饮用水中3种一氯酚异构体的液相色谱-质谱联用法测定研究

目的:建立一种能同时测定饮用水中2-氯酚、3-氯酚和4-氯酚的检测方法。方法:水样经Oasis(HLB固相萃取小柱富集、净化后,在C8柱(250 mm×4.0 mm×5μm)上,以乙酸-乙酸铵缓冲溶液(5 mmol/L,pH=4.5)/乙腈/甲醇(65:28:7)为流动相,采用大气压化学电离(APC I)离子化方式在选择离子监测(SIM)模式下进行检测,定量检测离子为m/:z 127[M-H]-。结果:2-氯酚、3-氯酚和4-氯酚的日内与日间精密度分别小于9.3%和10.9%,它们在0.05~5.00μg/L范围均具有良好的线性,水样中它们的最低定量检出限分别为0.05、0.02和0.02μg/L。结论:本方法可用于饮用水中痕量一氯酚的测定。     

毛细管气相色谱法测定水中2,4,6-三氯酚和五氯酚

目的:建立测定水中2,4,6-三氯酚和五氯酚的气相色谱测定方法。方法:水中的微量2,4,6-三氯酚和五氯酚经液-液萃取后,用DB-1701毛细管色谱柱,在程序升温条件下进行GC分析,以保留时间定性,外标法定量。结果:2,4,6-三氯酚的线性范围为0.005μg/L~1.0μg/L,最低检出浓度为0.0030μg/L,五氯酚的线性范围为0.01μg/L~2.0μg/L,最低检出浓度为0.0048μg/L,相关系数均≥0.9990,水样加标回收率为73.0%~91.0%,RSD为4.6%~7.9%。结论:方法仅用8.5 m in完成饮用水中2,4,6-三氯酚和五氯酚的测定,操作简便、灵敏度高。     

淋洗液在线发生离子色谱法同时测定饮用水中二氯乙酸、三氯乙酸和草甘膦

目的建立饮用水中二氯乙酸、三氯乙酸和草甘膦的淋洗液在线发生离子色谱测定方法。方法水样经Ion PAC AS19型分析柱(250 mm×4 mm)分离,以KOH为淋洗液,流速为1.00 ml/min,梯度洗脱后抑制型电导检测器检测。结果二氯乙酸、三氯乙酸和草甘膦的线性范围分别为20.0~800μg/L、20.0~800μg/L和20.0~1 000μg/L,相关系数均大于0.999,方法检出限分别为3.2μg/L、3.0μg/L和3.0μg/L,加标回收率为94.0%~110.0%,相对标准偏差为2.49%~6.98%(n=6)。结论本方法操作简便快捷,灵敏度高,结果准确可靠,适用于饮用水中二氯乙酸、三氯乙酸和草甘膦的同时测定。     

高效液相色谱-电喷雾电离质谱联用法测定水中痕量五氯酚研究

目的建立简便、灵敏、准确的测定水中痕量五氯酚的固相萃取-高效液相色谱-质谱联用的检测方法,并用于生活饮用水、渔塘水中痕量五氯酚的污染监测。方法水样经Oasis HLB小柱富集,以甲醇-甲基叔丁基醚(10+90)洗脱,采用甲醇和2mmol/L醋酸铵溶液为流动相进行梯度淋洗,以ZORBAXEclipseXDB-C18柱( 150mm×2 1mm×5μm)分离,通过选择性离子检测(SIM)及电喷雾电离离子化技术进行测定。结果线性范围为5 0μg/L~500 0μg/L,定量检测下限为5 0ng/L,方法回收率在82 8% ~108 5%,RSD均小于10%。结论该法灵敏度高、操作简便、快速,适用于实际样品的测定。     

饮用水中4种氯酚的单液滴微萃取气相色谱-质谱测定方法研究

[目的]研究单液滴微萃取气相色谱-质谱法快速测定饮用水中4种氯酚的最优实验条件。[方法]取50 mL水样,加入内标2,4-二溴酚,经不同条件萃取和衍生后,采用气相色谱-质谱法检测定量。选择单液滴微萃取最佳实验条件,并应用于样本中4种氯酚的测定,再将测定结果与标准方法进行比较。[结果]实验显示最优条件分别为：萃取剂为正己烷-甲苯（1∶1）,衍生剂为N-叔丁基二甲基甲硅烷基-N-甲基三氟乙酰胺（MTBSTFA）,衍生剂比例为20%,搅拌速度为200 r/min,萃取时间为30 min,溶液离子强度为200 g/L的氯化钠溶液。在上述优化的实验条件下,2-氯酚、2,4-二氯酚、2,4,6-三氯酚、五氯酚在0.2~100.0μg/L质量分数范围内,其相关系数分别为0.999 3,0.999 3,0.998 7,0.999 9,检出限分别为0.021、0.018、0.026、0.035μg/L。在1、10、80μg/L三个氯酚水平的平均回收率在85.6%~104.0%,相对标准偏差为2.5%~9.4%。本法测定结果与标准方法比较,无统计学差异。[结论]本研究的优化实验条件下采用单液滴微萃取气相色谱-质谱法步骤简单,快速,与标准方法测定结果一致性高,适用于饮用水中氯酚的快速检测。     

固相萃取-气相色谱法测定饮用水中15种农药残留

目的:建立同时检测饮用水中15种农药残留的固相萃取-气相色谱分析方法,所检测的农药包括5种有机磷、5种有机氯、5种拟除虫菊酯。方法:利用ENVI-C18固相萃取小柱提取水样中农药,小柱用甲醇和水活化,丙酮-正己烷(25:75,v/v)洗脱,浓缩后用GC-ECD测定。对水样前处理和色谱条件等进行了优化选择。结果:有机磷、拟除虫菊酯在0.05~1.0μg/ml,有机氯在0.01~0.2μg/ml浓度范围内有良好的线性,方法检出限为0.0021~0.032μg/L。样品平均加标回收率为70.2%~104.0%,精密度以平行样品的相对标准差(RSD)表示,为2.2%~13.0%。结论:本方法具有操作简单、准确、灵敏、重现性好、安全环保等优点,适用于饮用水中部分拟除虫菊酯、有机氯及有机磷的检测。     

吹扫捕集-气质联用技术测定饮用水中痕量环氧氯丙烷

目的建立测定饮用水中痕量环氧氯丙烷的吹扫捕集-气相色谱/质谱联用检测方法。方法利用吹扫捕集技术,通过对吹扫温度、吹扫时间、解析温度、解析时间等参数进行优化,对水中痕量环氧氯丙烷进行富集、解析,并经DB-624毛细管色谱柱分离,采用选择离子模式(single ion monitoring,SIM)进行检测,提取特征离子定量分析。结果饮用水中环氧氯丙烷在0.122 5~12.25μg/L的浓度范围内线性好,线性相关系数r为0.999 7,本法检出限为0.02μg/L,添加水平为0.122 5~6.125 0μg/L时,测得环氧氯丙烷的加标回收率在91.0%~105.4%,重复测定6次,RSDs为1.7%~5.7%。结论本方法简单、灵敏度高、准确、重现性好,适合饮用水中痕量环氧氯丙烷的测定。     

水中16种半挥发性农药的膜式固相萃取-气相色谱-质谱测定法

目的建立水中16种半挥发性农药的膜式固相萃取-气相色谱(GC)-质谱(MS)测定方法。方法水样(调整pH≤2)经C18固相萃取膜富集,用乙酸乙酯和二氯甲烷洗脱,洗脱液经DryDisk干燥膜,氮吹后定容。DB-35MS毛细管柱分离,采用GC-MS法选择离子扫描模式对水中16种半挥发性农药进行分析,以保留时间和特征离子定性,内标法定量。结果该方法在一定浓度范围(五氯酚:0.1~10.0μg/ml;其余15种半挥发性农药:0.05~5.0μg/ml)内线性关系良好,r≥0.9990;检出限为0.07~0.25μg/L,定量下限为0.21~0.79μg/L,平均回收率为72.8%~126.0%,RSD为3.6%~13.8%。结论该方法有机溶剂用量少,检测种类多,操作简便快速,灵敏度和准确度均较高,适用于饮用水中16种半挥发性农药的测定。     

饮用水中挥发性有机物的吹扫捕集-气相色谱/质谱测定法

目的应用吹扫捕集-气相色谱/质谱联用技术,建立外标法测定饮用水中28种挥发性有机物。方法饮用水中的有机物经氦气吹扫捕集后,被解析到气相色谱中,经过DB-624毛细管色谱柱程序升温分离,质谱选择离子模式测定。结果该方法检出限为0.005～0.15μg/L,最低定量限0.02～0.5μg/L。添加水平为0.5～5.0μg/L时,测定28种挥发性有机物加标回收率为92.4%～108.4%,相对标准偏差为2.73%～8.23%。结论该方法灵敏度高,回收率好,能够快速、准确地检测饮用水中28种挥发性有机物。     

超高效液相色谱-串联质谱法测定饮用水中6种三唑类杀菌剂

目的建立同时检测饮用水中6种(戊菌唑、腈菌唑、三唑醇、氟硅唑、丙环唑和亚胺唑)三唑类杀菌剂的超高效液相色谱串联质谱测定法。方法水样经0.22μm滤膜过滤后,采用超高效液相色谱-串联质谱法分析,在ESI+模式下,多反应监测(MRM)模式检测,通过外标法定量;色谱柱:Waters Acquity UPLC BEH C18(2.1 mm×100 mm,1.7μm);流动相:乙腈-0.15%甲酸溶液。结果线性范围为1μg/L~200μg/L时,所得6种农药的回归方程均呈较好的线性关系,相关系数(r)≥0.999 6,检出限为0.017μg/L~0.035μg/L,定量限为0.058μg/L~0.115μg/L。在2μg/L、10μg/L、100μg/L 3种添加水平下,该方法的平均回收率为89.5%~104.5%,相对标准偏差(RSD)为1.12%~8.51%。结论该方法操作简单、快捷,重现性较好,灵敏度和准确度均能满足同时测定饮用水中多种三唑类杀菌剂的要求。     

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.