
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Phenolic Compounds ◽  
Accelerator Mass Spectrometry ◽  
Bulk Material ◽  
Polymeric Materials ◽  
Chemical Oxidation ◽  
Flavor Compounds ◽  
The Individual ◽  
Initial Results

We present a method for the isolation of phenolic compounds derived from lignin for radiocarbon analysis. These phenols are generated by chemical oxidation of polymeric materials and derivatized for separation and recovery by preparative capillary gas chromatography (PCGC). This technique yields tens of micrograms of pure, stable compounds that can be converted to graphite and analyzed by accelerator mass spectrometry (AMS). Analysis of model flavor compounds and dated woods indicates that, in most cases, the radiocarbon (14C) contents of the individual compounds, corrected for the contribution of the derivative, agree with that of the bulk material to within 20%.

scholarly journals Radiocarbon with Gas Chromatography

Radiocarbon ◽  
1995 ◽  
Vol 37 (2) ◽  
pp. 711-716 ◽  
Author(s):  
Christopher Bronk Ramsey ◽  
R. E. M. Hedges
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Pilot Study ◽  
Accelerator Mass Spectrometry ◽  
Ion Source ◽  
Tracer Studies ◽  
Chemical Fractions ◽  
Peak Sensitivity ◽  
Accelerator System

In 14C tracer studies, and when looking for modern contamination in archaeological samples, it is often necessary to measure the 14C concentration of individual chemical fractions. Gas chromatography (GC) is one method that is frequently used for separation of chemical fractions. The gas ion source at the Oxford Radiocarbon Accelerator Unit for accelerator mass spectrometry (AMS) provides the opportunity to measure fractions from a GC instrument directly. Although the first investigations are likely to be 14C tracer studies, such a GC-AMS system could find much wider application. We present results from a pilot study of the peak sensitivity, baseline stability and crosstalk of the accelerator system used in this way. We also discuss the practical considerations in developing a GC-AMS instrument for routine use.

scholarly journals List of Laboratories

Radiocarbon ◽  
2006 ◽  
Vol 48 (3) ◽  
pp. 493-517
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Complete List ◽  
Beta Counting

This is Radiocarbon's annual list of active radiocarbon laboratories and personnel known to us. Conventional beta-counting facilities are listed in Part I, and accelerator mass spectrometry (AMS) facilities are listed in Part II. Laboratory code designations, used to identify published dates, are given to the left of the listing. (See p 515 for a complete list of past and present lab codes.)

scholarly journals Critical Assessment of Analytical Methods for the Harmonized and Cost-Efficient Analysis of Microplastics

2020 ◽  
Vol 74 (9) ◽  
pp. 1012-1047 ◽  
Author(s):  
Sebastian Primpke ◽  
Silke H. Christiansen ◽  
Win Cowger ◽  
Hannah De Frond ◽  
Ashok Deshpande ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Analytical Techniques ◽  
Field Work ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Combined Application ◽  
Chromatography Mass Spectrometry ◽  
Recent Developments ◽  
Cost Efficient

Microplastics are of major concerns for society and is currently in the focus of legislators and administrations. A small number of measures to reduce or remove primary sources of microplastics to the environment are currently coming into effect. At the moment, they have not yet tackled important topics such as food safety. However, recent developments such as the 2018 bill in California are requesting the analysis of microplastics in drinking water by standardized operational protocols. Administrations and analytical labs are facing an emerging field of methods for sampling, extraction, and analysis of microplastics, which complicate the establishment of standardized operational protocols. In this review, the state of the currently applied identification and quantification tools for microplastics are evaluated providing a harmonized guideline for future standardized operational protocols to cover these types of bills. The main focus is on the naked eye detection, general optical microscopy, the application of dye staining, flow cytometry, Fourier transform infrared spectroscopy (FT-Ir) and microscopy, Raman spectroscopy and microscopy, thermal degradation by pyrolysis–gas chromatography–mass spectrometry (py-GC-MS) as well as thermo-extraction and desorption gas chromatography–mass spectrometry (TED-GC-MS). Additional techniques are highlighted as well as the combined application of the analytical techniques suggested. An outlook is given on the emerging aspect of nanoplastic analysis. In all cases, the methods were screened for limitations, field work abilities and, if possible, estimated costs and summarized into a recommendation for a workflow covering the demands of society, legislation, and administration in cost efficient but still detailed manner.

scholarly journals Towards a Radiocarbon Chronology of the Late-Glacial: Sample Selection Strategies

Radiocarbon ◽  
2001 ◽  
Vol 43 (2B) ◽  
pp. 1007-1019 ◽  
Author(s):  
M J C Walker ◽  
C Bryant ◽  
G R Coope ◽  
D D Harkness ◽  
J J Lowe ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Sample Selection ◽  
Late Glacial ◽  
Plant Macrofossils ◽  
Sampling Strategies ◽  
Radiocarbon Dates ◽  
Selection Strategies ◽  
Beta Counting ◽  
Radiocarbon Chronology

This paper outlines a dating program designed to test the reproducibility of radiocarbon dates on different materials of Late-Glacial age (plant macrofossils, fossil beetle remains, and the “humic” and “humin” chemical fractions of limnic sediments) using a combination of radiometric (beta counting) and accelerator mass spectrometry (AMS) techniques. The results have implications for the design of sampling strategies and for the development of improved dating protocols, both of which are important if a high-precision 14C chronology for the Late-Glacial is to be achieved.

Are Compact AMS Facilities a Competitive Alternative to Larger Tandem Accelerators?

Radiocarbon ◽  
2010 ◽  
Vol 52 (2) ◽  
pp. 319-330 ◽  
Author(s):  
M Suter ◽  
A M Müller ◽  
V Alfimov ◽  
M Christl ◽  
T Schulze-König ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
The Netherlands ◽  
High Voltage ◽  
Accelerator Mass Spectrometry ◽  
Biomedical Applications ◽  
Detection System ◽  
Ion Optics ◽  
Recent Developments ◽  
High Voltage Engineering

In the last decade, small and compact accelerator mass spectrometry (AMS) systems became available operating at terminal voltages of 1 MV and below. This new category of instruments has become competitive for radiocarbon detection to larger tandem accelerators and many of these instruments are successfully used for 14C dating or biomedical applications. The AMS group at ETH Zurich has demonstrated that small instruments can be built, which allow measurements also of other radionuclides such as 10Be, 26Al, 129I, and the actinides. 41Ca measurements can be performed with sufficient sensitivity for biomedical applications. A summary of recent developments made at the 500kV Pelletron in Zurich is given and its performance is compared with that of a commercial compact instrument from the company High Voltage Engineering Europe (HVEE) in Amersfoort, the Netherlands, operating at 1MV at CNA in Seville, Spain, as well as with that of larger AMS facilities. It turns out that the ion optics, stripper design, and the detection system are critical for the performance.

Measuring 14C Concentration in Wine to Monitor Global Distribution of 14C

Radiocarbon ◽  
2013 ◽  
Vol 55 (3) ◽  
pp. 1827-1833
Author(s):  
Hirohisa Sakurai ◽  
Saori Namai ◽  
Emiko Inui ◽  
Fuyuki Tokanai ◽  
Kazuhiro Kato ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Correlation Coefficient ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Accelerator Mass Spectrometry ◽  
Liquid Scintillation Counting ◽  
Liquid Scintillation ◽  
Fossil Fuel ◽  
Scintillation Counting ◽  
Northern And Southern Hemispheres

Using liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS), radiocarbon concentrations were measured for wine from 8 wineries located in 7 countries in the Northern and Southern hemispheres. The 14C concentrations of ethanol and residual materials in the wine were correlated (correlation coefficient 0.82). The δ14C measurements of wine samples from the mid-latitudes in the Northern Hemisphere were approximately 1l% lower than the extrapolations from Schauinsland data, suggesting a local fossil fuel effect. δ14C measurements from the wine samples from the Southern Hemisphere were higher than those from the Northern Hemisphere. The offsets of the 4 wine δ14C measurements were significant, with values between approximately 8% and 15%. Because the harvest years of the mixed grapes were estimated to be 7–12 yr older than their vintage years, this leads to a caveat when determining the 14C concentrations of the year using the wine vintage.

scholarly journals Progress in Radiocarbon Target Preparation at the Antares AMS Centre

Radiocarbon ◽  
2001 ◽  
Vol 43 (2A) ◽  
pp. 275-282 ◽  
Author(s):  
Q Hua ◽  
G E Jacobsen ◽  
U Zoppi ◽  
E M Lawson ◽  
A A Williams ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Sample Preparation ◽  
Accelerator Mass Spectrometry ◽  
Sample Pretreatment ◽  
Small Samples ◽  
Sample Processing ◽  
Target Preparation ◽  
Recent Developments ◽  
Technical Details ◽  
Fe Reduction

We present routine methods of target preparation for radiocarbon analysis at the ANTARES Accelerator Mass Spectrometry (AMS) Centre, as well as recent developments which have decreased our procedural blank level and improved our ability to process small samples containing less than 200 μg of carbon. Routine methods of 14C sample preparation include sample pretreatment, CO2 extraction (combustion, hydrolysis and water stripping) and conversion to graphite (graphitization). A new method of cleaning glassware and reagents used in sample processing, by baking them under a stream of oxygen, is described. The results show significant improvements in our procedural blanks. In addition, a new graphitization system dedicated to small samples, using H2/Fe reduction of CO2, has been commissioned. The technical details of this system, the graphite yield and the level of fractionation of the targets are discussed.

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