ASPE/GC-MS法测定蔬果中25种有机磷农药残留

目的:建立蔬果中25种有机磷农药残留全自动固相萃取/气相色谱质谱分析方法。方法:采乙腈均浆提取样品中的有机磷类农药,通过全自动固相萃取仪提取净化,用气质联用进行分析。结果:25种有机磷农药在0.05 mg/kg～5.0 mg/kg范围内均有较好的线性,相关系数均在0.99以上,最低检出限为0.004 mg/kg,25种有机磷农药回收率加标0.5 mg/kg时,为80.2%～98.7%之间,加标1.0 mg/kg时,为74.2%～99.8%之间,变异系数RSD,加标0.5 mg/kg时,为1.1%～4.8%之间,加标1.0 mg/kg时,为1.5%～6.8%之间。结论:此法简便,快速,净化效果好,回收率高,可同时测定水果、蔬菜中的多种有机磷农药残留。     

全自动固相萃取/气相色谱质谱法快速测定蔬果中农药残留

目的:建立蔬果中11种有机磷农药残留全自动固相萃取/气相色谱质谱分析方法。方法:用乙腈匀浆提取样品中的有机磷类农药,通过全自动固相萃取仪提取净化,用气质联用仪进行分析。结果:11种有机磷农药在0.1 mg/kg~2.0 mg/kg范围内线性相关系数均在0.99以上,最低检出限为0.005 mg/kg,11种有机磷农药加标0.1 mg/kg时,回收率为78.5%~102.5%,加标0.5 mg/kg时,为76.8%~99.6%;相对标准偏差分别为1.4%~5.5%和1.8%~6.2%。结论:此法简便,快速,净化效果好,回收率高,可同时测定水果、蔬菜中的多种有机磷农药残留。     

固相萃取-双柱双检测器-气相色谱法测定蔬菜中55种有机磷农药残留

目的:建立了固相萃取-双柱双检测器-气相色谱法测定蔬菜中多种有机磷农药残留的方法。方法:样品中的有机磷农药经乙腈-丙酮混合溶剂匀浆提取,Carb-NH2固相萃取柱净化,DB-1701柱分离后进入FPD检测器进行定性定量、HP-5分离后进入NPD检测器进行验证。结果:在0.5μg/ml～10.0μg/ml范围内质量浓度与峰面积有良好的线性关系,加标回收率在70%～124%之间,相对标准偏差(RSD)在2.31%～10.4%,方法检测限在0.005 mg/kg～0.030 mg/kg。结论:该方法充分利用双柱定性的优势,检测结果准确、可靠,达到农残检测的要求,适用蔬菜中多种有机磷的同时测定。     

固相萃取-气相色谱法检测蔬菜中17种残留的有机磷农药

目的：建立固相萃取-气相色谱法测定蔬菜水果中17种有机磷农药残留量的分析方法。方法：蔬菜水果捣碎经乙腈提取,盐析,浓缩,CARB/NH2柱净化,丙酮溶解定容,用AT-1701中性毛细管柱和FPD检测器测定。结果：相关系数为0.9965-0.9993,17种有机磷农药回收率加标1.0 mg/kg时,为80.5%～98.2%之间,加标10.0 mg/kg时,为90.1%～99.7%之间,变异系数RSD,加标1.0 mg/kg时,为1.75%～6.12%之间,加标10.0 mg/kg时,为2.19%～5.82%之间。结论：实验结果表明,在选定的色谱条件下,采用固相萃取-气相色谱法对蔬菜中17种有机磷农药残留量进行测定。本法线性范围宽,线性良好,重现性强,回收率很高,能满足有机磷农药残留量测定,完全能够达到国家标准方法的要求。     

蔬菜中8种有机磷农药残留监测方法研究

目的:建立同时测定8种有机磷农药残留的方法。方法:采用乙腈提取,经蒸发浓缩,使用双柱(DB-17/HP-1)进行定性定量分析,使用GC-MS法进行确证。结果:8种有机磷在DB-17、DB-1色谱柱上可完全得到分离;工作曲线在0.5 mg/ml～2.0 mg/ml范围,相关系数为0.9970～0.9999;检出限0.007 mg/kg～0.126 mg/kg;加标回收实验显示,添加水平为0.05 mg/kg时,平均回收率81.1%～113.7%,RSD2.4%～14.1%;添加水平为0.50 mg/kg时,平均回收率86.8%～116.0%,RSD4.5%～11.7%。结论:本方法灵敏度符合GB 2763的评价需要,准确度和精密度与国标方法相当。     

混合固相萃取柱净化-气相色谱质谱联用法快速测定果蔬中10种农药残留的研究

目的:建立果蔬中10种除草剂、杀菌剂、杀虫剂农残的混合固相萃取柱-气相色谱质谱联用分析方法。方法:样品经乙腈提取,盐析,活性炭-氨基混合柱净化,采用气相色谱-质谱测定,基质匹配外标法定量。结果:在0.05μg/ml～2.00μg/ml范围内,相关系数r>0.992,样品在0.05 mg/kg～0.50 mg/kg范围内加标,平均回收率在79.77%～118.33%之间,相对标准偏差(RSD)为3.17%～11.35%,检测限(LOD)在0.001 mg/kg～0.006 mg/kg之间。结论:该方法快速、可操作性强、净化效果较好,可同时满足蔬菜水果中多种农药残留的检测需要。     

固相萃取-气相色谱法测定杨梅中的有机磷

目的:建立了固相萃取气相色谱法测定杨梅中22种有机磷农药残留的方法.方法:用乙腈-丙酮混合溶刺匀浆提取样品中的有机磷农药,固相萃取柱净化,用FPD检测器对其进行测定.结果:对40种宁波地产杨梅进行了检测,加标回收率在70%～95%之间,方法检测限在0.005～0.015 μg/kg,在0.2～20.0μg/ml范围内有良好的线性关系.结论:该方法简单、准确、可靠,分析结果达到农残检测的要求,适用大批量样品的同时检测.     

车载式气相(色谱仪)现场快速检测9种农药残留的方法研究

目的：建立用车载式气相（色谱仪）现场快速检测9种有机磷农药残留的分析方法。方法：采用改进的QuECh-ERS前处理方法、SRI 8610C车载式气相色谱仪（选用DB-1701毛细管柱、FPD检测器）对9种农药残留进行检测。结果：浓度在0.1～2.0μg/ml范围的标准曲线,其线性相关系数在0.9959～0.9991之间,样品加标回收率为80.0%～108.0%,RSD为2.35%～11.78%,最低检出限为0.052～0.114 mg/kg。结论：本方法简便、快速、安全,可用于果蔬样品农药残留的现场检测。     

固相萃取-气相色谱-质谱仪联用同时测定蔬菜中多种有机磷和硫丹类农药残留

目的建立快速测定蔬菜中有机磷和硫丹类农药残留的固相萃取-气相色谱-质谱仪联用检测方法。方法采用乙腈提取,Carb/NH2固相萃取柱净化,DB-17MS石英毛细管色谱柱,以GC-MS选择离子监测模式检测蔬菜中12种有机磷和3种硫丹类。结果 15种农药组分线性范围在0.2~1.0μg/ml之间,标准曲线线性系数r0.99,检出限在0.01~0.08 mg/kg,定量下限0.05~0.26 mg/kg之间,样品高、低两个浓度加标回收率在76%~117%之间,相对标准偏差(RSD)在1.27%~6.53%之间。结论方法准确度高、灵敏度好、重现性好、快速,适用于蔬菜中有机磷和硫丹类农药残留测定。     

凝胶渗透色谱净化-气相色谱法测定果蔬中36种有机磷农药残留

目的:建立凝胶渗透色谱净化-气相色谱法测定果蔬中多种有机磷农药残留的方法。方法:采用乙腈高速匀浆提取,PSA和石墨化碳黑分散性固相萃取净化,结合GPC去除色素及在线浓缩的前处理技术,用气相色谱-脉冲火焰光度检测器(GC-PFPD)测定。结果:果蔬中36种有机磷农药取得较好分离效果,在10.0μg/L～500μg/L范围内质量浓度与峰面积有良好的线性关系,标准曲线的相关系数均大于0.993,平均加标回收率为70.2%～117.4%,相对标准偏差(RSD)为1.35%～12.4%,方法最低检测限为0.003 mg/kg～0.009 mg/kg。结论:该方法操作简便快捷、经济、灵敏度高,适用于一般实验室开展日常监测和检测。     

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.     

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.     

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.     

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.