• Applied Biological Chemistry
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• v.18 no.2
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• pp.56-60
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• 1975

A rapid method for the measurement of the absolute activity of carbon-14 in cotyledons and root of etiolated pea seedlings has been developed. Fresh tissue was frozen in liquid air, ground and suspended in gel phosphor and subjected to measurement for its radioactivity by liquid scintillation counter. Apparent activity of the suspended tissue sample calculated by counting efficiency value obtained by internal standardisation, was found to be related to absolute activity of the tissue, determined by flask combustion technique, by a constant factor. Once this factor is determined experimentally, analysis of C-14 lebelled tissue involves only fairly simple suspension counting by liquid scintillation counter. Present method appears to be applicable to other tissues tagged with C-14.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.3
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• pp.180-187
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• 1999

Radiocarbon dating method using benzene liquid scintillation was performed on the oyster shell fragments which producted from the shell mounts at Hadong Mogdori in Kyeongsangnamdo. This paper described to the age dating method and compared to the result. The carbon in sample is synthesized to a benzene through the sample preparation, $SrCO_3$, $SrC_2$, $C_2H_2$ and $C_6H_6$ synthesizing process. Age dating is calculated by Wallac 1415 Liquid Scintillation Counter. The result of age dating is estimated to be $4905{\pm}112$ yr BP in Yosu Univ. which is a good agreement with the result in Shimane Univ. ($4912{\pm}123$ yr BP). Radiocarbon dating method using benzene liquid scintillation is a simple and economical in operation and establishment, it has a potential instrumentation in the university and research institute.

• Journal of the Korean Society of Radiology
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• v.13 no.6
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• pp.847-856
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• 2019

The various environmental issues arose with the development of today's economy. naturally, people were increased interest in environment and the importance of research on drinking water and contamination are emerging especially. A number of country areas, uranium and ²²²Rn in ground water have been detected to people using as drinking water. So this study evaluated the way for more accurate measurements than when measuring ²²²Rn concentrations in the ground water containing. the experiment was performed using the low-level liquid scintillation counter with an alpha, beta analysis easy PSA function of pulse. the scintillator as the preparation of the ground water samples are mixed, the measure value detection is lowered over prepare period and expiration date. Energy spectrum was also moved to a lower side channel. As a long time to buy the scintillator and over time after opening, it was confirmed that detection is lowered. if the purpose is to use a different scintillator can see the energy through the channel change.

• Analytical Science and Technology
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• v.20 no.5
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• pp.419-423
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• 2007

Environmental low level tritium analysis was studied using liquid scintillation counter(LSC) and electrolytic enrichment method. To obtain low level blank count, various counting vials were investigated. Among them, teflon coated PE vial had a lower blank count rate (1.86 cpm) and we obtained 2.01 Bq/L detection and tritium separation factor was above 20. LSC counting efficiency obtained $28.70{\pm}0.27%$ using the NIST tritium standard water sample.

• Analytical Science and Technology
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• v.29 no.2
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• pp.65-72
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• 2016

This study presented an analytical method for detecting radium in soils using a liquid scintillation counter (LSC). The isotope ²²⁶Ra was extracted from soil using the fusion method and then separated from interfering radionuclides using the precipitation method. Radium was coprecipitated as sulfate salts with barium (Ba) and then converted into Ba(Ra)CO₃, which is soluble in an acidic solution. The isotope ²²²Rn, the decay progeny of ²²⁶Ra, was trapped in a water immiscible cocktail and analyzed by LSC. The pulse shape analysis (PSA) level was estimated using ⁹⁰Sr and ²²⁶Ra standard solutions. The figure of merit was the highest at PSA 80, while the alpha spillover was the lowest at PSA 80. The counting efficiency was 243 ± 2% in a glass vial. This analytical method was verified with International Atomic Energy Agency (IAEA) reference materials, including IAEA-312, IAEA-314, and IAEA-315. The recovery ranged from 60–82%, while the relative bias between the measured value and the recommended value was less than 10%. The minimum detectable activity was 2.1 Bq kg⁻¹ with dry mass 1 g, the background count rate of 0.02 cpm, the recovery rate of 70% and counting time of 30 min.

• Analytical Science and Technology
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• v.12 no.5
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• pp.428-435
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• 1999

A method for measuring Rn-222 and Ra-226 in aqueous sample using liquid scintillation counting technique has been studied. The Rn-222 was extracted easily from the water sample (10 mL) by 12 mL of xylene based organic scintillant. After radioactive equilibrium between Rn-222 and its alpha emitting decay products for three hours, the alpha activity from Rn-222 and its decay products were measured in a scintillation vial using the Wallae $1220^{TM}$ Quantulus liquid scintillation counter. Ra-226 concentration in aqueous sample was determined, after isolation of Ra-226 from the sample matrix, by extraction the ingrowth of the Rn-222 and its alpha emitting decay products with xylene based organic scintillant. The optimum pulse-shape analysis (PSA) value was evaluated by the figure of merit (FM) criterion. Minimum detectable activity (MDA) is about 0.14 Bq/L (3.78 pCi) for the region of Rn-222 and its alpha emitting decay products and 0.06 Bq/L (1.63 pCi) for the region of Po-214 respectively, with 200 min, counting time at PSA level 100 in the low-diffusion polyethylene vial and xylene based cocktail solution. Experiment on the optimum sample-cocktail volume ratio, the influence of agitation and the diffusion of radon from vial were carried out.

• Nuclear Engineering and Technology
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• v.53 no.11
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• pp.3798-3807
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• 2021

Tritium extraction from radioactively contaminated cement mortar samples was performed using heating and liquid scintillation counting methods. Tritiated water molecules (HTO) can be present in contaminated water along with water molecules (H₂O). Water is one of the primary constituents of cement mortar dough. Therefore, if tritium is present in cement mortar, the buildings and structures using this cement mortar would be contaminated by tritium. The radioactivity level of the materials in the environment exposed to tritium contamination should be determined for their disposal in accordance with the criteria of low-level radioactive waste disposal facility. For our experiments, the cement mortar samples were heated at different temperature conditions using a high-temperature combustion furnace, and the extracted tritium was collected into a 0.1 M nitric acid solution, which was then mixed with a liquid scintillator to be analyzed in a liquid scintillation counter (LSC). The tritium extraction rate from the cement mortar sample was calculated to be 90.91% and 98.54% corresponding to 9 h of heating at temperatures of 200 ℃ and 400 ℃, respectively. The tritium extraction rate was close to 100% at 400 ℃, although the bulk of cement mortar sample was contaminated by tritium.

• Analytical Science and Technology
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• v.5 no.4
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• pp.381-387
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• 1992

Optimum counting condition of a low level liquid scintillation counter for radiocarbon dating has been determined to minimize the contribution of tritium activity and get the highest FOM by the variation of scintillation solutions, scintillation solution to benzene ratio, and ${\beta}$-ray spectrum counting ranges. Under the condition, background count rate has been reduced to $2.26{\pm}0.03cpm$, and the maximum measurable age reached to about 40,000 years. And the practicality of counting system has been verified by the analysis of shell and peat samples.

• Analytical Science and Technology
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• v.25 no.2
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• pp.146-151
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• 2012

An analytical method was developed for the measurement of uranium isotope in ground water using the liquid scintillation counting technique. A LKB Wallac Quantulus 1220 liquid scintillation counter (LSC) equipped with pulse shape analyzer (PSA) and a solvent extraction method were used for the measurement of uranium isotope in ground water samples. The effect of solution volume on the extraction efficiency was evaluated for 100 to 1000 mL solutions using a NIST standard reference material (NIST SRM 4321C). The effect of groundwater pH on the extraction efficiency was also investigated for pH ranging from 0.5 to 10. It was found that the extraction efficiency had a strong dependence on pH showing a maximum at pH 2. In contrast, the effect of groundwater volume on the extraction efficiency was negligible in the range investigated. According to the method, the extraction efficiency of uranium isotopes was near 96% and the lower detection limit for uranium was 0.018 Bq/L with the counting time of 300 min. The result of this study was also verified by the conventional ICP-MS measurement. It is demonstrated that the suggested method is valuable to the determination of the optimum extraction and measurement conditions for uranium in ground water. The method was successfully applied to the ground water at four locations near the Daejeon province. It was found that the uranium content and the isotopic ratio of $^{234}U/^{238}U$ at the locations ranged 0.59~6.69 Bq/L and 0.72~1.40, respectively.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.10a
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• pp.330-330
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• 1998