Determination of Arsenic and Mercury in Various Environmental Matrices by Chemical Neutron Activation Analysis

Chemical neutron activation analysis was developed for determining trace amounts of arsenic and mercury in a variety of environmental matrices, including water, sediment, rock, plants, animal organs, etc: The adsorption procedure via magnesium oxide as the agent was applied to preconcentrate arsenic from the digested environmental matrices where arsenic in the form of As(V) ion could be highly efficiently adsorbed by hydrous magnesium oxide. On the other hand, the extraction procedure via lead diethyldithiocarbamate as the agent was applied to preconcentrate mercury from the digested environmental matrices where mercury in the form of Hg(II) ion could be highly efficiently extracted into the solution of lead diethyldithiocarbamte in dichloromethane. Both of the preconcentrated materials prepared ultimately in the solid states, i.e., arsenic in magnesium oxide and mercury in lead diethyldithiocarbamte were taken to be neutron irradiated. The γ spectra of the preconcentrated samples irradiated generally showed clear peaks of the product radionuclides from arsenic or from mercury by the different separation procedures. The possible interfering elements such as Na, Br, etc., were prominently minimized in respect of most of the preconcentrated samples. The reliability and accuracy of the proposed analytical methods for detecting arsenic and mercury can be confirmed by the assay of commercial standard reference materials including sediment, rock, plants, and animal organs.     

一种新的测定铱丰度及其化学形态的放射化学中子活化分析法

本工作建立了一个以长链伯胺N_(1923)萃取为基础的放射化学中子活化分析法,可测定含量低达10~(-12)g/g的Ir。影响Ir萃取率的关键是Ir在水溶液中的化学形态,而不是其价态。此外,我们发展了一个用于地质样品物相分离的化学分相方法,研究了白垩系-第三系界线粘土样品中异常Ir的赋存状态。     

Determination of Traces of Uranium and Thorium in Environmental Matrices by Neutron Activation Analysis

Radioactive elements like ²³²Th and ²³⁸U along with their daughter products, form part of all environmental matrices and are getting transferred to living beings by different pathways, leading to a continuous radiation exposure and need to be monitored. This paper presents an analytical methodology, highlighting the need to separate interfering beta- and gamma-emitters from the analytes, when neutron activation analysis is employed for the determination of traces of uranium and thorium in soil and plant materials. The method has been applied to the soil and plant materials from selected regions of India, along with standard reference materials to verify the validity of the proposed separation scheme. The overall reproducibility of the procedure was 2–10%. The concentration values of uranium and thorium so obtained, have been used to calculate transfer factors from soil to various parts of wheat plant.     

Instrumental Neutron Activation Analysis for Certification of Ion-Implanted Arsenic in Silicon

Standard reference material (SRM) 2134 Arsenic Implant in Silicon was produced at the National Institute of Standards and Technology (NIST) as a calibrant for secondary ion mass spectrometry. Instrumental neutron activation analysis was used as a primary method for certification of the arsenic implanted dose. A complete evaluation of all sources of uncertainty yielded an expanded relative uncertainty for the mean value of this SRM to be 0.38% at approximately the 95% level of confidence. No evidence indicating significant heterogeneity among samples was observed.     

茂县大骨节病病区水化学特征

茂县大骨节病区分布具有明显的地域特点,考察了当地地质环境概况,同时对该区地表水、地下水取样,对常量组分、腐殖酸、微量组分进行了分析,阐述了该区的水化学特征。     

The Determination by Neutron Activation Analysis of Selected Elements in Cigarettes

Abstract

Neutron activation analysis was used for the determination of Na, Al, CI, K, Ca, Sc, Mn, Cu, Br, and La in the tobacco, mainstream smoke condensate, paper, and dropped ash of the Kentucky Reference Cigarette (IRI). The procedure requires no sample transfers prior to activation and no radiochemical separations before counting.     

Nondestructive Determination of Mercury in Copper by Thermal Neutron Activation Analysis

Abstract

Thermal neutron activation analysis was applied to the nondestructive determination of parts per billion (p.p.b.) quantities of mercury in high purity, oxygen-free high conductivity (OFHC) copper. The data were treated to a five-point gamma spectrum smoothing to reduce the statistical variations due to the low count rates. Linear regression and a statistical evaluation of the data were also performed. Net photopeak counting rates of approximately 43 counts per minute (c.p.m.), compared to a background of approximately 6 c.p.m., were obtained for six two-gram copper samples containing 38 ± 12 p.p.b. mercury.     

中子活化分析测定油菜叶绿体中的微量元素

１　　引　　　　言微量元素如锰、铁和铜在植物光合作用中起重要作用,其在叶绿体中的含量与赋存状态已被广泛研究,但对叶绿体中其它微量元素的含量及对光合作用的影响研究较少。近年来,大量实验证明稀土元素能提高植物光合作用的能力,但叶绿体中是否含有稀土元素还不清楚。本工作分离并纯化了油菜的叶绿体,用中子活化分析测定了包括８个稀土元素在内的１９种微量元素的含量。２　　实验部分２．１　　仪器与试剂　　ＤＬ－７Ａ冷冻离心机（中国科学院武汉科学仪器厂）,７２１分光光度计（上海精密科学仪器有限公司）,高纯锗探测器及…     

Determination of platinum distribution in adenocarcinoma black-mice by Neutron Activation Analysis

30 female C57 bl. mice were treated with Adenocarcinoma im. in the right hind leg. Three days later cis-dichlorodiamine platinum was applied orally /15 mg/kg/ to all animals and additional 0.05 mg Prednisolone i.p. to 20 animals. Tissue samples from bloods, livers, kidneys, spleens, hearts, lungs, tumors and gastrointestinal tract were analyzed for their Pt concentration after therapy with cis-dichlorodiammine platinum complexes and Prednisolone by instrumental neutron activation analysis. Even 5 animals were sacrified. The amount of Pt in most of the organs examined remained under 0.05% of the quantity applied. Maximum values were detected at the end of the experiment, except for the gastrointestinal tract, the liver and the kidneys. Treatment of the animals with Prednisolone did not produce a significant different distribution of Pt. Only in tumor tissues a significantly higher amount of Pt was observed after Prednisolone treatment at 48 h but not at 72 h. Blood levels increased with time after Prednisolone treatment, without Prednisolone blood levels decreased.     

Determination of Trace Molybdenum in Biological Matrices by Neutron Activation Analysis

Based on consecutive extractions using bismuth diethyldithiocarbamate and thallium diethyldithiocarbamate as reagents, molybdenum was selectively and highly enriched from biological matrices, and then subjected to neutron activation analysis. Most of interfering elements, e.g., Na, K, Br, P, Fe, U, etc. were simultaneouly removed and the preconcentrated samples always showed only the r rays from molybdenum after neutron bombardment. Thus, molybdenum in the biological matrices could be accurately determined.     

Determination of Heavy Metals as Environmental Pollutants: Use of Instrumental Neutron Activation Analysis

The simultaneous determination of heavy metals by instrumental neutron activation analysis (INAA) in some environmental samples have been considered. A new approach has been proposed to assess the potentialities and the most adequate use of INAA for each particular heavy metal.     

Epithermal/Fast Neutron Cyclic Activation Analysis for the Determination of Fluorine in Environmental and Industrial Materials

Pseudocyclic activation analysis (12-second irradiation, 12-second count, 5 cycles, 25 minutes between cycles) is used to determine fluorine in plastic and rubber with detection limits in the range 15–40 mg/kg. The detection of fluorine in materials containing high concentrations of aluminum is improved using the ¹⁹F(n,p)¹⁹O reaction, induced by fast neutrons, (30-second irradiation, 30-second count, 25-minute decay between cycles). The method was applied to a biomonitoring survey in the vicinity of an aluminum smelter in the Årdal region, Norway. The fluorine concentration in the moss and soil samples could be determined in all samples above the detection limits of 50 and 100 mg/kg, respectively.     

Determination of Trace Elements in Liquid Fuels by Instrumental Neutron Activation Analysis

Abstract

An instrumental neutron activation analysis with Ge(Li) γ -spectrometry and computer-assisted data reduction, has been developed for the determination of more than 20 elements in different liquid fuels. Organo-metallic standard solutions were mixed to obtain suitable standards. Two neutron irradiations and 4 γ-spectrometric measurements are required for each sample. Corrections were taken into account for a few spectrometric and nuclear interferences. The overall standard deviation for nearly all elements is mainly determined by counting statistics. The following elements can be determined : Na, Al, S, Cl, K, Sc, V, Cr, Fe, Co, Ni, Cu, Zn, As, Se, Br and La whereas the concentration of the following elements are mostly near the limit of detection: Mg, Mo, Sb, Ba, Th and Hg.     

Determination of Trace Elements in Tea and Coffee by Neutron Activation Analysis

Thermal neutron activation analysis, a high-resolution Ge(Li) gamma-ray spectrometer, and an IBM 360/67 digital computer were used to determine the concentration of Na, K, Sc, Cr, Mn, Fe, Co, Cu, Zn, Se, Br, Rb, Sb, Cs, and Hg in ground coffee and tea. This nondestructive multielement technique requires neither pre- nor postirradiation chemistry and eliminates problems of reagent contamination. The method is simple, precise and sensitive to 15 elements. Interferences from fast neutron (n, p) and (n, α) reactions are small and, if necessary, corrections may be applied easily. This technique can be applied to percolated tea and coffee.     

南极岩石样品中稀土元素的中子活化分析

用仪器中子活化分析技术,测定了南极岩石中8种稀土元素含量,讨论了不同岩石的稀土模式特点。     

The Determination of Co in Plant Materials by Radiochemical Neutron Activation Analysis

The influence of irradiation conditions on the results of Co determination in plant samples by radiochemical neutron activation analysis (RNAA), after the conventional and microwave assisted wet digestion, has been investigated. Nine CRMs of botanical origin were examined. The study has demonstrated that the effectiveness of mineralization depended significantly on the kind of sample and the irradiation conditions. When analyzed CRMs were subjected to long-term irradiation in a high neutron flux, the mineralization using the microwave technique was necessary to obtain the correct results of Co determination in some of the plant samples. It has been proved that microwave digestion in a mixture of HNO₃+H₂O₂+HF should be a standard method of wet ashing, independent on matrix and irradiation conditions.     

碳棒涂膜电极流动注射法测定环境水样中的阴离子表面活性剂

采用自制碳棒PVC涂膜阴离子表面活性剂电极 ,建立了测定环境水样中阴离子表面活性剂的流动注射电位分析新方法。电极膜最佳组成 :THDA DBS 5mg ,DBS 0 .4mL,NB 0 .3mL ,PVC粉 0 .2g;电极线性响应范围 1× 1 0 - 3～ 1× 1 0 - 6 mol L。以 0 .0 1mol LKCl溶液作载流 ,流速 6.6mL min ,进样体积 2 0 0 μL,分散管长 2 0cm ,采样频率 5 0～ 80次样 h。测定 1 0 - 3、1 0 - 4 mol LDBS溶液 ,RSD≤ 3 .1 2 % (n=7) ,回收率 88.0 %～ 1 0 5 .0 %。电极易制作 ,成本低 ,FIA流路简单 ,操作方便 ,且克服了直接电位法电位飘移大的缺点 ,有较好的实用性     

Determination of Trace Amount of Mercury in Human Hair by Neutron Activation Analysis

Trace amount of mercury in human hair has been determined by destructive neutron activation analysis. It was found that the contents of mercury in the hair of normal people in Taiwan area is the order of 6 ppm. It is of interest to point out that very little fluctuation is observed in the contents of mercury in human hair regardless of sex and age of the normal people under investigation. On the other hand for those people who are working in the caustic soda manufacturing plant in which mercury is used as cathode in the electrolysis process of saline water, the mercury contents in their hair are definitely much higher (ca. 30 times) than the average values of normal people.     

An Internal-Standard Method for Determination of Trace Impurities in Semiconductor Grade Silicon by Neutron Activation Analysis

An internal-standard method^1–4) has been applied for the determination of La, Sb, Au, Cr and Ag in silicon single-crystal by neutron activation analysis using cobalt as an internal-standard element. No chemical separation is required in this case and the precision obtained with the present method is satisfactory.     

人体子宫癌活组织中微量元素的中子活化分析

本文利用样品的低温干燥预处理技术和仪器中子活化分析方法,同时测定了人体子宫癌活组织中的29种微量元素,并分别与宫颈炎组织和正常组织比较,初步研究结果表明,子宫癌组织,宫颈炎组织和正常组织中Au,I,Se等微量元素有显著差异。