水中硝酸盐氮的麝香草酚分光光度测定法

目的 建立水中硝酸盐氮(NO3-)的快速测定方法.方法 在浓硫酸存在下,麝香草酚与水中硝酸盐反应生成硝基化合物,加入氨基磺酸铵和硫酸银消除干扰后,滴加氨水使溶液呈碱性,硝基化合物在此碱性溶液中发生分子重排,产生黄色化合物,在波长415 nm比色定量.结果 NO3-浓度在0～15.0 mg/L范围内与吸光度呈良好的直线关系,r=0.999 8,最低检测质量浓度为0.25 mg/L,回收率为96%～108%,RSD为1.6%～4.0%.该法与紫外分光光度法测定结果差异无统计学意义(P＞0.05).结论 该方法操作简捷、灵敏、快速、准确.适用于水中NO3-的测定.     

紫外分光光度法测定生活饮用水中硝酸盐氮初步研究

目的 :旨在寻找一种较国标法更简单、快速、准确的生活饮用水中硝酸盐氮检测方法 ,以紫外分光光度法测定生活饮用水中硝酸盐氮。方法 :用 1mol/L盐酸酸化水样后 ,直接用紫外分光光度计测定水样中硝酸盐氮含量。结果 :本法标准曲线线性关系好 ,相关系数r =0 .9998,最低检出浓度为 0 .0 11mg/L ,RSD均 <5 %。标准质控样测定值与已知定值的相对偏差为 - 0 .6 0 %～ 0 .75 % ,平均加标回收率为 10 0 .7% ,与国标法(二磺酸酚法 )比较 ,差异无显著性 ,P >0 .0 5。结论 :本法简便快速、准确、灵敏度高 ,推荐本法为生活饮用水中硝酸盐氮检测方法。     

高效液相色谱-串联质谱联用法测定饮用水和水源水中莠去津、呋喃丹和甲基对硫磷

目的:建立液相色谱-串联质谱法测定饮用水和水源水中莠去津、呋喃丹和甲基对硫磷等3种农药的方法,以完善现有国标《生活饮用水卫生标准检测方法》有关内容。方法:采用直接进样方式,用高效液相色谱-串联质谱(HPLC/MS/MS)测定饮用水和水源水中的3种农药。水样经0.22μm微孔滤膜过滤,采用HPLC/MS/MS电喷雾电离(ESI),多反应监测(MRM)模式检测,外标法定量。结果:方法的线性范围为0.5μg/L～50.0μg/L,线性相关系数在0.9991-0.9998之间,检出限在0.03μg/L～0.05μg/L之间;两个水平的平均加标回收率范围在92.0%～98.0%之间;相对标准偏差(RSD)均小于8.83%。结论:该方法用于测定饮用水和水源水中3种农药具有操作简单、干扰少、快速、准确可靠等特点,符合国家卫生标准方法建立的相关要求。     

饮用水中氰化物的流动注射分析测定法

目的建立流动注射分析法检测生活饮用水中氰化物的方法。方法采用Lachat QC8500流动注射分析仪,样品经125℃在线蒸馏,与氯胺-T反应生成氯化氰,再与异烟酸-巴比妥酸反应生成紫蓝色染料,在600 nm处比色测定。结果水中氰化物在1.00~200μg/L范围内有好的线性,相关系数r=0.9999,检出限为0.29μg/L。水样的加标回收率为98.2%~104%,相对标准偏差在0.60%~3.83%之间。结论所建立的分析方法快速、准确,灵敏度高,可用于测定饮用水中的氰化物。     

麝香草酚-微量分光光度法测定水中硝酸盐氮

目的建立测定生活饮用水中硝酸盐氮的麝香草酚-微量分光光度法。方法水中硝酸盐和麝香草酚在浓硫酸溶液中反应生成硝基化合物,加入氨基磺酸铵和硫酸银溶液消除干扰后,加入氨水使溶液呈碱性,硝基化合物在碱性溶液中发生分子重排,生成黄色化合物,采用微量自动分析仪在波长415nm处比色定量。结果硝酸盐氮浓度在0.5~10mg/L的范围内与吸光度呈良好的线性关系,r=0.999 7,方法的检出限为0.3mg/L,回收率为90.0%~104.0%,RSD为1.96%~2.86%。该法与离子色谱法测定结果差异无统计学意义。结论该方法所用化学试剂少、操作简单、灵敏度高、重现性好,适用于水中硝酸盐氮的测定。     

双柱定性气相色谱电子捕获检测器测定上海市饮用水中微量碘化物

目的 对目前国家生活饮用水标准检验方法中气相色谱测定碘化物的色谱条件、定性定量方法等进行改进和优化,并以该法测定上海市饮用水中碘化物含量.方法 先以气相色谱与质谱联用鉴定衍生化产物碘丁酮,再用双毛细管柱配合电子捕获检测器对碘丁酮进行定性定量分析,最后分别采集上海市以长江、黄浦江及其内河为水源的3家水厂原水和出厂水各100 ml测定水样中碘化物水平.结果 经质谱鉴定发现碘化物衍生化后生成碘丁酮存在2个同分异构体,即1-碘-2-丁酮和3-碘-2-丁酮.采用双毛细管柱定性分析显示,碘丁酮分离度好,整个色谱分离时间为19.33 min.选择响应值较高的3-碘-2-丁酮进行定量检测,方法线性范围为1～100μg/L,确定系数r2=0.9997;方法检出限为13 ng/L;样品加标回收率为97.68%～104.37%,相对标准偏差为2.14%～4.41%.该方法测定3家上海市不同水源水厂的原水和出厂水中碘化物含量结果发现,原水中碘化物浓度以黄浦江最高(15.14μg/L),内河次之(6.97 μg/L),长江最低(3.55μg/L);除水厂2出厂水中碘化物浓度下降外(水厂2原水中碘化物浓度为15.14 μg/L,出厂水中为1.81μg/L),水厂1和3均呈略微上升(水厂1和3原水中碘化物浓度分别为3.55、6.97 μg/L,出厂水中分别为5.92、9.62μg/L).所有水样经平行双样测定的相对偏差均≤9.73%.结论 改进后的方法灵敏度更高、定性定量更准确,适用于水中微量碘化物的分析.     

离子色谱法测定饮用水中的余氯

目的建立测定生活饮用水中余氯的离子色谱分析法。方法向饮用水中加入过量的亚硝酸钠溶液,取其与余氯反应后的溶液进入离子色谱仪,制取色谱图。根据反应前后硝酸盐氮的变化量,计算出饮用水中余氯的含量。对亚硝酸钠溶液的使用剂量、余氯与生成的硝酸根离子的关系、影响测定的因素进行实验研究。测定出本法的检出限、不确定度和回收率。与国家推荐的标准检验方法实施比较。结果过量的亚硝酸钠完全还原了饮用水中的余氯,NO2-被余氯氧化成了NO3-。NO3-在离子色谱柱上能够进行有效分离,其峰面积的变化与水中余氯的含量呈正相关(r=0.9998),并呈等摩尔关系。根据硝酸盐氮的生成量,能够计算出水中余氯的含量。亚硝酸钠溶液的适宜剂量为1.0ml,本法适合pH≧4.5的反应介质、室温大于5℃的环境。检出限为0.008mg/L,相对标准不确定度为0.68%～5.95%,回收率为94.23%～103.1%。结论本法操作简单、安全,测定的余氯结果准确可靠,可用于测定生活饮用水中余氯的含量。     

饮用水中溴酸盐的离子色谱测定法

目的建立并优化离子色谱法测定饮用水中溴酸盐含量的方法。方法采用大体积进样,离子色谱法梯度淋洗测定饮用水中痕量溴酸盐,并实现饮用水中多种阴离子同时测定。结果该方法对溴酸盐的检出限为0.2μg/L,在1～100μg/L范围内具有良好的线性关系(r=0.999 8),精密度高(RSD<1.0%)样品的加标回收率为95.4%～105.5%,可实现5种阴离子同时测定。结论该方法操作简便、快捷、灵敏度高,适合饮用水日常检测的需要。     

长光程比色-连续流动分析法测定水中挥发酚

目的:建立生活饮用水中挥发酚类化合物的长光程比色连续流动分析方法。方法:采用连续流动分析仪在酸性条件下对样品在线蒸馏,馏出物与碱性铁氰化钾和4-氨基安替吡啉反应生成红色产物,通过LED光源LWCC长光程比色池在505 nm比色测定。结果:在0~10μg/L范围内,标准曲线线性良好(r=0.9998),检出限为0.35μg/L,不同水样中1.0μg/L、2.0μg/L和5.0μg/L的加标回收率为83.00%~108.5%;平行样的相对标准偏差≤5.65%(n=7)。结论:连续流动分析技术操作简单、快速,自动化程度高,测定水中酚时准确度和重复性均好,适合于水中酚的常规分析。     

生活饮用水中4种阴离子的离子色谱测定法

目的建立同时测定饮水中的氟化物、氯化物、硝酸盐氮和硫酸盐的离子色谱测定法。方法依据生活饮用水卫生规范(GB/T 5750-2006)对样品进行测定。3.6 mmol/L的碳酸钠溶液作淋洗液,使用SI-524E色谱柱和SI-90G保护柱进行离子色谱法测定。结果最低检出限分别为F-0.02 mg/L、Cl-0.01 mg/L、NO3-0.006 mg/L、SO42-0.50 mg/L,回收率在98%～103%之间,相关系数均大于0.999。结论该方法灵敏度高,回收率好,操作简便,工作强度低,适合于水质分析中F-、Cl-、NO3-、SO42-这4种阴离子的含量测定。     

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.     

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.