电感耦合等离子体原子发射光谱(ICP-AES)法测定金属铬中Fe、Al、Si

采用盐酸溶样,标准加入法消除基体铬的干扰,利用电感耦合等离子体原子发射光谱(ICPAES)法测定金属铬中Fe、Al、Si。对仪器参数以及被测元素的谱线选择进行了讨论,在选定最佳条件下,对标准样品金属铬进行测定,探讨了检测方法中标准曲线线性相关性、检出限、精密度及加标回收率等指标,发现各元素的测定值与认定值基本一致,测量相对标准偏差均小于1%(n=7),加标回收率在96.9%~101%。方法实用性强,已经成功应用于金属铬中杂质元素的检测。     

Al behavior in tobacco cells by NAA and staining method

In the study of aluminum toxicity for plant, it is important to analyzethe behavior of Al in cells. We present how Al is taken up by tobacco cellsthrough lumogallion staining method developed by our laboratory. The fluorescenceintensity from the cell was increased rapidly between 4 and 8 hours of 1 mMAl treatment. To calibrate the fluorescence intensity from Al-lumogallioncomplex, Al amount in the cell was determined by NAA. When the same samplewas analyzed by ICP-AES, Al amounts in all the samples were 13% lower thanthose measured by NAA.     

Determination of Impurities in Gallium Oxide by NAA

Neutron activation analysis has been applied to determine 12 elements, viz. Na, Mn, As, Fe, Co, Zn, Se, Sc, Cr, Sb, Hf and Ta in high-purity Ga₂O₃. The first 7 elements could be determined by anion exchange separation and isopropyl ether extraction, and the last 8 elements by instrumental method. It is recommended that the first 3 elements are determine by one of the radiochemical modes and the others by the instrumental method.     

ICP-AES法测定锌锅中铝硅铬铁铅

随着汽车行业生产工艺的不断进步 ,对于其生产用料热镀锌板的质量要求也越来越严格 ,这就使对热镀锌锌锅中的杂质元素铝、硅、铬、铁、铅的测定也越来越重视。对于这些杂质元素的分析 ,目前主要有原子吸收光谱法和吸光光度法。近几年来 ,用ＩＣＰ ＡＥＳ法进行有关分析的报道也越来越多[1,2 ] 。本文在比较了不同的雾化器和不同的观测方式后 ,选择了用旋流雾化器加水平炬管的ＩＣＰ ＡＥＳ法 ,对铝、硅、铬、铁、铅进行同时、快速、准确的测定 ,得到了满意的结果。1　试验部分1.1　主要仪器与试剂岛津ＩＣＰＳ 75 0 0扫描式等离子体光谱仪铝…     

Determination of trace impurities in gallium arsenide by NAA

GaAs is not an ideal matrix for INAA because elements yielding activation products with half-lives up to about 5 d cannot be measured due to the interference by⁷²Ga and⁷⁶As (t_1/2=14.1 h and 26.4 h, respectively). The measurement of radionuclides with longer half-lives is interfered with by⁷⁴As (t_1/2=17.7 d), generated by fast neutrons. However, using an irradiation facility with a very low flux of fast neutrons, in which the generation of⁷⁴As is minimal, five elements could be determined in GaAs (Cr, Co, Zn, Ag, and Hg). For 27 elements the detection limits were below 1 g/g and for ten of them below 10 ng/g. The determination of nitrogen in GaAs has been carried out using the (n, p)-reaction on¹⁴N, which is induced by thermal neutrons. The activation product,¹⁴C, can be effectively separated and purified via¹⁴CO₂ and counted with high efficiency in a liquid scintillation counter, and nitrogen can be determined with fairly low detection limits if sufficiently high neutron fluxes and long irradiation times are applied. The procedure described is based on a reactor irradiation with a thermal flux of 2·10¹⁴ n·cm^–2·s^–1 for 51 days. 0.16±0.09 g/g N in GaAs were determined and the detection limit was about 3 ng/g.     

Determination of mercury and selenium in consumed food items in Libya using instrumental and radiochemical NAA

Summary Instrumental and radiochemical neutron activation analysis (INAA and RNAA, respectively) were used to analyze several consumed food items in Libya for the detection of low level concentrations of mercury and selenium. Selenium was determined using both short- and long-term irradiation, while mercury was determined in the long-term irradiation mode. At RNAA, after wet-ashing of samples in a microwave digestion unit, mercury was extracted with Ni(DDC)₃/CHCl₃, and selenium was precipitated in elemental form with ascorbic acid. For quality control, NIST reference materials were analyzed using the same procedures as for the food samples. The results of the analytical modes used were compared.     

人发中20种痕量元素的中子活化分析

探讨了用反应堆中子活化分析（NAA）同时测定人发中20种痕量元素的方法，其中包括部分测试难度较大的镧系、锕系元素；方法的检出限为10^-6～10^-14g，相对标准偏差（RSD，n=11）＜10％，选用美国国家标准局推荐的标准物质（NBS－SRN）进行对照，取得了满意的结果。     

Determination of inorganic elements in iliac crests of rabbits by NAA

This paper deals with the osteoporosis model of New Zealand rabbits in order to study the function of inorganic elements for women patients with osteoporosis. The thirty cases of iliac crest are collected and determined using neutron activation analysis (NAA). The results show that the fluorine concentrations in the experimental group are higher than those in control group and the magnesium concentrations are significantly lower (P<0.001), but the concentrations of K, Na, Ca, Ba, Mn, Sr show no remarkable difference. Combined with the serum biochemical markers of bone formation and resorption, the physiological functions of some metal elements in bone are also discussed.     

支持向量回归—铬天青S分光光度法同时测定Fe~(3+)和Al~(3+)

在溴化十六烷基三甲胺(CTMAB)和丙酮存在的条件下,于波长500~750 nm范围内,测定Fe3 、Al3 和铬天青S(CAS)显色体系的吸光度,用连续小波变换(CWT)对光谱数据进行预处理,再用支持向量回归(SVR)建模,建立了连续小波变换-支持向量回归方法(CWT-SVR)。方法用于模拟水样中Fe3 和Al3 的同时测定,结果满意。     

Determination of silicon in high purity metals by radiochemical NAA and CPAA

The indicator radionuclide³¹Si produced in neutron and deuteron activation analysis for silicon via the reactions³⁰Si(n,) and³⁰Si(d,p), respectively, is specifically separated from the irradiated sample by distillation as³¹SiF₄. In the case of aluminium, the distillation is carried out from a HF(HNO₃)H₂O₂ medium and in the case of molybdenum, niobium, tantalum, titanium and vanadium from a HF/HNO₃/HBr/H₂SO₄ medium. Using liquid scintillation counting, the achievable detection limits for neutron activation analysis are, depending on the type of the matrix, between 4–50 ng/g, and for the deuteron activation analysis of tantalum the detection limit is 5 ng/g.     

Determination and speciation of minor and trace elements in volcanic exhalations by NAA

Volcanic gases in the temperature range from 269° to 635° were sampled by means of a filter combination, consisting of two activated charcoal filters, a cooler and a condensate trap. Samples of the steam plume were taken additionally to quantify the depletion of the elements after condensation and dilution by the atmosphere. The elements F, Cl, Br, I, As, Sb, Se, Te and Hg were determined by instrumental and radiochemical NAA. The data obtained are compared to literature values and the total amount released is estimated. The concentrations in the condensate are compared to the amounts on the filters, enabling the identification of some of the compounds present in the gases. Objects of the investigation were Stromboli and Vulcano in Southern Italy.     

Determination of silver in SOIL-7 standard reference material by NAA

IAEA standard reference material SOIL-7 has been analyzed by both instrumental NAA and radiochemical NAA using epithermal neutron activation. These analyses confirm the NAA value of Ag in the intercomparison SOIL-7 which disagrees with some AAS values. Further geostandards were included and compared with literature data.     

ICP-AES法测定钛合金中的铝、钒、钼、铁、锆

用ICP-AES法测定钛合金中的铝、钒、钼、铁、锆,研究了高频功率、雾化压力、辅助气流量、泵速对待测元素发射谱线强度的影响,优化的测定条件为：高频功率1150W,雾化压力165．7kPa,辅助气流量0．5L／min,泵速100r／rain。该法测定结果的相对标准偏差不大于1．2％,待测元素的回收率为98．0％～101．1％。     

Determination of Cd and Pb in food slurries by GFAAS using cryogenic grinding for sample preparation

A simple method combining slurry sampling after cryogenic grinding and the use of a permanent modification of the integrated platform inside the transversely heated graphite atomizer (THGA) was proposed for the determination of Cd and Pb in foods. Potentialities of the cryogenic grinding were evaluated for grinding different materials of difficult homogenization such as high fat and high fiber tissues. Animal and vegetal samples were cut into small pieces and ground in liquid nitrogen for 2 min. Slurries were prepared directly in the autosampler cup after cryogenic grinding by transferring an exact amount of homogeneous powdered material (5-20 mg) to the cup, followed by 1.00 mL of 0.2% (v/v) HNO3 containing 0.04% (v/v) Triton X-100 and sonication for 30 s, before transferring into the platform previously coated with 250 microg W and 200 microg Rh. Use of a tungsten carbide-rhodium permanent modifier combined with NH4H2PO4 conventional modifier improves tube lifetime and increases the pyrolysis temperature for Cd. Homogeneity tests, carried out by comparing the between- and within-batch precision for each kind of sample, showed no significant differences at the 95% confidence level, indicating good homogeneity for 5-20 mg masses. Detection limits were 3.3 ng g(-1) Cd and 75 ng g(-1) Pb for 1% m/v slurries. Results for determination of Cd and Pb in foods slurries were in agreement with those obtained with digested samples, since no statistical differences were found by the paired t-test at the 95% level.     

Determination of cobalt,selenium and iodine by NAA in foodstuff by preconcentration of traces

Neutron activation analysis of cobalt, selenium and iodine requires pre-concentration of traces when the best possible conditions of sensitivity and accuracy are required at short irradiation times. The reason is ^60mCo, ^77mSe and ¹²⁸I present half-lives of 10.5 m, 17.5 s and 25 m, respectively, which do not allow neither to dissolve the sample nor to perform any radiochemical separation after irradiation. On the other hand, their emissions are located in the beginning of the spectrum (59, 161 and 441 keV, respectively) where the Compton continuum makes difficult the identification and measurement of the peaks. This paper describes how foodstuff samples are dissolved in pure HNO₃ by using conventional pressure pumps at 120–140 °C during 3–4 hours. Once cooled down the acid solution, distilled water is added and pH fixed at 1–1.5 with ammonia. 20 mg of APDC are added while stirring during 2 minutes and the solution is passed through 50 mg of activated carbon, where the Se traces are trapped. Then the filtered solution is adjusted to pH 4–6 with ammonia and passed through a fresh identical activated carbon filter where the iodine traces are caught. Finally, to the filtered solution is added 20 mg of cupferron at same pH, stirring for 2 minutes and passed through a third identical carbon filter, where the cobalt traces remain. In this way, we have the cobalt, selenium and iodine traces in three different, extremely pure carbon matrices, with a small, known mass of cobalt, selenium and iodine as background. Each filter is ready to be irradiated during a suitable time, to calculate separately at maximum sensitivity and accuracy the concentration of these three trace elements so important to human nutrition.     

Determination of elements in blood of White New Zealand rabbits by NAA

The determination of elemental concentrations for Br, Ca, Cl, Fe, K, Mg, Na, S, Sr, and Zn in blood samples from White New Zealand rabbits was performed applying the NAA technique. Twenty whole blood samples (12 male and 8 female) collected in research centers from Brazil (Aggeu Magalhães in Recife and Butantan Institute in São Paulo) were investigated, using the IEA-R1 nuclear reactor at IPEN/CNEN-SP-Brazil. These data can be used as references to perform biochemistry analyses in veterinary medicine using small quantities of whole blood (100–400 μL), simplifying the collection and the preparation of biological samples (it is not necessary to perform the serum separation nor to use specific reactants). Furthermore, the knowledge of the biochemical values in blood allows us to check the similarities with the blood estimations in human beings, which is an important condition for selecting laboratory animals. Finally, these data suggest a great similarity of the inorganic tissue profile of rabbits (White New Zealand) and humans.     

不同炊具铁、铝或镍、铬溶出量的测定

常用炊具铁、铝和不锈钢锅分别以水、水加醋煮沸10min后，用原子吸收分光光度法测定3种锅加水对应无奈的溶出量（mg／L）分别为铁11．60、铝21．41、镍0.06和铬0．07，而水加醋则其溶出量均明显增加，为加水的2．0－4．5倍。     

Determination of the contents and distribution characteristics of REE in natural plants by NAA

The concentration of 8 REEs (La, Ce, Nd, Sm, Eu, Tb, Yb and Lu) in 17 species of plants and their host soil, which were collected from a rare earth ore area located in the south of China, have been determined by INAA. The chondritic normalized REE patterns for different parts of plants (e.g., leaf stem and root) and their host soils were studied. The results showed that the concentration levels of REE for most plants in the sampling area were elevated. Particularly, the leaves of the fern (Dicranopteris dichotoma) contain extremely high concentration of the total REE (675–3358 g/g) Generally, these REE distribution patterns in every part of plants were very similar and reflected the characteristics of their host soils. However, the chondritic normalized REE patterns in some plants relative to the host soil revealed obvious fractionation, such as the depletion of the heavy REE (for fernCitrus reticulata andBrassia campestris), the heavy REE enrichment (forCamellia sinensis, Camellia oleifera andZiziphus) and the Ce positive anomaly (forGardenia jasminoides).