3种毛细管色谱柱在水中氯仿和四氯化碳测定中的应用

目的 探讨DB-5、Rtx-1和DB-1毛细管柱在测定饮用水中的氯仿和四氯化碳中应用的可行性.方法 利用氯仿和四氯化碳在水中的弱溶解性,采用静止顶空气相色谱法进行分析,使用DB-5、Rtx-1和DB-1毛细管柱和电子捕获监测器(ECD)测定,外标法定量.结果 用这3种毛细管柱测定氯仿和四氯化碳时,保留时间均小于3 min;氯仿和四氯化碳平均加标回收率分别为92.06%～104.95%,78.33%～103.22%;氯仿和四氯化碳的RSD分别为2.06%～2.71%,1.76%～5.59%.结论 这3种毛细管柱均可以满足测定要求.     

顶空气相色谱法测定饮用水中氯仿及四氯化碳

本文介绍了用顶空气相色谱法测定饮用水中氯仿及四氯化碳。观察了水浴温度、时间及顶空气体体积对测定结果的影响,选择了适当的空白,使测定方法更加简便。本法的最低检出浓度氯仿为0.2μg/L、四氯化碳为0.04μg/L,变异系数氯仿在10%以内、四氯化碳在20%以内,回收率均在84～105%之间。实验结果表明采用本法测定饮用水中氯仿及四氯化碳的含量,分离效果好,分析周期短,精密度和回收率比较理想,是一种快速、准确、可靠的测定方法。     

饮用水中三氯甲烷和四氯化碳的气相色谱测定法

目的建立测定饮用水中三氯甲烷和四氯化碳含量毛细管气相色谱法。方法采用DB-5毛细管柱和电子捕获检测器测定,外标法定量。结果样品加标回收率三氯甲烷为95.07%~104.80%,四氯化碳为89.94%~96.17%,相对标准偏差(RSD)小于2.06%。结论该方法简便、快速,适合饮用水中氯仿和四氯化碳含量的测定。     

顶空色谱法测定塑料管材管件中有害物质研究

目的　研究顶空色谱法检测塑料管材、管件中氯仿、四氯化碳的效果 ,期望建立方便、快捷、准确地检测塑料管材、管件中有害成分的方法。方法　采用顶空色谱法 ,以电子捕获检测器、DC - 5 5 0色谱柱 ,气化室温度 1 5 0℃、检测器温度 1 80℃、柱温 85℃为检测条件对样品检测、分析。结果　氯仿在 0～ 80ug/L、四氯化碳在 0～ 8.0ug/L范围内呈良好的线性关系 (r =0 .99998;r =0 .9984 ) ;方法的最低检测质量浓度为 :氯仿0 .6ug/L、四氯化碳 0 .3ug/L ;方法的回收率氯仿 95 .4 %～ 1 0 2 .3% ;四氯化碳为 97.3%～ 1 0 2 % ,3种浓度的相对偏差 :氯仿 2 .4 %、2 .5 %、0 .88% ,四氯化碳 6 .2 5 %、7.1 0 %、0 .85 %。结论　本法具有干扰小、灵敏度高、操作简便、快捷 ,结果准确、可靠的优点 ,适合于各种涉水产品中氯仿、四氯化碳的测定     

水中三氯甲烷、四氯化碳的QHSS-40自动进样顶空气相色谱测定法

目的建立测定水中三氯甲烷和四氯化碳含量的全自动顶空气相色谱法。方法利用全自动顶空进样技术,采用ECD检测器测定水中三氯甲烷和四氯化碳。结果在测定条件下,方法的检出限三氯甲烷为0.06μg/L,四氯化碳为0.03μg/L;三氯甲烷的RSD为1.7%～2.5%,四氯化碳的RSD为1.5～2.8%;回收率三氯甲烷为101%～103%,四氯化碳为99.6%～102%。结论该方法简便、快速、具有较好的精密度与准确度,适用于水中三氯甲烷、四氯化碳测定。     

核酸提取方法对乙肝病毒定量PCR检测结果的影响

目的寻找简单、快速地提取血清乙型肝炎病毒(HBV)DNA并能应用于定量PCR测定的方法. 方法使用碱裂解法、酚氯仿法和煮沸裂解法同时提取血清HBV-DNA,比较荧光定量PCR测定的重复性和测定值的差异. 结果碱裂解法所得HBV-DNA量高于酚氯仿法和煮沸裂解法(P＜0.05),并且碱裂解法所得结果的重复性好于酚氯仿法和煮沸裂解法(CV分别为0.21,0.28和0.33). 结论碱裂解法提取HBV-DNA简单、快速,适用于HBV-DNA荧光定量测定.     

农残Ⅰ号毛细管柱测定水中氯仿四氯化碳探讨

生活饮用水中氯仿、四氯化碳的测定，一般采用玻璃填充柱顶空气相色谱法测定。农残Ⅰ号是兰州化学物理研究所为测定农药残留而定制的毛细管色谱专用柱，本实验室用来测定有机氯和拟除虫菊酯农药残留，而测定水中氯仿、四氯化碳时得换成中极性的玻璃填充柱，不仅麻烦，还容易折断玻璃柱。为此对用农残Ⅰ号测定饮用水中氯仿四氯化碳进行了摸索，发现在一定的条件下，可用来测定饮用水中氯仿、四氯化碳，避免了频繁换色谱柱的麻烦。现报告如下：     

毛细管气相色谱法测定大白鼠肝细胞中四氯化碳

用非极性毛细管气相色谱法分离测定大白鼠肝细胞中四氯化碳,以乙作萃取溶剂。方法的线性范围宽(0.1mmol/L～0.01μmol/L),灵敏度高(最低检测浓度为5×10~(-3)nmol/L),于样品中加不同量四氯化碳的回收率为98.5～111.0%,精密度实验 CV 为7.6%。同一条件下还可分离出四氯化碳在肝细胞中代谢的痕量产物氯仿。本方法简便、快速、可靠。     

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。     

饮用水中氯仿和四氯化碳的顶空固相微萃取气相色谱测定法

目的建立饮用水中氯仿(CHCl3)和四氯化碳(CCl4)的顶空固相微萃取(HS-SPME)-气相色谱(GC)分析方法。方法样品经顶空固相微萃取后,进行毛细管柱气相色谱分析,优化后的分析条件为二乙烯基苯-碳分子筛-聚二甲基硅氧烷(DVB-CAR-PDMS,膜厚50μm)萃取头,吸附平衡时间为10min,解吸时间为3min,水浴温度为40℃,水浴平衡时间为60min。气化室温度为220℃,柱箱温度为40℃,检测器(ECD)温度为260℃,载气(氮气,N2)柱流量为3.5ml/min。结果氯仿的线性范围在1～10μg/L之间,所得回归方程为y=32567x-4489.3,相关系数为0.9997,检出限为0.024μg/L;四氯化碳的线性范围在0.1～1.0μg/L之间,所得回归方程为y=197521x-4096.4,相关系数为0.9995,检出限为0.0042μg/L。该方法所得的平均回收率为94.2%～108.0%,RSD为0.6%～2.4%。采用HS-SPME-GC法和国标法测定氯仿和四氯化碳的混合溶液,结果间差异无统计学意义。结论该方法具有操作简便,灵敏度高,结果准确的优点,适用于饮用水中氯仿和四氯化碳的测定。     

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.