氢化物原子荧光法与石墨炉原子吸收法测定微量镉

目的：在镉的测定方面比较不同仪器的性能。方法：氢化物原子荧光法和石墨炉原子吸收法。结果：氢化物原子荧光法和石墨炉原子吸收法的检出限为5.81 ng/L和3.78 ng/L,相对标准偏差为1.31%和4.12%,回收率为94.0%～106.0%和95.5%～104.5%。结论：在微量镉的测定方面,氢化物原子荧光法是一种比较好的方法。     

性保健品中铅镉砷汞残留量测定方法研究

目的：应用微波消解前处理研究分析性保健品中铅、镉、砷、汞残留量的方法。研究了微波消解条件对分析结果的影响,同时分析了FAAS测定的最佳条件及石墨炉法测定铅、镉的基体改进剂的选择。方法：用微波消解系统对性保健品进行消解,消解过的样液用石墨炉原子吸收光谱仪和原子荧光光谱仪分别测定性保健品中的铅、镉、砷、汞的残留量。结果：本方法测定铅、镉、砷、汞的检出限分别为0.30、0.026、0.086和0.011μg/L。平均回收率分别为98.5%、99.3%、100.4%和96.9%。测定线性范围分别为0-80.0μg/L、0-8.0μg/L、0-80μg/L和0-8.0μg/L。结论：本方法简便快速,灵敏度、精密度、准确度较好,适合性保健品的快速消解及微量金属污染物的定量分析。     

石墨炉原子吸收法直接测定酱油中的铅

目的：建立一种石墨炉原子吸收法直接测定酱油中铅的方法。方法：以氯化钯和硝酸铵为基体改进剂,酱油样品经稀释后直接用石墨炉原子吸收法测定。结果：氯化钯和硝酸铵基体改进剂的使用,可将灰化温度提高到1 000℃,降低氯化钠对测定结果的影响。线性范围为0～80μg/L,相关系数在0.9980以上,方法的检出限为1.7μg/kg,定量限为5.6μg/kg,测定样品的相对标准偏差在1.5%～3.3%之间,回收率在89.5%～108.0%之间。结论：采用氯化钯和硝酸铵为基体改进剂,用石墨炉原子吸收法直接测定酱油中的铅,是测定酱油中铅的一种简便、快速、准确的方法。     

石墨炉原子吸收法直接测定尿液样品中铅的浓度探讨

目的探讨石墨炉原子吸收法在尿液铅浓度测定中的应用情况及注意事项。方法以0.66g/L氯化钯（优级纯）为基体改进剂,利用氘灯扣除背景,使用石墨炉原子吸收光谱法直接检测尿液铅浓度。结果石墨炉原子吸收法线性范围为2-120μg/L,其相关系数为0.9990、检出限为2.0μg/L。结论石墨炉原子吸收法中背景对结果的干扰非常小,稳定性好,检测结果准确,操作简单,尤其适合大批量样液的检测,值得推广使用。     

同时测定保健食品中微量铅和汞的方法研究

目的：建立一种快速消解并同时测定保健食品中微量铅和汞的方法。方法：采用微波消解样品，氢化物发生原子吸收光谱法同时测定保健食品中的微量铅和汞。结果：方法简便、快速、准确，灵敏度高，方法检出限铅和汞分别为0．10μg/L、0．35μg/L，平均加收率铅和汞分别为94．2％、103．9％，对铅含量为10．0μg/L，汞含量为10．0μg/L的样品连续测定8次的相对标准偏差分别为2．29％、3．61％。结论：保健食品中的微量铅和汞可以用氢化物原子吸收法同时测定。     

水中痕量镉的氢化物发生原子荧光光谱测定法

目的建立水中痕量镉的氢化物发生原子荧光光谱测定方法。方法采用氢化物发生原子荧光光谱法对水中痕量镉进行测定,进行共存元素离子的干扰试验,并将该方法与石墨炉原子吸收法进行比较。结果在最佳测量条件下,当镉含量在0.03－10μg/L的范围内,其回归方程为y=174.05x＋4.75,r=0.9992,该方法的检出限为0.03μg/L,RSD为1.1%－3.0%,回收率为98.2%－107.0%。结论该方法具有快速、准确、灵敏度高、精密度好等优点,用于水中镉含量的测定,结果令人满意。     

石墨炉原子吸收光谱法测定食品中的铅

食品中铅的测定有石墨炉原子吸收法、氢化物原子荧光法、火焰原子吸收法、二硫腙比色法。目前, 应用较多的是石墨炉原子吸收法,但其重现性稍差, 为提高其重现性,本文对铅的石墨炉原子吸收法的测定条件及影响因素进行探讨,加入基体改进剂,减少了干法灰化和湿法消化处理样品对铅测定的影响,使仪器的测定达到准确、快速的目的。一、材料与方法 1．试剂铅标准溶液(1．0mg/mL),铅标准使用液(10．0ng/mL),硝酸(优级纯)、高氯酸(优级纯)、磷     

石墨炉原子吸收法测定尿中的铅

目的建立一种直接稀释-石墨炉原子吸收法测定人体尿液中铅含量的方法。方法用硝酸酸化尿样,加入2g/L的氯化钯为基体改进剂直接进行石墨炉原子吸收光谱测定。结果方法的线性范围为0-80μg/L,相关系数0.9996,RSD为1.8%-3.6%,回收率91.0%-105.0%,方法检出限1.1μg/L。结论该方法精密度、准确度、稳定性好,能很好地满足尿中铅含量的测定要求。     

石墨炉原子吸收法测尿铅检出限的测量结果不确定度

目的探讨石墨炉原子吸收法测尿铅检出限误差性质和来源,建立测定尿铅检出限不确定度的评定方法。方法依据JJF1059—1999（（测量不确定度评定与表示》原理和方法计算石墨炉原子吸收法测定尿铅检出限的合成标准不确定度。结果石墨炉原子吸收分光光度法测定尿铅的检出限为0．35μg／L,检出限范围为0．190～0．510μg/L。结论尿铅测定方法的检出限经不确定度的评定,完全满足实际工作中尿铅测定的相关标准（参考值）及方法学中灵敏度要求。     

石墨炉原子吸收法直接测定碳酸及茶饮料中的铅

目的去除繁琐的样品前处理,探讨一种更加快速环保的样品测定方法,使得石墨炉原子吸收法能够直接测定茶饮料及碳酸饮料中铅。方法以钼酸铵为基体改进剂,优化石墨炉测定程序,样品直接进样或经稀释后进样,用石墨炉原子吸收法测定。结果采用改进后的方法获得的工作曲线浓度-吸光度相关系数r为0. 999 5,线性范围为0μg/L～80μg/L,方法检出限为0. 18μg/L,低、中、高3个浓度重复性实验的相对标准偏差为2. 22%～3. 77%,回收率为93. 9%～102. 7%。工作曲线线性、精密度、准确度等效果良好。此法无需消解样品,采用的钼酸铵价格便宜,节约了大量的时间和成本。结论采用钼酸铵作为基体改进剂,用石墨炉原子吸收法直接测定茶饮料及碳酸饮料中铅的含量,是测定饮料中铅的一种简便、快速、准确的方法。     

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.     

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.     

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.     

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.     

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.     

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.     

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.