顶空气相色谱法测定空气中亚硝酸盐

目的:建立空气中亚硝酸盐的顶空气相色谱测定方法。方法:采用超细玻璃纤维滤纸采集空气中亚硝酸盐,用蒸馏水洗脱过滤后,经酯化后,采用顶空法进样技术,经色谱柱分离,FID检测器检测,保留时间定性,峰高或峰面积定量。结果:空气中亚硝酸盐线性范围0.56~20μg/m l;相关系数r=0.9998;方法最低检出限0.56μg/m l;若采集300 L空气进行测定,最低检出浓度为0.019 mg/m3;样品的平均回收率为95.2%~99.1%;相对标准偏差是0.77%~2.74%;样品洗脱效率为98.8%~99.5%;采样效率93.4%~97.2%;样品在室温至少可保存1周。结论:该方法操作简便,灵敏度高,选择性好,干扰少,线性范围宽,检测限低,是测定空气中亚硝酸盐的理想检测方法。     

顶空气相色谱测定空气中氟化物方法的研究

目的:建立一种顶空气相色谱测定空气中氟化物的方法。方法:采用浸泽超细玻璃纤维滤纸采集空气中氟化物,用蒸馏水洗脱过滤后,采用顶空法进样技术,经色谱柱分离,FID检测器检测,保留时间定性,峰高或峰面积定量。结果:空气中氟化物线性范围0.5μg/ml～30.0μg/ml;相关系数r=0.9997;方法最低检出限0.5μg/ml;若采集75 L空气进行测定,最低检出浓度为0.018 mg/m3;平均回收率为95.4%～99.7%;相对标准偏差是0.7%～2.6%;样品洗脱效率为99.0%～99.8%;采样效率93.48%～96.32%;样品在室温至少可保存1周。结论:该方法操作简便,灵敏度高,选择性好,干扰少,线性范围宽,检测限低,是测定空气中氟化物的理想检测方法。     

热解吸气相色谱法测定工作场所空气中乙酸甲酯和乙酸乙酯

目的:建立工作场所空气中乙酸甲酯、乙酸乙酯热解吸气相色谱法测定方法。方法:活性炭采集空气中的乙酸甲酯及乙酸乙酯,在300℃用高纯氮解吸,在FFAP毛细管色谱柱上分离(FID)测定。结果:空气浓度在0~900 mg/m3时,回归方程为:乙酸甲酯Y=630139X-2431,r=0.9996;乙酸乙酯Y=553933X+1686,r=0.9998。最低检出限为:乙酸甲酯7.8×10-4μg/m l,乙酸乙酯9.0×10-4μg/m l;最低检出浓度(采集1.5 L空气样品)分别为:0.052 mg/m3和0.060 mg/m3;相对标准偏差(RSD):乙酸甲酯3.3%~6.6%,乙酸乙酯3.9%~5.7%;平均解吸效率为乙酸甲酯94.3%,乙酸乙酯91.8%;常温下样品至少可稳定7 d。结论:本方法适用于工作场所空气中乙酸甲酯和乙酸乙酯测定。     

工作场所空气中四溴化碳吸收液采样气相色谱测定方法的研究

目的:建立工作场所空气中四溴化碳吸收液采样气相色谱测定方法。方法:选用无水乙醇作吸收液采集空气中四溴化碳,以毛细管气相色谱(ECD)测定。结果:空气中四溴化碳浓度在0~20 mg/m3(以采集3 L空气样品计,相当于10 ml无水乙醇吸收液采样管中四溴化碳溶液浓度0~6μg/ml)时,线性关系良好(r=0.9997,n=3),回归方程Y=35520.3X-2966.5;方法的检出限为0.086μg/ml(进样1μl,3倍噪声所相当的量);最低检出浓度为0.29 mg/m3(以采集3.0 L空气样品计);相对标准偏差在0.4%~4.0%之间;采样效率92.7%;四溴化碳乙醇溶液封闭严密,4℃冰箱保存6 d稳定。结论:本方法适用于工作场所空气中四溴化碳的浓度测定。     

气相色谱法测定工作场所空气中的乳酸正丁酯

目的:建立工作场所空气中乳酸正丁酯溶剂解吸气相色谱测定方法。方法:活性炭采集空气中的乳酸正丁酯,用二氯甲烷 甲醇(95 5)溶剂解吸,采用气相色谱法在FFAP色谱柱上分离,FID检测器测定。结果:空气浓度在0~1960 mg/m3时,回归方程为Y=240904X 5728118,r=0.9992;最低检出限为1.6×10-4μg/ml(进样1.0μl),最低检出浓度为0.05 mg/m3(以采集3.0 L空气样品计);相对标准偏差(RSD)为1.2%~76%,平均解吸效率为97.3%;室温下样品至少可保存14 d。结论:本方法适用于工作场所空气中乳酸正丁酯浓度的测定。     

工作场所空气中磷酸的采集及测定

目的建立工作场所空气中磷酸的采集及离子色谱测定方法。方法采用超细玻璃纤维滤膜采集样品,用超纯水超声洗脱,经0.22μm滤膜过滤后直接进样,经阴离子色谱柱分离,电导检测器进行测定。结果该方法在1.4~60μg/ml范围内呈线性关系,相关系数为0.999 7,定量下限为1.4μg/ml,最低定量浓度为0.2 mg/m~3(以采样75 L计),精密度为1.9%~4.2%,平均回收率为99.9%,平均采样效率为100.0%,平均洗脱效率为95.2%。结论方法采样效率高,最低检出浓度低,准确度和精密度高,能满足工作场所空气中磷酸的采集及检测要求。     

工作场所空气中邻苯二甲酸酐测定方法的研究

空气中邻苯二甲酸酐用玻璃纤维滤纸采集,随即放入预先装有2 ml丙酮的样品瓶中,盖塞,摇匀后用DB-1毛细管柱气相色谱(FID)测定。邻苯二甲酸酐浓度在0~200μg/ml范围内线性关系良好,线性方程y=8.9+12.6x(r=0.999 9。检出限为0.39μg/ml,若采集30 L空气样品,则最低检出浓度分别为0.026 mg/m3,平均加标回收率99.7%~101.4%,相对标准偏差在1.2%~3.7%。本方法适用于工作场所空气中邻苯二甲酸酐浓度的测定。     

毛细管色谱柱气相色谱法测定工作场所空气中三乙胺

目的建立优化使用毛细管色谱柱溶剂解析气相色谱法测定工作场所空气中三乙胺的方法研究。方法采用碱性硅胶管采集工作场所中的三乙胺,加入硫酸与氢氧化钠解析,使用HP-5色谱柱分离,FID测定。结果该方法三乙胺检出限为0.5μg/ml,线性范围为0.5~1 340.0μg/ml,最低检出浓度为0.13 mg/m3(以采集7.5 L空气样品计);相对标准偏差为0.63%~3.31%,解析效率为99.5%~100.6%,加标回收率为98.2%~101.8%,样品在室温下至少可保存7 d。结论该方法适用于工作场所空气中三乙胺的测定。     

超声萃取反相离子对高效液相色谱法测定食品中亚硝酸盐和硝酸盐含量

目的:建立应用超声萃取反相离子对高效液相色谱法测定食品中亚硝酸盐和硝酸盐含量的方法。方法:食品样品经温水浴,超声萃取,去脂肪和沉淀蛋白后,进样20μl,以甲醇-混合磷酸盐(1.25 mmol/L Na2HPO4和1.25 mmol/LKH2PO4及内含4 mmol/L四丁基溴化铵)(体积比为20:80)为流动相,流速为1.0 ml/min,经GeminiTMC18色谱柱(250×4.6 mm,5μm)柱分离,225 nm检测。结果:亚硝酸盐、硝酸盐完全分离,R>1.5,在0.20~100.00 mg/L范围内成线性,相关系数大于0.9995,检出下限分别为0.08,0.10 mg/L,回收率在97.4%~101.9%之间。结论:该方法准确、灵敏,操作简便,同时测定硝酸盐和亚硝酸盐,适合于食品样品中硝酸盐和亚硝酸盐的测定。     

饮料中6种添加剂超高效液相色谱测定

目的:建立饮料中6种食品添加剂的超高效液相色谱同时测定方法。方法:样品经乙腈去除蛋白后用水稀释,采用C18色谱柱,以乙酸铵缓冲液(0.02 mol/L)/甲醇为流动相,采用梯度洗脱分离,在230 nm波长下进行检测。结果:6种食品添加剂的加标回收率在90%~108%之间,相对标准偏差在1.0%~3.8%之间。阿斯巴甜在15μg/m l~100μg/m l范围具有良好的线性,安赛蜜、苯甲酸、山梨酸、糖精钠和咖啡因在1μg/m l~10μg/m l范围具有良好的线性,回归系数均大于0.999,最低定量限分别为,安赛蜜0.05 mg/L,苯甲酸0.05 mg/L,山梨酸0.02 mg/L,糖精钠0.1 mg/L,咖啡因0.1 mg/L,阿斯巴甜1.0 mg/L。结论:本方法简便、灵敏、重现性好,能满足饮料中6中添加剂的测定要求。     

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.     

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.