微波消解-氢化物发生-原子荧光光谱法测定中药材中的痕量汞

目的:建立微波消解-氢化物发生-原子荧光光谱法测定中药材中痕量汞的方法。方法:用微波消解法对几种常用中药材样品进行前处理,用氢化物发生-原子荧光光谱法测定其中痕量汞。结果:微波消解过程中,消解试剂选择硝酸+双氧水,且按3∶1比例混合时消化效果最佳,汞在浓度为0μg/L~4μg/L范围内线性关系良好,相关系数r=0.9999,方法检出限为0.014μg/L,测定汞1.0μg/ml标准溶液相对标准偏差为1.99%,测定国家一级标准物质人发(GBW09101)相对标准偏差为3.37%,且测定结果与标准含量一致。结论:该方法测定中药材中的痕量汞简便快速,准确灵敏,易于推广。     

水中痕量镉和汞的蒸气发生原子荧光光谱同时测定方法研究

[目的]建立水中镉和汞的蒸气发生原子荧光光谱同时测定方法。[方法]对镉和汞的蒸气发生条件以及原子荧光光谱同时测定镉和汞的各参数条件进行研究。[结果]在最佳测试条件下,镉方法检出限为0.03μg/L,测定相对标准偏差为1.1%～3.4%,样品加标回收率为98.6%～105%。汞方法检出限为0.0075μg/L,测定相对标准偏差为0.68%～3.2%,样品加标回收率为102%～107%。[结论]该方法灵敏度高、精密度好、操作简便快速,适于水中镉和汞的同时测定。     

氢化物发生ICP-AES与原子荧光光谱法测定化妆品砷汞含量比较

目的通过对比氢化物发生ICP-AES和原子荧光光谱法测定化妆品中砷和汞的含量,从而为化妆品中砷汞的测定提供可靠的方法。方法分别采用氢化物发生ICP-AES和氢化物原子荧光光谱法测定化妆品中砷和汞的含量。结果氢化物发生ICP-AES测定As、Hg的检出限为0.25μg/L、0.80μg/L;RSD(n=7)为1.15%、1.26%,加标回收率为100.60%~100.90%、100.30%~99.84%;原子荧光光谱法测定As、Hg的检出限为0.041μg/L、0.041μg/L;RSD(n=7)为1.96%、2.10%,加标回收率为97.90%~101.60%、98.70%~104.80%。结论两者测量的准确度和精密度都能符合要求,若只需测定砷汞,且含量低时,推荐采用原子荧光光谱法;氢化物发生ICP-AES可同时测定多种可生成氢化物的金属元素,适合大批量样品分析。     

氢化物发生-原子荧光光谱法测定水中痕量锑的研究

目的建立在硝酸介质中用氢化物发生-原子荧光光谱法测定水中痕量锑的方法。方法选择最佳的仪器条件、酸度、硼氢化钾及还原剂浓度,对方法的检出限、线性范围、精密度、加标回收率等进行了考察。结果该方法线性范围为0~15.0μg/L。检出限为0.01μg/L,相对标准偏差为2.95%~4.38%,加标回收率为锑为96%~104%。结论该方法操作简便,灵敏度高,快速,便于推广,适用于水中痕量锑的测定。     

新反应体系氢化物原子荧光法测定水中镉

目的:建立测定水中镉的新反应体系的氢化物发生原子荧光法。方法:在酸性介质中,以铁氰化钾为氧化剂,草酸为掩蔽剂,氯化钴、硫脲提高挥发性镉物质的发生效率,2%盐酸溶液为载流,先将样品中Cd+、Cd2+氧化为Cd3+,Cd3+与硼氢化钾反应生成挥发性镉的氢化物CdH3,将氢化物导入原子化器,检测其荧光强度值。结果:方法的标准曲线最佳线性范围:0~10μg/L,相关系数为0.9999,方法检出限0.017μg/L,最低检出浓度为0.051μg/L,相对标准偏差1.4%~4.0%,回收率为95.7%~104.0%。对2个标准参考物质的分析结果令人满意。结论:用该法测定水中镉,操作简便、线性关系好、检出限低、重复性好、回收率高,能准确测定水中镉。     

氢化物原子荧光光谱法测定水中铅

[目的]研究氢化物发生—原子荧光光谱法测定水中铅的方法。[方法]对AFS-930双道原子荧光光度计的工作条件及实验条件进行选择。[结果]在选定的最佳测定条件下,标准曲线线性范围为0~50μg/L。30μg/L铅标准液相对标准偏差为1.23%,检出限0.26μg/L,回收率93.2%~97.6%。[结论]该方法测定水中铅,成本低,操作简便,灵敏度高,检出限低,结果准确可靠。     

茶叶中砷的氢化物—原子荧光光度测定法

目的：寻找一种准确、快速、简便的测定食品砷含量的方法。方法：利用断续流动氢化物－原子荧光光度法，选择氢化物发生的最佳条件和最适合的还原掩蔽剂用量，进行砷测定。结果：砷含量在0-100μg/L范围内线性良好，相关系数为0.9997。最低检出量为0.08μg/L，相对标准偏差为0.77%-1.55%，回收率为97.1%-102.0%。结论：应用氢化物－原子荧光光度法测定茶叶中的砷含量，操作简便、快速、结果准确可靠、干扰少，能满足卫生标准的要求。     

水中痕量铅、镉的巯基棉富集-火焰原子吸收光谱测定法

目的 探讨水中痕量铅、镉经巯基棉富集后进行测定的方法.方法 调节水样pH=7,使水样中痕量铅、镉同时富集在巯基棉柱上,再以4 ml 0.2 mol/L HCl溶液通过巯基棉柱进行洗脱、收集,以火焰原子吸收光谱法进行测定.结果 测定的回收率为96.6%～104.0%,RSD均小于5%.4种饮用天然矿泉水样中均未检测到铅、镉,而自来水和海水中铅的含量分别为1.56、0.43μg/L;镉的含量分别为0.62、0.07μg/L.结论 采用巯基棉富集技术,以火焰原子吸收光谱法可以测定不同的水样品中痕量的铅和镉,该方法快速、准确,精密度高.     

原子荧光法测定饮用水中锡的方法改进

目的建立灵敏可行的测定饮用水中锡（Sn）的原子荧光光谱检测方法。方法通过控制反应酸度、试剂浓度等试验条件,应用氢化物发生—原子荧光法测定水样中的痕量Sn。结果在1.0～10.0μg/L的范围内,Sn的浓度和原子荧光强度成线性关系（r=0.999 9）,11次测定结果表明方法检出限为0.17μg/L,其相对标准偏差（RSD）小于4%;样品回收率在91%～99%之间。结论与Sn国标方法相比,改进的方法试剂用量减少1倍,灵敏度提高了5倍,方法简单快速,结果可靠,适用于饮用水及涉水产品中锡的测定。     

原子荧光法测定饮用水中锡的方法改进北大核心

目的建立灵敏可行的测定饮用水中锡(Sn)的原子荧光光谱检测方法。方法通过控制反应酸度、试剂浓度等试验条件,应用氢化物发生—原子荧光法测定水样中的痕量Sn。结果在1.0～10.0μg/L的范围内,Sn的浓度和原子荧光强度成线性关系(r=0.999 9),11次测定结果表明方法检出限为0.17μg/L,其相对标准偏差(RSD)小于4%;样品回收率在91%～99%之间。结论与Sn国标方法相比,改进的方法试剂用量减少1倍,灵敏度提高了5倍,方法简单快速,结果可靠,适用于饮用水及涉水产品中锡的测定。     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.