Some Possibilities for the Development of 14C Measurements by Liquid Scintillation Counting

The possibilities of widening the ranges of usage of scintillation counters are studied. As a result of the introduction of the active guard, the background in 14C channel reduces 30 to 75 percent and the stability of background increases. The application of quartz vials and a plastic scintillator as an active guard establishes 14C activity in small amounts of scintillation cocktail (up to 0.1g C) and dates samples with older ages (up to 57,000 years). The parameters of devices are given in case of different amounts of scintillation cocktail.

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Optimization of Liquid Scintillation Counting for 14C Dating

Radiocarbon ◽

10.1017/s0033822200007785 ◽

1986 ◽

Vol 28 (2A) ◽

pp. 597-602 ◽

Cited By ~ 1

Author(s):

Fernando E Angiolini ◽

Miguel C Albero

Keyword(s):

Liquid Scintillation Counting ◽

Figure Of Merit ◽

Liquid Scintillation ◽

Aluminum Foil ◽

Counting Efficiency ◽

Scintillation Counting ◽

14C Dating ◽

Scintillation Cocktail ◽

Standard Spectrum ◽

Pure Benzene

The effects of different measurement conditions and sample preparation in liquid scintillation counting of benzene for 14C dating were tested. The goal of this work was to find the highest figure of merit through the variation of scintillation cocktail to benzene ratio, and measurement windows. Measurements were performed on 5ml of benzene plus increasing quantities of scintillation cocktail (7g of PPO and 0.5g of Me2POPOP in 1L of scintillation-grade toluene). Spectra of both background and standard were obtained and the counting windows selected for the highest figure of merit (Q). The best condition was 5ml of benzene plus 0.75ml of scintillation cocktail. This spectrum is compared with that of 1) pure toluene-14C plus cocktail, and 2) pure benzene-14C in which the equivalent amount of PPO and Me2POPOP present in 0.75ml of cocktail was dissolved. A correlation between the increase of the amount of cocktail and the broadening of the spectrum was observed. The effect of wrapping the upper part of the counting vial with aluminum foil to reduce background was also tested. A drastic background increment was observed in the low energy range, for unwrapped vials; the standard spectrum showed a broadening and a lower counting efficiency which reduced the figure of merit.

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Radium interference during radon measurements in water: comparison of one- and two-phase liquid scintillation counting

Archives of Industrial Hygiene and Toxicology ◽

10.2478/aiht-2021-72-3480 ◽

2021 ◽

Vol 72 (3) ◽

pp. 205-215

Author(s):

Ivana Stojković ◽

Nataša Todorović ◽

Jovana Nikolov

Keyword(s):

Liquid Scintillation Counting ◽

Liquid Scintillation ◽

Scintillation Counting ◽

Limited Capacity ◽

Two Phase ◽

Phase Liquid ◽

The Stability ◽

Radon Measurements ◽

Measurement Efficiency ◽

Insight Into

Abstract Assessment of radiation exposure to drinking, surface, and groundwater and of the associated health risks calls for accurate and precise 226Ra and 222Rn measurements. One method that fits the bill is liquid scintillation counting (LSC), which allows measurements in one-phase (homogenous) or two-phase samples. The aim of our study was to compare the measurement efficiency with both variations in Niška Banja spa water, known for its elevated 222Rn content to get a better insight into the stability and behaviour of the samples and 226Ra interference in samples spiked with 226Ra with 222Rn measurement. 226Ra interference was more evident in homogenous, one-phase and much lower in two-phase samples. However, one-phase samples offer more accurate indirect 226Ra measurements. Water-immiscible cocktails (in two-phase samples) have shown a limited capacity for receiving 222Rn generated by Ra decay from the aqueous to organic phase when 222Rn/226Ra equilibrium is reached. We have also learned that samples with naturally high 222Rn content should not be spiked with 226Ra activities higher than the ones found in native samples and that calibration of two-phase samples can be rather challenging if measurements span over longer time. Further research would require much lower 226Ra activities for spiking to provide more practical answers to questions arising from the demonstrated phenomena.

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Carbon-14 Assay After Parr Peroxide Bomb Fusion

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/53.1.86 ◽

1970 ◽

Vol 53 (1) ◽

pp. 86-88

Author(s):

Leonard A. Ford

Keyword(s):

Carbon Dioxide ◽

Sodium Carbonate ◽

Liquid Scintillation Counting ◽

Liquid Scintillation ◽

Scintillation Counting ◽

Organic Base ◽

Scintillation Cocktail ◽

Carbon 14 ◽

Liquid Scintillation Cocktail ◽

Fused Salt

Abstract A method has been developed for converting organic 14C compounds to 14C carbon dioxide and subsequent quantitation by liquid scintillation counting. The sample is converted to sodium carbonate in a Parr bomb. Carbon dioxide is liberated from the fused salt, absorbed in an organic base, and incorporated in a liquid scintillation “cocktail” for radioassay. Some advantages over existing methods in current use are given.

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