生物样品大型快速灰化装置与大量生物样快速灰化方法的研究及其应用

叙述了生物样品快速灰化装置的组成、结构与特点,以及生物样品快速灰化的条件试验,样品量与灰化时间的关系,灰化温度与灰化容器等试验,在此基础上建立了生物样品 的快速灰化方法及其实际应用。该装置由快速灰化炉、供气系统和温度程序控制柜三部分组成。经试验结果表明,该装置有以下特点:(1)灰化快速、耗电量少;(2)一次能灰化的样品量大;(3)灰样洁白(或洁净)、疏松、易溶,残炭量少;(4)可直接灰化鲜样品。该装置的研制成功,为环境生物样品与核医学、医学、农业与食品等研究中的样品预处理提供了快速灰化的新设备与新技术。     

生物样品快速灰化方法的研究

本文报道生物样品快速灰化时氧化性气体的流量、样品量与灰化时间的关系及灰化温度等实验,在此基础上建立了生物样品快速灰化方法。大量生物样品的灰化结果表明,该法适用于大量样品的处理,灰化迅速,灰样质量好,并可直接灰化鲜样。     

含~3H标记物的生物样品的制备与测量

在液体闪烁技术中,消化法与燃烧法制备的样品同属均相测量。我们曾用HClO_4-H_2O_2消化制备含~3H的生物样品,遇到了测量效率过低、各种来源样品间的淬灭度相差较大等问题,后来采用了氧瓶燃烧法解决了这个问题。由于药物代谢研究中每批实验取自各种来源的生物样品很多,为此,我们结合本实验室条件,建立了一种用燃烧法制备含~3H标记物的生物样品,在LKB1215型液体闪烁仪上测量放射性的规范化操作程序。     

大型生物样品快速灰化装置的研制

本文研制的大型生物样品快速灰化装置由快速灰化炉、供气系统和温度程序控制柜三部分组成,适用于含低水平放射性与痕量元素的生物样品的快速灰化。试验结果表明该装置具有以下特点:(1)灰化时间短,耗电量少;(2)一次灰化的样品量大;(3)灰样洁白(或洁净)、疏松、易溶、残炭量少;(4)可直接灰化鲜样。     

基于微波前处理技术快速测定生物样品中放射性核素的γ能谱方法

建立以大容量微波干燥碳化灰化一体装置为载体制备生物灰样、采用高纯锗γ能谱法直接测量生物灰样放射性核素的生物样品分析测定方法，实现核电厂周边环境生物样品中γ放射性核素活度浓度的快速测定。与传统灰样制备法对比研究结果表明：该微波灰样制备法可使生物样品制样效率提高约2～5倍，平行样相对偏差小于14.8%，加标回收率为87.0%～116%。采用配对t检验法验证，二者之间无显著性差异。该方法具有准确度高、分析效率高、操作简单、安全环保等优点，是快速测定生物样品中γ放射性核素活度浓度的理想方法。     

生物样品快速灰化装置用于处理生物废物的可行性

本文研究了用生物样品快速灰化装置处理生物废物的可能性。该装置的特点是加速炭化和灰化，灰化温度为３５０－４５０℃，灰化时间为５－７ｈ，操作简便。用该装置灰化处理了兔子和白鼠尸体，处理结果表明，一炉可处理３ｋｇ动物尸体，灰样不沾容器内壁，便于收集和进行水泥固化，灰化温度不超过４５０℃，不会引起放射性核素的严重挥发损失，废物中所含放射性核素基本上保留在灰分中。     

充氧加助剂干灰化法研究——生物样品的前处理

研究了一种可用于计量认证复查中样品分析数据考核的快速干灰化法——充氧加助剂干灰化法。生物样品体积大,无机元素含量低,试样基体为有机物,给分析溶样带来一定困难。为提高测定方法的灵敏度,减小基体效应,溶样前须先将样品灰化,分解有机物,缩小体积。 样品考核必须在24h内完成,灰化时间应尽量短。高温灰化是提高灰化速度的有效方法,但温度提高会增大元素的损失率。综合以前的工作,采用充氧和加助氧化剂两种方法加快氧化速度,在不太高的炉温下,短时间灰化大体积的生物样品。     

环境植物样品中~(131)I、~(125)I的测定

本文描述了一个测定环境植物样品中~(131)I、~(125)I的分析方法。采用0.5NNaOH溶液浸泡样品、H_2O_2作助灰化剂,2小时可灰化500克鲜样。用Cl_4萃取、AgI沉淀,低本底β计数器测量的流程,对大气沉降物污染的植物样品的全程回收率为70—80％;测量灵敏度为8×10~(-13)居里/公斤;对环境中裂变核素的去污系数在10~4以上;分析6个样品约8小时。~(131)I污染水平较高的样品,用γ谱仪直接测量和放化分析后的β测量,其结果基本一致;β、γ测量的放化回收率与化学回收率之比分别为0.99和1.00。该方法操作简单、灵敏、快速、可靠,不需要特殊设备和试剂,适用于~(131)I、~(125)I的大量常规分析。     

供锶-90和铯-137分析比对用的芦苇和茶叶样品的制备

本文报道了供实验室进行~(90)Sr 和~(137)Cs 分析比对用的芦苇和茶叶样品的制备和均匀性检查的方法。样品从核企业周围地区采集,经烘干和初步破碎后用超微粉碎机粉碎,在混样器上混合。装瓶后的样品随机抽取一部分进行灰化,测量其灰重,γ、β放射性和钾含量;用 F 检验和 t 检验的方法检查样品的均匀性。     

公斤级生物样品微波灰化法与电炉-马弗炉法的对比

为解决辐射环境监测中公斤级生物样品灰化慢的难题,建立了一种公斤级生物样品微波灰化技术。为考察该灰化方法的效果,开展了微波灰化法与国标方法电炉-马弗炉法的对比研究。结果表明：微波法的灰化速度快,其炭化时间、总灰化时间分别约为后者的1/7～1/3、1/2;Cs元素的回收率从大于70%提高到大于80%;杂质引入量显著降低,Fe元素的引入量为后者的1/20。此外,微波法还具有自动化程度高的优势。对比研究表明,微波法优于电炉-马弗炉法,能满足辐射环境监测生物样品的处理要求。     

N_2O Decomposed by Discharge Plasma with Catalysts

A great deal of attention has been focused on discharge plasma as it can rapidly decompose N_2O without additives,which is not only a kind of greenhouse gas but also a kind of damages to the ozone layer.The thermal equilibrium plasma is chosen to combine with catalysts to decompose N_2O,and its characteristics are analyzed in the present paper.The results indicate that NO and NO_2 were formed besides N_2 and O_2 during N_2O decomposition when N_2O was treated merely by discharge plasma.Concentration of NO declined greatly when the discharge plasma was combined with catalysts.Results of Raman spectra analysis on CeO_2,Ce_(0.75)Zr_(0.25)O_2and Ce_(0.5)Zr_(0.5)O_2 imply that the products selectivity has been obviously improved in discharge plasma decomposing N_2O because of the existence of massive oxygen vacancies over the composite oxide catalysts.     

Bromate removal by gamma irradiation in aqueous solutions

Bromate(BrO_3) is a disinfection by-product in drinking water, and its removal is very difficult especially at low levels.60 Co gamma rays were used to remove BrO_3in aqueous solution in this study. The effects of absorbed doses, BrO_3initial concentration, gas saturation, p H value and coexisting anions(Cl, NO 3, SO2 4and HCO 3=CO_3~(2 -))on BrO_3reduction were evaluated. After 4.0-k Gy irradiation of air-equilibrated solution of 30.7 lg/L BrO_3, the residual BrO_3was 8.3 lg/L, which is below the maximum contaminant level of drinking water. The BrO_3reduction rate increased with the dose, in the order of N2[ air [ O_2[ N_2O atmosphere under similar conditions. The results also show that high p H favored the BrO_3removal. According to the experimental results, it can be concluded that the efficiency of decomposing BrO_3by reactive species followed the order of e aq[ H [ HO_2 [ O_2. Coexisting Cl, HCO 3=CO_3~(2 -)and SO2 4ions have little effect on BrO_3removal, whereas NO_3can inhibit its removal as a result of competition with BrO_3for e aq.     

水溶液体系制备铀电镀靶

对影响电沉积铀的主要因素进行了试验和讨论,在电沉积法制备铀靶的初期实验中,选用不锈钢作为电沉积铀的靶片,用UO2(NO3)2和(NH4)2C2O4作为镀液,pH值为2~3。对影响电沉积铀的主要因素进行了试验和讨论,并用分光光度法分析了电镀残液中的铀含量,最终制得的铀靶的沉积厚度达到8~10mg/cm2,镀层牢固、均匀,电镀效率大于80%。     

生物样品中铅在不同干燥和灰化过程中的损失研究

前言 生物样品中微量元素分析往往需预先经过干燥和灰化处理。了解在干燥和灰化过程中生物材料中微量元素的损失,对于选择正确的干燥和灰化方法,得到准确的分析结果是至关重要的。     

大量生物样品灰化的简易方法

本文介绍了一种大量生物样品的简易灰化方法。该方法在传统的马弗炉灰化法基础上稍加改进,即在样品灰化过程中炉门始终启开,因而提高了灰化速度,灰化质量不亚于原方法。     

离子色谱法（IC）测定高放废液中若干阴离子浓度

采用离子色谱法(IC)测定大量NO_3离子存在下的微量或少量F、Cl,,NO_2和PO_4~3离子浓度。使用Y_(2X-8)阳离子交换树脂预处理柱除去试样中可能存在的阳离子,特别是大量的过渡金属和重金属离子。以Na_2CO_3-NaHCO_3淋洗液稀释试样,有效地抑制水负峰对F~-、Cl~-离子测定的影响。选择合适的样品稀释倍数,将大量存在的NO_3离子对其它阴离子测定的干扰排除,以使方法在用于高放废液中的F、Cl、NO_2和PO_4~3离子的测定中具有较高灵敏度。     

Synergistic effects of 4-nitrophenol degradation using gamma irradiation combined with a advanced oxidation process

The radiation-induced degradation of 4-nitrophenol(4-NP) was performed in combination with a Fenton reagent, H_2O_2, and Ti O_2 nanoparticles to investigate the synergetic effects of radiolytical degradation combined with other advanced oxidation processes. The experimental results indicated that the degradation efficiency of 4-NP was 87.5, 57.4, and 41.0 % at a dose of 20 k Gy when its initial concentration was 100, 200, and 350 mg/L, respectively. Radiation combined with H_2O_2, the Fenton method,and Ti O_2 remarkably increased the degradation efficiency of 4-NP, showing the synergetic effects. Radiation may enhance the biodegradability of 4-NP, suggesting that it has the potential to be used as a pretreatment method in combination with the biological method for the treatment of industrial wastewater containing toxic organic pollutants. Major intermediates during the 4-NP degradation process were identified and a possible degradation pathway was tentatively proposed.     

High-efficiency removal of NO_x using dielectric barrier discharge nonthermal plasma with water as an outer electrode

With the rapid increase in the number of cars and the development of industry, nitrogen oxide(NO_x)emissions have become a serious and pressing problem. This work reports on the development of a water-cooled dielectric barrier discharge reactor for gaseous NOxremoval at low temperature. The characteristics of the reactor are evaluated with and without packing of the reaction tube with 2 mm diameter dielectric beads composed of glass, ZnO, MnO_2, ZrO_2, or Fe_2O_3. It is found that the use of a water-cooled tube reduces the temperature, which stabilizes the reaction, and provides a much greater NO conversion efficiency(28.8%) than that obtained using quartz tube(14.1%) at a frequency of 8 k Hz with an input voltage of 6.8 k V. Furthermore,under equivalent conditions, packing the reactor tube with glass beads greatly increases the NO conversion efficiency to 95.85%. This is because the dielectric beads alter the distribution of the electric field due to the influence of polarization at the glass bead surfaces, which ultimately enhances the plasma discharge intensity. The presence of the dielectric beads increases the gas residence time within the reactor. Experimental verification and a theoretical basis are provided for the industrial application of the proposed plasma NO removal process employing dielectric bead packing.     

过氧化氢湿法氧化模拟有机污物的研究

用过氧化氢湿法氧化处理有机污物,研究了过氧化氢的投加量和投加方式,催化剂以及pH值等对反应的影响。结果表明,为提高H2O2的利用率,H2O2应以间歇式投加,选取Fe^2 作催化剂,体系pH值为1～2。为保证反应快速启动和平稳进行,反应时将催化剂总投加量的1／3提前与要分解氧化的物质混合一段时间,剩余2／3在反应进行中连续定量滴加,并于反应结束前半小时投加完毕。正交试验表明,分解2．00g界面污物的最佳实验条件为：pII-1．10mL30％H2O2溶液,10mL 0．1mol／L Fe^2 溶液。反应结束时,反应釜底部的白色残余物经红外分析和元素分析表明主要是磷酸盐。H2O2湿法氧化能够有效分解TBP／OK,HDBP／OK溶液和界面物。