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。     

饮用水中多种有机磷农药残留的气相色谱-三重四极杆质谱测定法

目的建立一种同时测定饮用水中7种有机磷农药残留量的气相色谱-三重四极杆质谱（GC-MS/MS）方法。方法采用液-液萃取方法,用二氯甲烷对水样中7种有机磷农药进行提取,无水硫酸钠脱水,滤液在40℃水浴中旋转蒸发近干,用二氯甲烷定容,GC-MS/MS测定,外标法定量。结果 7种有机磷农药在21 min内分离,在0.01-10 mg/L范围内相关系数r2均在0.99以上,在0.05、0.25和0.45 mg/L 3个水平加标回收率在78.9%-99.3%之间,相对标准偏差均小于10%,检出限为0.02-0.06μg/L。结论该方法操作简单,准确度和精密度高,消除了其他有机磷农药的干扰,避免假阳性的出现,适用于饮用水中7种有机磷农药残留量的检测和确证。     

QuEChERS-气相色谱法测定尿中的19种有机磷农药

目的建立测定尿中19种有机磷农药的QuEChERS-气相色谱法。方法以DB-5毛细管柱为分析柱,用QuEChERS-气相色谱法,同时测定尿中19种有机磷农药。结果按设定的气相色谱条件,19种有机磷农药在质量浓度0~0.4μg/mL范围内线性良好,相关系数r为0.997 2~1.000,检出限在0.005~0.012μg/mL,相对偏差(RSD)2.6%~7.2%,除甲胺磷、乙酰甲胺磷、氧乐果3种有机磷农药回收率在48.7%~62.9%,其他16种有机磷农药在91.3%~117.2%。结论建立的QuEChERS-气相色谱法能够同时测定尿中19种有机磷农药。     

气相色谱法测定水中7种有机磷农药

目的:建立饮用水中7种有机磷农药的检测方法。方法:水中微量有机磷农药经二氯甲烷萃取,用无水硫酸钠脱水,定量注入色谱仪(FPD)可定量测定敌敌畏,内吸磷,乐果,甲基对硫磷,马拉硫磷,毒死蜱和对硫磷。结果:在所建立的条件下平均回收率在86%~110%之间,相对标准差(RSD)为1.97%~4.72%,检测限为0.001~0.0042 mg/L。结论:所建立的分析方法简便、快速、准确,可同时测定7种有机磷农药。     

毛细管气相色谱法同时检测农产品中17种农药残留的研究

目的:建立了同时测定农产品中17种农药残留的毛细管气相色谱分析方法。方法:采用乙腈提取,经氯化钠盐析分层,取有机相净化处理后注入气相色谱仪,以毛细管柱分离-氮磷检测器检测,外标法定量。结果:17种农药的线性范围为0μg/m l~5.0μg/m l,标准曲线的相关系数范围为0.99~1.00,相对标准偏差(RSD)为0.97%~6.22%,平均加标回收率为67.1%~103.4%,检测限为0.01 mg/kg~0.06 mg/kg。结论:本文建立同时测定农产品中17种有机磷农药的气相色谱分析方法,该法简便、快速、灵敏。适用于蔬菜水果食用菌等农产品中农药残留的测定。     

饮用水中12种有机磷及氨基甲酸酯类农药残留量的气相色谱-质谱测定法

目的建立饮用水中12种有机磷及氨基甲酸酯类农药残留量的气相色谱-质谱测定法。方法以二氯甲烷-石油醚(体积比为4∶1)为萃取剂进行萃取,采用气相色谱-质谱法同时测定了饮用水中12种有机磷和氨基甲酸酯类农药的含量。结果在0.01～1.0μg/ml内,12种农药的回归方程线性关系良好,相关系数均>0.997,平均回收率为76.0%～111.0%,RSD为5.20%～9.20%,以3倍信噪比计算检出限,敌敌畏、异丙威、灭害威、抗蚜威、马拉硫磷、禾草丹、倍硫磷、对硫磷、溴硫磷、除草通、灭螨蜢、三硫磷的检出限分别为0.009、0.003、0.008、0.001、0.003、0.003、0.0025、0.009、0.005、0.010、0.010、0.006μg/ml。结论该方法简便、快捷,结果准确,灵敏度高,适用于饮用水中12种有机磷和氨基甲酸酯类农药残留量的同时检测。     

饮用水中6种有机磷农药的自动固相萃取-气相色谱测定法

目的建立饮用水中6种有机磷农药的固相萃取气相色谱分析方法。方法采用C18柱对水样进行固相萃取后,使用气相色谱-火焰光度检测器测定水中6种有机磷农药。结果 6种有机磷农药的方法检出限均低于0.000 3mg/L。加标回收率为83.3%~103.2%,RSD均小于7.9%。结论方法操作简便、快速、灵敏,有机溶剂用量少,环境污染小,适用于饮用水中6种有机磷农药的同时测定。     

液液萃取-气相色谱质谱法测定饮用水中19种有机磷农药

目的:建立测定饮用水中19种有机磷农药(治螟磷,甲拌磷,内吸磷,二嗪磷,乙拌磷,异稻瘟净,氧化乐果,甲基对硫磷,皮蝇磷,甲基嘧啶磷,杀螟硫磷,马拉硫磷,毒死蜱,倍硫磷,对硫磷,久效磷,溴硫磷,甲基异柳磷,稻丰散)液液萃取-气相色谱质谱(GC-MS)检测方法。方法:二氯甲烷液液萃取(LLE)水样后,浓缩提取液至1 ml后,采用气相色谱-质谱(GC-MS)的选择离子监测(SIM)模式同时定性定量分析。结果:19种有机磷农药的峰面积与其浓度均有良好的线性关系,相关系数均大于0.998;最小检测量为0.14μg/L～0.64μg/L;样品加标回收率为85.2%～97.9%,相对标准偏差为1.9%～9.8%。结论:该方法可对饮用水中有机磷农药同时定量与定性,具有方法简便、准确、可靠等优点。     

离子色谱法同时分析水中酸性除草剂灭草松和2,4-滴

目的:建立离子色谱法对饮用水中2,4-滴和灭草松酸性除草剂进行同时检测。方法:以AS19柱分离,30 mmol/L KOH为淋洗液、流速为1.2 ml/min、进样量500μl,电导检测。结果:二种除草剂分别在30~1000μg/L和100~1000μg/L的线性范围内呈良好的线性关系,加标回收率为95.4%~104.1%,相对标准偏差为1.08%~2.04%(n=6),方法检测限分别为10μg/L和30μg/L,能达到国家有关上述除草剂残留限量的要求。结论:本法操作简便,准确可靠。     

蔬菜中多种有机磷农药残留的固相萃取-气相色谱测定方法研究

目的建立同时测定蔬菜中多种常见有机磷农药残留的固相萃取-气相色谱法。方法样品经乙腈提取、固相小柱净化,气相色谱法进行测定。结果在优化的条件下,多达19种的有机磷农药均能较好的分离,峰面积与浓度之间呈现良好线性,相关系数r≥0.9994,定量检出限为2.5~16.9μg/kg。蔬菜加标回收率为62.4%~111.5%,相对标准偏差(RSD)为0.74%~5.26%。结论该法操作简便,灵敏,准确,重现性好,适用于蔬菜中多种常见有机磷农药残留的测定和分析。     

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.