The effect of impurities on calculated activity in the triple-to-double coincidence ratio liquid scintillation method

2012 ◽  
Vol 70 (9) ◽  
pp. 2170-2175 ◽  
Author(s):  
Denis E. Bergeron ◽  
Ryan P. Fitzgerald ◽  
Brian E. Zimmerman ◽  
Jeffrey T. Cessna
Radiocarbon ◽  
2019 ◽  
Vol 61 (6) ◽  
pp. 1973-1981
Author(s):  
C Telloli ◽  
A Rizzo ◽  
C Canducci ◽  
P Bartolomei

ABSTRACTThe ENEA Radiocarbon Laboratory (Bologna, Italy) has been operating since 1985; it is the oldest among such laboratories operating in Italy and has been active for about 30 years in the field of dating of different types of samples with the radiocarbon (14C) liquid scintillation method. This study shows the detailed procedure for radiocarbon analysis on bioplastic materials by means of the synthesis of benzene, which includes CO2 production and purification, synthesis of acetylene, and synthesis and collection of benzene. The changes made to the original design of the synthesis procedures and the operational parameters adopted to optimize the combustion of the plastic materials are described. The measurement of 14C activity was performed using the liquid scintillation counting technique by a QuantulusTM 1220 low-background counter. The δ13C content was compared with the percentage of 14C concentration for the characterization of the bio content in plastic used in the food packaging.


Radiocarbon ◽  
2012 ◽  
Vol 54 (3-4) ◽  
pp. 305-318 ◽  
Author(s):  
Michel Wuttmann ◽  
François Briois ◽  
Béatrix Midant-Reynes ◽  
Tiphaine Dachy

The Neolithic site KS043, excavated by the Institut français d'archéologie orientale (IFAO), is situated in the southern basin of the Kharga Oasis (Egypt). It is one of the very few stratified prehistoric sites of the eastern Sahara. The archaeological remains were found near artesian springs that provided water for pastoralists during the dry Middle Holocene. In situ settlement features provided well-preserved material (charcoal, ashy sediment, ostrich eggshell) sufficient to perform radiocarbon dating in the IFAO laboratory in Cairo by the conventional liquid scintillation method. In 2 cases, ostrich eggshell and charcoal within the same in situ context gave significantly different results of, respectively, ∼600 and ∼1200 yr younger dates for the ostrich eggshells. The strong discrepancy is here highlighted for the first time and we suggest that it may be linked with postdepositional phenomena in the vicinity of the artesian springs. A thorough review of 14C dates available for the Holocene in eastern Sahara shows that ostrich eggshells have been widely used. They seem slightly more prone to be discarded than other material but were never the object of a particular study in this context. Bayesian modeling shows that the Neolithic occupation at site KS043 spans a range from 5000 to 3950 cal BC (and concentrated around 4600–4350 cal BC). Characteristic flint tools and pottery relate this occupation to the end of the Neolithic and show links with the Tasian culture, confirming the timing of the presence of this cultural complex in the desert before its appearance in the Nile Valley.


Radiocarbon ◽  
1993 ◽  
Vol 35 (3) ◽  
pp. 393-398 ◽  
Author(s):  
Kh. A. Arslanov ◽  
T. V. Tertychnaya ◽  
S. B. Chernov

The important problem of contamination of old samples by younger 14C necessitates treatment of organic and carbonate samples to ensure more complete removal of contaminating carbon. Here we present studies of chemical procedures for the liquid scintillation method of 14C dating undertaken since 1960 in the former USSR. We discuss new procedures such as lithium carbide synthesis from charred organic samples and benzene synthesis on a V2O5·Al2O3·SiO2 catalyst, as well as memory effect in the carbide synthesis procedure and characteristics of two homemade counters.


1987 ◽  
Vol 116 (2) ◽  
pp. 285-289 ◽  
Author(s):  
M. Abuzeida ◽  
B. H. Arebi ◽  
Y. A. Zolatarev ◽  
N. A. Komarov

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