固相萃取-高效液相色谱法检测水中多种拟除虫菊酯类农药

[目的]研究同时测定水中甲氰菊酯、氯氟氰菊酯、溴氰菊酯、氰戊菊酯、氯菊酯5种拟除虫菊酯类农药污染物的固相萃取-高效液相色谱方法. [方法]水样经C18小柱富集,以异丙醇洗脱,采用光电二极管阵列检测器检测,利用C18色谱柱分离,以乙腈溶液和纯水为流动相等梯度洗脱,流速1.0 mL/min,在波长205 nm进行测定,外标法定量. [结果]5种拟除虫菊酯类农药在0.0～5.0 mg/L浓度范围内具有良好的线性关系,方法最低检测质量浓度为0.025～0.050 μg/L,回收率范围为88.0％～102.2％,相对标准偏差为1.0％～3.8％. [结论]该固相萃取-高效液相色谱法灵敏、准确,适用于水源水及生活饮用水中痕量拟除虫菊酯类农药残留的检测.     

固相萃取-气质联用法测定水中三氯杀螨醇及百菌清

目的:建立了水中多种拟除虫菊酯类农药残留的固相萃取-气相色谱-质谱(GC/MS)联用检测方法。方法:采用C18固相萃取碟富集吸附水样中目标组分,以二氯甲烷洗脱浓缩; DB-5MS毛细管柱分离,采用选择离子监测SIM的质谱扫描模式进行定性定量分析。结果:在50~400μg/L浓度范围内线性关系良好,相关系数均>0 .995,三氯杀螨醇、百菌清加标平均回收率为90 .0% ~101 .1%,方法的相对标准偏差为4. 2% ~8. 3%,水样浓缩2 .500倍的最低检测限分别为0 .0012、0. 0024μg/L。结论:本法具有非常高的选择性、灵敏度和准确度,完全能满足水中痕量三氯杀螨醇及百菌清的分析。     

气相色谱法同时测定食用菌中20种有机氯和拟除虫菊酯类农药残留

目的建立同时测定食用菌中20种有机氯和拟除虫菊酯类农药残留的方法。方法食用菌样品中残留的农药经溶剂提取后,采用全自动固相萃取净化,经氮吹浓缩,用气相色谱-微电子捕获检测器测定,外标法定量。结果食用菌中20种有机氯和拟除虫菊酯类农药组分的分离效果好,在各自的浓度范围内呈良好的线性关系,相关系数皆〉0.999,样品加标回收率为79.3%～102.4%,RSD为2.0%～6.7%。结论该方法快速、简便、灵敏、准确,适合于食用菌中多种有机氯和拟除虫菊酯类农药残留的测定。     

气相色谱法同时测定食用菌中20种有机氯和拟除虫菊酯类农药残留

目的 建立同时测定食用菌中20种有机氯和拟除虫菊酯类农药残留的方法.方法 食用菌样品中残留的农药经溶剂提取后,采用全自动固相萃取净化,经氮吹浓缩,用气相色谱-微电子捕获检测器测定,外标法定量.结果 食用菌中20种有机氯和拟除虫菊酯类农药组分的分离效果好,在各自的浓度范围内呈良好的线性关系,相关系数皆>0.999,样品加...     

气相色谱法测定中药材中菊酯类农药残留的研究

目的为了更加有效测定中药材中拟除虫菊酯类农药的残留量,采用气相色谱法检测,固相萃取净化的分析方法,提高药材的用药安全性。方法在临海市各个药材公司购置主要为药厂提供的中药材品种,每个品种选择3~5个批号,共计150个样品,经提取净化后采用气相色谱法(GC-ECD)测定,可同时测定6种拟除虫菊酯类农药残留量。结果 6种拟除虫菊酯类成分均有检出,检出率为34. 51%,农药的残留含量主要在0. 01~0. 05mg/kg之间,合格率为85. 23%;中药材中6种拟除虫菊酯类农药的平均回收率在83. 14%~103. 81%之间,相对标准偏差(RSD)为4. 0%~6. 4%,6种拟除虫菊酯类农药的线性范围在0. 02~0. 84mg/L之间;最低检测限范围为15. 8~26. 3ng/kg,定量限范围为52. 8~88. 4ng/kg。结论气相色谱法用于拟除虫菊酯类农药残留的检测,对于成分的分离效果好,灵敏度高,指标满足农药残留分析检测的要求,可以为中药材中拟除虫菊酯类农药残留的限量制定提供有效的数据参考。     

茶叶中8种拟除虫菊酯类农药残留QuEChERS-气相色谱检测法

目的建立QuEChERS-气相色谱电子捕获检测器分析茶叶中8种拟除虫菊酯类农药残留量的方法。方法茶叶中残留的拟除虫菊酯类农药用0.1%乙酸乙腈提取,选取适量的(N-丙基乙二胺填料)PSA粉、ODSC18和石墨化炭黑粉进行分散固相萃取,净化液上GC-ECD分析。结果 8种拟除虫菊酯类农药的加标回收率为78.2%～109.0%,相对标准偏差为1.5%～7.9%,最低检出浓度为0.006～0.03 mg/kg。结论 QuEChERS-GC-ECD同时检测茶叶中8种拟除虫菊酯类农药残留,方法简单、快速、方便,结果满意。     

气相色谱测定蔬菜中农药残留量的方法探讨

目的建立气相色谱法测定蔬菜中杀菌剂和拟除虫菊酯类农药的分析方法。方法蔬菜经粉碎，加入乙腈匀质提取，盐析，40℃氮吹，正已烷溶解，过弗罗里矽柱，滤液在40℃再次氮吹近干，正已烷定容，采用DB—17毛细管柱分离，ECD检测器测定，一次进行2种杀菌剂和4种拟除虫菊酯类农药的检测。结果样品加标回收率在89.3％～109．6％之间，相对标准偏差在1．1％-8．3％之间，检出限在0．0018～0．037mg／Kg之间。结论实验结果表明，该方法简便、快速、灵敏、准确，各项技术指标满足蔬菜中杀菌剂和拟除虫菊酯类农药检测需要。     

毛细管气相色谱法测定韭菜中拟除虫菊酯类农药多残留

目的：测定韭菜中5种拟除虫菊酯类农药残留。方法：应用柱层析净化技术和毛细管气相色谱法,并采取程序升温模式和不分流进样方式在μ-ECD检测器上同时测定韭菜样品中5种拟除虫菊酯类农药多残留组分。结果：5种拟除虫菊酯类农药分离效果较好,其线性范围较宽,并在此浓度范围内与峰面积呈良好的线性关系;同时方法的最小检测限低于1.00μg/L（0.214-0.904μg/L）,相对标准偏差均小于10%（2.48%-8.05%）,其加标回收率在86.26%-102.64%之间。结论：本研究建立的方法简便、快速、经济,具有良好的灵敏度、精密度和准确度,可以满足韭菜样品中拟除虫菊酯类农药多残留检测要求,同时对其他蔬菜中拟除虫菊酯类农药多残留分析具有一定的参考价值。     

自动固相萃取-气相色谱串联质谱法测定果蔬中的多组分农药残留

目的建立一种同时测定果蔬中有机磷、氨基甲酸酯类及拟除虫菊酯类等多组分农药残留的分析方法。方法果蔬样品经乙腈提取,无水硫酸钠脱水,固相萃取小柱净化,再经旋转蒸发及氮吹浓缩后,用GC-MS/MS进行测定,外标法定量。结果有机磷、氨基甲酸酯类及拟除虫菊酯类等多组分农药经过36 min后完全分离,在0.01~10.0μg/ml的线性范围内相关系数r均0.9956,平均加标回收率在72.1%~109.3%之间,相对标准偏差在4.0%~11.3%之间。结论该方法不仅前处理简便易操作,而且具有较高的灵敏度、准确度和精密度,适合于大批量样品的日常检测。     

GC法测定8种拟除虫菊酯类农药残留的含量

目的:建立气相色谱法测定蔬菜、水果中拟除虫菊酯类农药残留含量的方法。方法:采用气相色谱-电子捕获检测器对8种拟除虫菊酯类农药残留量进行检测。结果:各组分在HP-5毛细管色谱柱(30 m×320μm×0.25μm)分离良好;在0.04μg/ml～8.0μg/ml范围内具有良好的线性关系;其回收率在67%～126%。结论:该方法准确可靠,可用于蔬菜水果中拟除虫菊酯农药残留的检测。     

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.     

The human drama of genetics: 'hard' and 'soft' media representations of inherited breast cancer

This paper examines media coverage of 'breast cancer genetics', and explores its implications for public understanding. We present a content analysis of coverage in British newspapers and look at a variety of popular forms, including women's magazines, television soap opera and radio drama. Genetic/inherited risk receives a great deal of coverage across a wide range of media formats and outlets. Much of this attention has focused on individuals from 'high risk families' and dilemmas around prophylactic mastectomies. Through examining media coverage, combined with interviews with media personnel and their sources, we show why this story proved so attractive to the media and highlight the different production values which influence coverage. Finally, we introduce preliminary findings from focus group discussions to demonstrate how such 'human interest' framing has engaged audience attention and influenced public understandings. The paper concludes by highlighting the implications for analysing, predicting, and engaging with, media representations of science.     

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.     

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.     

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.     

The risk of heat exhaustion at a deep underground metalliferous mine in relation to surface temperatures

The risk of heat exhaustion at a deep underground metalliferous mine was assessed in relation to thermal conditions prevailing on the surface. For each day of a 1-year prospective case series of heat exhaustion, surface 24-h mean wet and dry bulb temperatures were recorded. From this data, 24-h mean wet bulb globe temperatures were derived using certain assumptions. The three surface temperature variables were significantly higher on those days on which heat exhaustion occurred, compared to those days on which it did not occur (P < 0.001). The relative risk of heat exhaustion on days when the 24-h mean wet bulb globe temperature was in the range 26.0-28.0 degrees C was 4.82 (95% confidence interval 2.12-10.96). Surface temperature data could be used at this mine to warn miners about the risk of heat exhaustion.