气相分子吸收光谱法测定含有还原性物质水样中氨氮的研究

气相分子吸收光谱法测定富含还原性物质的氨氮水样时,还原性物质会消耗次溴酸盐氧化剂使得氨氮的转化率变低,从而导致测定结果偏低,单一的提高次溴酸盐用量效果并不明显。考察了双氧水、高锰酸钾和重铬酸钾三种氧化剂对氨氮测定的影响;并对最佳氧化剂添加量进行了分析;对比了添加重铬酸钾后,气相分子吸收光谱法与纳氏试剂法测定12个不同类型水样和3个质控样的相对误差(RE%),并用SPASS软件进行了配对样本t检验。结果表明,饱和重铬酸钾为最佳氧化剂;最佳添加量为0.1mL;添加重铬酸钾后,气相分子吸收光谱法测定结果与纳氏试剂法相对误差最小,相对误差(RE%)从1.7%～86.2%下降至0.64%～16.2%;配对样本t检验结果为:t=1.956,P=0.071 0.05,纳氏试剂法和气相分子吸收光谱法(加抗干扰剂)测定结果无显著性差异。因此,重铬酸钾可作为《水质氨氮的测定气相分子吸收光谱法》(HJ/T 195-2005)测定含有还原性物质水样中氨氮的一种有效抗干扰剂。     

水中亚硝酸盐氮两种测定方法比较

对亚硝酸盐氮的两种测定方法——分光光度法和气相分子吸收光谱法进行了对比试验,测定了标准物质、地下水、生活污水、某地表水、某湖泊水中的亚硝酸盐浓度及加标回收率。结果表明:采用分光光度法和气相分子吸收光谱法测定结果和准确度均可满足实验要求,但是采用分光光度法需对水样进行预处理以去除干扰,而采用气相分子吸收光谱法测定水样不需要进行预处理,实验时间相对较短,更适合一些复杂水体中的亚硝酸盐氮的测定。     

气相分子吸收光谱法测定空气中的氨

文章探索利用气相分子吸收光谱法测定空气中的氨。用稀硫酸吸收液采集空气中的氨,将其转化为硫酸铵,通过次溴酸盐将其氧化成等量的亚硝酸盐,利用气相分子吸收光谱仪测定亚硝酸盐氮的浓度,从而测出空气中氨的浓度。应用气相分子吸收光谱法测定空气中的氨方法准确可靠。     

气相分子吸收光谱法测定废水中的氨氮

文章应用气相分子吸收光谱仪测定废水中的氨氮,对其工作曲线、准确度、精密度、稳定性以及加标回收率进行了实验,测得该生活污水处理厂进、出口浓度分别为1.176,0.181mg/L,7次重复测定的标准偏差分别为0.448%,0.674%。在两种实际样品中分别加入0.5mg/L的标准浓度样品进行加标回收率测试,回收率分别为99.54%,99.58%。结果表明,该实验方法简便、快捷、易操作、准确度及精密度良好。与纳氏试剂法相比较具有自动化程度高、测定速度快等优点。     

环境监测中仪器分析方法不确定度的评估(Ⅱ)——原子吸收光谱分析中的测量不确定度

通过对环境样品分析中常用的原子吸收光谱法测量不确定度分量的分析,探讨了原子吸收光谱法测量不确定度的评估方法,针对不同环境基体样品、不同测定组分以及不同前处理方法的扩展不确定度进行了评定。原子吸收光谱分析中的测量不确定度主要来源于样品称量、消化液定容、仪器漂移及由吸收值通过标准曲线拟合求浓度部分,其中最主要的分量是由吸收值通过标准曲线拟合求样品溶液浓度时引起的测量不确定度。     

气相分子吸收光谱法测定水中硫化物

采用气相分子吸收光谱法测定水中硫化物的含量,对方法的操作过程及精密度、准确度等问题进行了探讨,结果表明,方法的检出限为0.005mg/L,6次重复测定的精密度为0.4%,能满足清水、污水、海水和工业废水中硫化物样品的分析测试要求。     

密封消解法测定高氯离子含盐废水COD_(Cr)的探讨

针对国标重铬酸钾法测定高氯离子含盐废水CODCr时的不足,提出用密封消解法来测定高盐废水CODCr的观点,通过丁酮氧化率、氯离子干扰、混配水样和实际水样测定结果的比较,对国标法和密封消解法进行了验证。试验结果表明:在测定高氯离子含盐废水CODCr值时,密封消解法优于重铬酸钾法,能够真实准确地反映废水的CODCr。     

标准加入分光光度法测定废水中氨氮

本文将标准加入法运用于分光光度分析中，排除了废水氨氮测定中复杂的基体干扰，操作简便，结果准确，适合于单个或小批量水样的直接测定。     

微波消解-紫外法测定水中总氮与国标方法的比较研究

将微波消解-紫外法测定总氮从方法检出限、校准曲线、精密度和准确度、实际样品测定4个方面与国标紫外法作了比较研究,进行了消解时间比对实验,说明了微波消解-紫外法测定总氮的注意事项。结果表明,微波消解-紫外法检出限为0.115 mg/L,高于国标紫外法;校准曲线具有较好线性相关系数,斜率与国标紫外法一致;方法精密性和准确性较好,实际样品测定结果与紫外法保持一致,在总氮监测中具有可行性。微波消解-紫外法节省了总氮监测的整个用时。     

COD测定方法的发展与研究动态

本文较为全面地论述了COD测定方法的发展与研究现状。在论述了国标中COD标准方法不足之处的基础上,本文就标准方法的众多改进措施分类进行了比较与探讨,包括消解方法的改进、替代催化剂的研究以及氯离子干扰的消除,然后介绍了相关系数法、电化学法、分光光度法和流动注射法等COD测定替代技术。本文认为,研究试剂用量少、无污染的绿色COD测定方法具有重要而积极的意义,而研究适应性强、运行可靠、性价比高的COD在线监测仪则是COD监测的发展趋势。     

Levels of lead in blood in residents of Kuwait

Following an examination of blood samples from 1000 persons from Kuwait, a number of important differences in the levels of lead in the blood were noted. There were significant differences between the sexes living in the same residential area. Certain significant lead in blood differences were also found between females and males who dyed their hair, and between smokers and non-smokers. Lead in blood concentrations were also tested for the various blood groups of the respondents. It was noted that O⁺ blood group respondents were found to have higher lead levels than those of other major blood groups.     

Closure of Disputes in Assessments of Climate Change in The Netherlands

2 greenhouse gases in assessment studies. For the cases studied, we identify variability in the assessment reports in the Netherlands during the pre-IPCC period. In the Netherlands arena, the assessments in this period can be seen as exponents of two different lines, a Netherlands line and an international line. We seek to identify what factors were decisive in the selection processes that resulted in the closure of visible disputes (visible in or across the assessment reports) for both cases. Our analysis reveals a remarkable difference in the adoption behavior of two Dutch assessment groups despite a large overlap in membership. We provide evidence that it is not the paradigmatic predisposition of the experts in the committee that was decisive for the closure of visible disputes, but it was the context in which the experts operated and the commitments they had made in each setting.     

Assessment of flooding impacts in terms of sustainability in mainland China

An understanding of flood impact in terms of sustainability is vital for long-term disaster risk reduction. This paper utilizes two important concepts: conventional insurance related flood risk for short-term damage by specific flood events, and long-term flood impact on sustainability. The Insurance Related Flood Risk index, IRFR, is defined as the product of the Flood Hazard Index (FHI) and Vulnerability. The Long-term Flood Impact on Sustainability index, LFIS, is the ratio of the flood hazard index to the Sustainable Development Index (SDI). Using a rapid assessment approach, quantitative assessments of IRFR and LFIS are carried out for 2339 counties and cities in mainland China. Each index is graded from ‘very low’ to ‘very high’ according to the eigenvalue magnitude of cluster centroids. By combining grades of FHI and SDI, mainland China is then classified into four zones in order to identify regional variations in the potential linkage between flood hazard and sustainability. Zone I regions, where FHI is graded ‘very low’ or ‘low’ and SDI is ‘medium’ to ‘very high’, are mainly located in western China. Zone II regions, where FHI and SDI are ‘medium’ or ‘high’, occur in the rapidly developing areas of central and eastern China. Zone III regions, where FHI and SDI are ‘very low’ or ‘low’, correspond to the resource-based areas of western and north-central China. Zone IV regions, where FHI is ‘medium’ to ‘very high’ and SDI is ‘very low’ to ‘low’, occur in ecologically fragile areas of south-western China. The paper also examines the distributions of IRFR and LFIS throughout mainland China. Although 57% of the counties and cities have low IRFR values, 64% have high LFIS values. The modal values of LFIS are ordered as Zone I < Zone II ≈ Zone III < Zone IV; whereas the modal values of IRFR are ordered as Zone I < Zone III < Zone IV < Zone II. It is recommended that present flood risk policies be altered towards a more sustainable flood risk management strategy in areas where LFIS and IRFR vary significantly, with particular attention focused on Zone IV regions, which presently experience poverty and a deteriorating eco-system.     

生物体内有机氯农药的研究进展

有机氯农药是高残留农药，进入生物体后会长期残留，对生物体产生危害。近年来，生物体中的有机氯农药的研究越来越引起各国环境化学家、生态学家的重视，渐渐成为环境化学、生态毒理学研究的热点之一。本文总结了近年来国际上有关生物体内有机氯农药的研究进展情况，以及所取得的主要研究成果。     

生态功能区划在县域可持续发展指标体系中的应用

在分析县域可持续发展指标体系特点的基础上,从生态功能区划依据的原则、目标等方面,深入论述了生态功能区划在县域可持续发展指标体系中的三方面作用,提出了应用生态功能区划结果对某一区域内不同县域的可持续发展状况分类别进行评价的观点。     

铜陵铜官山矿区土壤重金属污染状况研究

通过野外调查和室内分析,研究了铜陵铜官山铜矿区土壤重金属含量,并采用单因子指数法和内梅罗指数法对铜官山土壤污染程度进行评价.研究结果表明,研究区土壤Cu、Zn、As、Hg平均含量高于当地的土壤背景值,土壤已受Cu、Zn、As重污染,受Hg轻污染.不同样点土壤重金属含量存在较大差异,其中处于选矿厂附近的9到16号样点土壤重金属污染情况较其它样点相对较重,15和16号样点的重金属单项污染指数和综合污染指数都很高,污染状况在所有样点中最为严重.     

Role of Wild Game in the Diet of Recreationists in South Carolina

Risk assessors have devoted considerable attention to the consumption of fish in the diet of recreational and subsistence anglers, but little attention has been directed toward the percentage that wild game contributes to total protein intake for people who engage in hunting and fishing. While recall studies have limitations, the relative errors should be similar for different types of fish and game. We interviewed 454 people attending the Palmetto Sportsmen's Classic in South Carolina to determine their consumption patterns of domesticated animals, fish (both wild-caught and commercial) and wild game. The percentage of people who consumed each type of meat was: chicken (98%); beef (95%); wild-caught fish (79%); deer (79%); restaurant fish (73%); pork (71%); dove (47%); commercial fish (41%); wild turkey (40%), duck, squirrel and self-caught quail (about 25% each); restaurant quail (10%); and raccoon (11%). Although a similar proportion of white respondents and black respondents consumed wild game overall (90%), there were ethnic differences in the number of meals of wild-caught fish and game. Black respondents ate more wild-caught fish, rabbit, raccoon and squirrel, and less deer, than did white respondents. Wild-caught fish and game made up 50% of the meat and fish diet of black sportsmen, but only 32% for whites. Wild-caught fish and game were being eaten disproportionately more by low-income black respondents, while more deer was consumed by higher-income black respondents. The data suggest that managers and planners should take into account age, ethnicity and income when (1) conducting exposure assessments, (2) considering consumption patterns for wild-caught fish and game and (3) managing risk from wild-caught fish and game. The data will be especially useful to policy makers and risk managers who are designing consumption advisories, for risk communicators in identifying the target audience and for managers designing long-term stewardship for sites with contamination.     

高校参与社区精神文明建设的思考

高等院校汇集了多方面的人才,是社会主义精神文明建设的重要阵地。如何发挥其优势为社区精神文明建设服务?本文从多方面论述了高校主动参与社区精神文明建设的指导思想、意义、优势、思路和途径。     

攀西地区主要蔬菜和水果基地土壤Zn污染调查研究

根据各水果、蔬菜基地的分区定点采样结果的对比分析,研究了四川省攀西地区主要蔬菜和水果基地土壤中Zn含量。结果表明,该区土壤Zn平均值范围在75．0～160mg／kg之间。各基地土壤平均锌含量顺序为：撒莲蔬菜基地〉攀莲蔬菜基地〉会理石榴基地〉大田石榴基地〉西区芒果、桂圆基地〉仁和芒果基地〉盐边芒果、枇杷基地。7个基地中有3个基地的土壤锌含量不同程度超过土壤环境质量Ⅱ级标准,其中以大田石榴基地超标最高（16％）,平均值却是两个蔬菜基地最高。     

国土资源开发利用的综合效益分析

用定量与定性相结合的方法 ,系统分析了国土资源在开发过程中所表现出来的各种社会、经济和生态方面的数量关系和指标 ,并用经济学的基本模型 ,从国土资源开发的社会效益、经济效益和生态效益上总结了这种关系。最后提出了国土资源开发利用的综合效益就是社会效益、经济效益、生态效益的统一 ,经济效益是社会效益和生态效益基础的观点。