顶空气相色谱法测定饮用水中的三氯甲烷及四氯化碳

目的 建立同时测定生活饮用水中三氯甲烷、四氯化碳含量的顶空毛细管柱气相色谱方法.方法 采用顶空自动进样技术,用毛细管柱气相色谱法测定饮用水中微量的三氯甲烷、四氯化碳含量.以保留时间定性,峰面积外标法定量.结果 该方法实现了两种消毒副产物的同时分析测定,灵敏度高、线性范围宽、检出限低,三氯甲烷在0～72.0μg/L浓度范...     

饮用水中三氯甲烷和四氯化碳的顶空气相色谱测定法

目的建立测定饮用水中了氯甲烷和四氯化碳含量的顶空毛细管柱气相色谱法,同时考察不同来源饮用水中氯仿和四氯化碳的分布状况、方法采用顶空自动进样技术,用特异性DB-624毛细管柱气相色谱法测定水中三氯甲烷和四氧化碳。结果标准曲线的相关系数为〉0.999,相对标准偏差为1.5％-8.3％,三氯甲烷、四氯化碳的平均回收率为97.5％-103.3％;三氯甲烷的线性范围为2.0-10.0μg／L,检出限为0.02μg／L;四氯化碳线性范同为1.0-5.0μg／L,检出限为0.003μg／L。结论该方法简便、快速,具有较好的精密度与准确度,可用于水中三氯甲烷、四氯化碳的测定。     

气相色谱法测定饮用水中挥发性卤代烃的不确定度评定

目的建立自动顶空毛细柱气相色谱法测定饮用水中三氯甲烷、四氯化碳、二氯一溴甲烷、一氯二溴甲烷、三溴甲烷等挥发性卤代烃的不确定度评定方法,以评定测量结果的质量。方法根据GB／T5750．8—2006（（生活饮用水标准检验方法》建立数学模型,逐一分析量化测量过程中的不确定度分量,计算合成标准不确定度和扩展不确定度。结果三氯甲烷含量为5．88μg／L时,U=0．42μg/WL,k=2;四氯化碳含量为1．98μg/L时,U=0．18μg/E,％=2;二氯一溴甲烷含量为12．60μg/L时,U=0．72μg/WE,k=2;一氯二溴甲烷含量为6．00μg/WL时,U：0．36μg/L,k=2;三溴甲烷含量为5．55μg／L时,U=0．38μg/WE,％=2。结论曲线拟合和标准溶液带来的不确定度是测量结果不确定度的主要来源,此方法适用于饮用水中挥发性卤代烃的不确定度评定。     

气相色谱法同时测定水中三卤甲烷、四氯化碳的运用研究

目的：建立水中测定三卤甲烷和四氯化碳含量的顶空毛细管柱气相色谱法,并观察水样中三卤甲烷和四氯化碳各自的分布状况,测出检测限值和三卤甲烷、四氯化碳的平均回收率。方法：参照国内顶空进样标准,采用顶空毛细管柱气相色谱法测定水中三卤甲烷和四氯化碳。结果：标准曲线相关系数范围大于0.999,相对标准偏差介于1.6%~8.2%之间,三卤甲烷的线性范围为2.0μg/L~10.0μg/L,四氯化碳的线性范围为1.0%μg/L~5.0μg/L,两者的检出限分别为0.02μg/L和0.003μg/L,平均回收率为97.5%~104.2%。结论：使用顶空毛细管柱气相色谱法测定水中的三卤甲烷和四氯化碳方便而快捷,结果准确,可靠性佳。     

顶空串联气相色谱法检测水中三氯甲烷、四氯化碳

运用气相色谱法对城市自来水中的三氯甲烷、四氯化碳进行检测，进样采用方式为顶空自动进样。改进了顶空进样条件中的平衡温度和时间、气相色谱的柱温和分流比四个因素。结果显示三氯甲烷的浓度在10.0～100.0μg/L、四氯化碳0.5～5.0μg/L时，标准曲线的线性满足使用要求，相关系数先后为0.9987、0.9999,检出限分别为0.06μg/L及0.01μg/L,RSD为4.59%及10.60%,相对误差为2.13%及8.36%。方法操作简单快速，更适合水样的批量检测。     

顶空固相微萃取-气相色谱法测定环境中挥发性有机物

目的：建立顶容固相微萃取－气相色谱法同时测定环境样品中苯系物，氯代甲烷类等挥发性有机物的方法。方法：采用未涂任何固定液的光纤作为萃取头，自行制作的固相微萃取SPME装置，通过顶空固相微萃取气相色谱法（HS－SPME－GC）测定氯代甲烷和苯系物，并对测定的萃取条件和色谱条件进行了优化，结果：方法的线性范围为二氯甲烷0．14－75．7μg/L,三氯甲烷0．24－84．5μg/L，四氯化碳0．45－137．1μg/L，苯0．03－12．6μg/L，甲苯0．10－24．8μg/L ，乙苯0．06－24．7μg/L，二甲苯0．13－24．8μg/L，相关系数为0．9914－0．9979，检出限为二氯甲烷0．14μg/L,三氯甲烷0．24μg/L ，四氯化碳0．45，苯0．03，甲苯0．10μg/L，乙苯0．06μg/L，二甲苯0．13μg/L，样品加标回收率为80．0％－111．6％，相对标准偏差为4．4％－8．1％，结论：该法简便，快速，灵敏度高，重现性好，分析成本低。     

顶空气相色谱法测定水中三氯甲烷和四氯化碳

目前，测定饮用水中三氯甲烷和四氯化碳的国标方法采用的是填充柱气相色谱法，检测器是电子捕获检测器(ECD)。该法的检测限较高，三氯甲烷为10μg/L，四氯化碳为1μg/L，有时不能满足饮用水中这两种物质分析灵敏度的要求。目前毛细管柱的商品化已日趋完善，且分离效果和使用寿命均高于填充柱。本实验通过利用灵敏度高于普通ECD检测器的μ-ECD(微池电子捕获检测器)作为检测器，     

自动顶空毛细管柱气相色谱法测定生活饮用水中的5种卤代烷烃

目的建立同时测定生活饮用水中5种卤代烷烃的自动顶空毛细管柱气相色谱法。方法准确吸取2 ml水样于顶空瓶中,顶空装置自动进样,毛细管柱分离,GC-ECD进行检测。结果水样中5种卤代烷烃均在14 min内完成检测,线性范围分别为:三氯甲烷:0μg/L~4.24μg/L;四氯化碳:0μg/L~1.2μg/L;一氯二溴甲烷:0μg/L~5.24μg/L;二氯一溴甲烷:0μg/L~3.72μg/L;三溴甲烷:0μg/L~12.36μg/L;相关系数r0.999,检出限为0.065μg/L~0.51μg/L;两组混标样的添加回收率均为94.4%~105.6%,相对标准偏差(RSD)均5%。气相色谱柱温条件:初始柱温为60℃,保持5 min,之后以10℃/min升温至85℃,保持7 min。顶空进样装置保温时间为15 min。结论该方法具有简便快速、检出限较低、线性关系较好、回收率高等特点,适用于生活饮用水中三氯甲烷、四氯化碳、一氯二溴甲烷、二氯一溴甲烷和三溴甲烷的检测分析。     

水中氯仿及四氯化碳的顶空固相微萃取测定法

目的：提高分析水中微量氯仿，四氯化碳的效率和方法的灵敏度。方法：采用顶空固相微萃取法代替传统的顶空法测定水中微量的氯仿，四氯化碳，结果：方法最低检出限分别为0．05μg/L和0．005μg/L，准确度和精密度均符合检测的要求。结论：顶空固相微萃取法测定水中微量的氯仿，四氯化碳，操作简单快捷，且灵敏度高于顶空法。     

毛细柱——微电子捕获气相色谱法测定水中氯仿、四氯化碳

毛细柱－微电子捕获气相色谱法水中氯仿，四氯化碳，其线性范围得到扩延，氯仿浓度在0－10μg/L范围内，相关系数r=0.9910，回归方程Y＝1．959X＋4．816，最低检出学为0．1032μg/L，四氯化碳浓度在0－1μg/L，范围内，相关系数r=0.9970，回归方程Y＝3．947X＋42．579，最低检出浓度为0．01219μg/L。同时，本方法简化了操作过程，方法灵敏度得到较大提高，并且准确度和精密度均符合检测要求。     

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.