同时测定水中砷和硒的方法研究

〔目的〕建立一种同时测定水中砷和硒的方法。〔方法〕采用硝酸 -高氯酸消化样品后用双道氢化物发生原子荧光光谱法同时测定水中的砷和硒。〔结果〕方法简单、快速、准确 ,灵敏度高。方法检出限砷和硒分别为 0 .3 1μg L、0 97μg L ,平均回收率分别为 97.8%、94.0 % ,平均标准偏差分别为 1.48、3 .74。〔结论〕水中的砷和硒可以用双道氢化物发生原子荧光光谱法同时测定。     

顶空气相色谱法同时测定水中多种挥发性卤代烃

〔目的〕建立同时测定水中多种挥发性卤代烃的方法。〔方法〕采用顶空气相色谱法。〔结果〕8种卤代烃的线性方程相关系数为 0 .9982 % -0 .9996% ,检出限为 0 .0 2 -0 .2 5 μg L ,样品加标平均回收率为 95 .8% -10 2 .4%。〔结论〕本法具有干扰小、灵敏度高、检出限低、线性范围宽、操作简便、快捷、结果准确可靠的优点 ,适合水中多种卤代烃的检测分析。     

荧光分光光度法测定饮用水中挥发酚类的研究

〔目的〕分析 4-氨基安替比林氯仿萃取分光光度法、直接荧光分光光度法、正丁醇萃取荧光分光光度法三种方法测定水中挥发酚的优缺点及适用范围 ,旨在找出一个更好的检测方法测定饮用水中挥发酚。〔方法〕使用此三种方法分别测定样品及标准中的挥发酚的含量 ,比较其相关系数、线性范围、灵敏度、回收率与检出限。〔结果〕以上三种方法的相关系数分别为 0 .9988、0 .9998、0 .9994,线性范围分别为 0 -0 .0 40mg L、0 -0 .0 40mg L、0 -0 .0 2 0mg L ,平均回收率分别为 95 .9%、10 0 .2 %、96.9% ,检出限分别为 0 .0 0 2mg L、0 .0 0 10 7mg L、0 .0 0 0 3 3mg L ,灵敏度分别为 11.177、3 2 61.9、3 745 6。〔结论〕正丁醇萃取荧光分光光度法有很好的灵敏度、回收率、检出限和相关系数 ,方法较简单且试剂毒性小 ,适合饮用水中挥发酚测定的国家标准要求 ,可以取代 4-氨基安替比林氯仿萃取分光光度法成为国家标准方法。     

流动注射测定饮用水中挥发性酚类化合物方法的研究

〔目的〕为获得一种方便、准确和灵敏测定水中挥发性酚类化合物的检测方法。〔方法〕应用流动注射技术在线测定饮用水中挥发性酚类化合物 ,水样在线蒸馏后不经氯仿萃取直接进行定量分析。〔结果〕方法的最低检测浓度为 1.5 μg/L :线性范围 1.5 μg L～ 5 0 μg/L呈直线 ,其相关系数r≥ 0 .999;相对标准偏差为 2 .3 %～ 7.4% ;加标回收率为 88.9%～ 10 9%。〔结论〕本方法操作简便、灵敏度高、线性范围、精密度和准确度符合检测要求。     

吹扫捕集与气相色谱-质联联用法测定饮用水中苯系物

〔目的〕用吹扫捕集与气质联用技术对饮用水中苯、甲苯、乙苯、邻、间、对二甲苯、异丙苯、苯乙烯的测定进行了研究。〔方法〕该法采用HP -INNOWAX色谱柱使一直是分离难题的间、对二甲苯得到了很好的分离。〔结果〕对 8种苯系物进行了线性、回收率、精密度试验 ,其平均回收率为 95 .5 %-10 3 %(n =6) ,相对标准偏差为 1.44 %-4 .65 %(n =6) ,最低检出限为 0 .2 -0 .5 μg L。〔结论〕测定结果表明 ,该法操作简单 ,重现性好 ,灵敏度高 ,完全可以满足饮用水中挥发性苯系物的测定。     

离子色谱法测定饮用水中氯含量的不确定度评价

〔目的〕进行离子色谱法测定饮用水中氯含量不确定度分析。〔方法〕应用测量不确定评定理论 ,分析离子色谱法测定水中不确定度。〔结果〕得出测定水中氯含量的相对不确定度 ,U(p =99 7% ) =2 0 %。〔结论〕该不确定度评价方法在实际工作中有较强的实用价值     

气相色谱法测定动物性食品中二氯二甲吡啶酚的研究

〔目的〕建立一种快速测定动物性食品中二氯二甲吡啶酚的方法。〔方法〕在超声振荡下用甲醇提取动物性食品试样中残留的二氯二甲吡啶酚 ,提取液通过氧化铝柱和阴离子交换柱进行净化 ,然后经乙酰化后 ,用气相色谱法测定。〔结果〕方法在 0 -2 .5 μg ml范围呈良好的线性关系 ,其相关系数为 0 .9992 ;方法最小检测量为 8.0× 10 - 3mg Kg ;方法的平均回收率大于 90 .0 % ,相对标准偏差为 4.2 %。〔结论〕该方法是一种快速、简便、灵敏度较高的检测动物性食品中二氯二甲吡啶酚的方法。     

分光光度法测定粮食中的维生素B1

〔目的〕寻找一种测定食品中硫胺素 (VB1)的简单快速的方法。〔方法〕在氢氧化钠和碳酸氢钠混合溶液的缓冲介质中 ,对氨基苯磺酸重氮盐与硫胺素发生偶氮反应 ,用 72 2光栅分光光度计在 5 2 0nm波长下进行测定。〔结果〕方法的线性范围为 0 .0 0 6 6～ 0 .0 5 0 0mg/ml;检出限为 0 .0 0 6 6mg/ml。平均加标回收率为 84 .8%～ 10 1.6 % ,相对标准偏差为 3.6 %～ 7.0 %。〔结论〕方法简单、快速、测定干扰小 ,结果与标准测定方法一致。     

中性红-H2O2体系催化动力学光度法测定痕量铝

〔目的〕探讨研究一种新的痕量铝测定方法。〔方法〕基于pH3 .6的乙酸 -乙酸钠缓冲介质中Al3 对过氧化氢氧化中性红 (NR)褪色反应的催化作用 ,应用了催化动力学光度法测定痕量铝。〔结果〕该法的适宜反应条件 ,方法的线性范围为 0 -10 0ng ml ,检出限为 1.2ng ml。〔结论〕方法用于样品中痕量铝的测定 ,结果满意。     

离子色谱法测定牙膏中的锶

〔目的〕采用离子色谱法测定牙膏样品中的锶。〔方法〕选择 2 0mmol L甲磺酸作为淋洗液 ,流速 0 60ml min ,IonPacCS12阳离子分离柱分离和测定。本文还进行了钙离子及pH值的干扰试验。〔结果〕本法线性范围大于 0 .0 0 5～13 .0mg L ,相关系数大于 0 .9972 ,方法检出限为 0 .0 41mg L ,相对标准偏差小于 1.0 %,加标回收率为 82 %～ 10 9%。〔结论〕本法操作简单 ,灵敏度较高 ,线性范围宽 ,不失为一种较好的测定方法。     

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.     

The occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

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.