Yan Ma

Bio: Yan Ma is an academic researcher. The author has contributed to research in topics: Liquid scintillation counting & Scintillation. The author has an hindex of 4, co-authored 8 publications receiving 42 citations.

Method of Polonium Source Preparation Using Tellurium Microprecipitation for Alpha Spectrometry.

Abstract: A thin-layer source for the counting of polonium isotopes by alpha spectrometry can be rapidly prepared using microprecipitation with tellurium. Polonium was first coprecipitated with the reduction of tellurium by stannous chloride, followed by microfiltration onto a membrane filter for counting. This microprecipitation method is faster, cheaper, and more convenient than the traditional spontaneous deposition method, with an excellent Po recovery (>90%) under optimal conditions. The influences of several experimental parameters, including Te(IV) quantity, reaction time, and HCl molarity, were examined to determine the optimal conditions for Te microprecipitation. The decontamination factors of potential interferences from various radionuclides (Ra, Th, U, Pu, Am) for the counting of long-lived polonium isotopes (208Po, 209Po, and 210Po) were also evaluated, and the results confirmed a good selectivity on polonium by this microprecipitation method. Due to its strong resistance to high acidity up to 12 M HC...

Method for sequential determination of 55 Fe and 63 Ni in leaching solution from cement solidification

Abstract: A method for sequential determination of 55Fe and 63Ni in leaching solution of cement solidification using liquid scintillation counting (LSC) was developed. In this method, 55Fe and 63Ni were first precipitated in the form of hydroxide and subsequently purified by anion exchange chromatography and dimethylglyoxime precipitation. After the purification, 55Fe and 63Ni were determined by LSC. The performance of the method was examined, and minimum detectable activity concentration was determined to be 0.82 Bq L−1 for 55Fe and 0.42 Bq L−1 for 63Ni in leaching solution samples with a counting time of 1 h. High decontamination factors for 55Fe and 63Ni were also obtained.

Liquid scintillation counting for determination of radionuclides in environmental and nuclear application

Abstract: Liquid scintillation counting (LSC) is a major technique not only for measurement of pure beta emitting radionuclides, but also radionuclides decay by electron capture and alpha emission. Although it is a conventional radiometric technique, but still a competitive techniques for the measurement of many radionuclides. This paper summaries the major development of this measurement technique in instrumentation, methodology and applications in the past decades. The progresses in the instrumentation and methodology mainly focus on the commercialization of triple-to-double coincidence ratio based LSC techniques and its application in the determination of different radionuclides. An overall review and discussion on the LSC based analytical methods for the determination of major radionuclides in environmental researches, decommissioning of nuclear faculties and nuclear application are presented, in both measurement techniques and sample preparation using radiochemical separation. Meanwhile the problems and challenges in the development and application of the LSC are also discussed.

Rapid, versatile and sensitive method for the quantification of radium in environmental samples through cationic extraction and inductively coupled plasma mass spectrometry

Abstract: In this study, the method proposed by St-Amant et al. based on ionic chromatography was modified to rapidly quantify 226Ra and 228Ra by inorganic mass spectrometry in a broad variety of matrices at environmental levels. The sample volume loaded on the cationic resin AG50Wx8 was varied to achieve the highest possible adsorption without any significant loss of retention for radium. The pH and volume for the elution steps were optimized to obtain the highest pre-concentration factor and compatibility with plasma-based instruments and to eliminate interference to the maximum extent possible. Finally, inductively coupled plasma mass spectrometry (ICP-MS) instrumental conditions were investigated and optimized for the quantification of radium. An instrumental detection limit of 0.53 pg L−1 in 226Ra and 0.47 pg L−1 in 228Ra were achieved. When combined with the cationic separation procedure for interference removal, the overall method detection limit decreases to 10 fg L−1 in less than 2 hours.

Radioanalysis of ultra-low level radionuclides for environmental tracer studies and decommissioning of nuclear facilities

Abstract: Determination of long-lived radionuclides is critical for environmental radioactivity investigation, environmental processes studies and decommissioning of nuclear facilities. This paper summarizes main progress in the radiochemical analysis in our laboratories in the past years for determination of ultra-low level radionuclides in the environment using chemical separation combined with mass spectrometry measurement. The analytical methods for determination of ultra-low level 129I and its chemical species in various environmental samples are highlighted. The methods developed in our laboratories for characterization of decommissioning waste, especially the methods for the determination of difficult-to-measure radionuclides using sequentially chemical separation and radiometric measurement are also briefly presented. This is also a part of the Hevesy Medal award lecture in the RANC2019 conference.

210Po in the environment: insight into the naturally occurring polonium isotope

Abstract: Polonium is rapidly emerging as an international environmental health concern primarily because of the recent rise in hydraulic fracturing (fracking). Recovery of unconventional oil and gas generates produced water containing natural radioactivity, which is increasing the radiological impact of 210Po. In this context, accurate measurements of 210Po in environmental samples is crucial because 210Po is the main contributor to the natural radiation dose received by all living organisms. However, the analytical chemistry of polonium is complicated, primarily due to its volatility. This review highlights recent analytical progress and challenges in determination of 210Po in the environmental and biological samples.