同时测定大豆中二苯醚类除草剂的多残留

[目的]建立同时测定大豆中苯达松、三氟羧草醚、氟磺胺草醚、苯草醚、甲羧除草醚、精恶唑禾草灵、除草醚、乙羧氟草醚、乙氧氟草醚9种二苯醚类除草剂多残留量的高效液相色谱分析方法。[方法]将样品中的二苯醚类除草剂用乙腈提取、凝胶色谱和Florisil固相萃取小柱净化后,经C8色谱柱分离,采用二极管阵列检测器检测。[结果]对样品的提取、净化及液相色谱的分离条件进行了优化。待测9种二苯醚类除草剂在0.10～10.0mg/L质量浓度范围内呈良好的线性关系,相关系数r=0.9971～0.9998,方法的精密度RSD为1.49%～4.65%,在0.05～0.5mg/kg的添加水平范围内,加标回收率为75.4%～101.9%,方法的检出限(S/N=3)为6.9～36μg/kg。同时对待测除草剂的液相色谱-质谱确证实验进行了研究。[结论]所建立的方法简便、快速,适用于大豆中9种二苯醚类除草剂残留量的同时测定。     

固相萃取-高效液相色谱法测定果蔬汁中6种酯类防腐剂

[目的]建立同时检测果蔬汁中对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯、对羟基苯甲酸异丙酯、对羟基苯甲酸异丁酯6种酯类防腐剂的固相萃取-高效液相色谱分析方法.[方法]果蔬汁用PEP-SAX-PSA小柱固相萃取,采用Waters XBridge C18色谱柱分离,以0.025mol/L磷酸二氢钠和甲醇为作流动相,梯度洗脱,紫外检测器定.[结果]对样品前处理和色谱分离条件进行了优化.在优化的条件下,6种防腐剂在1.00～50.0 μg/ml范围内的线性良好(相关系数≥0.999 1).对于10 g样品本方法的检出限可达0.025g/kg,相对标准偏差为1.2%～3.1%,加标回收率为80.5%～95.1%.[结论]所采用的固相萃取样品前处理方法简便、准确、有机试剂用量少且提取效率高,方法适用范围广,可用于多种食品中酯类防腐剂含量的测定.     

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-HPLC荧光法测定蜂蜜中磺胺类药物残留

目的:建立采用固相萃取-高效液相色谱荧光法同时测定蜂蜜中5种磺胺类药物残留的方法。方法:蜂蜜样品经醋酸-醋酸钠缓冲溶液溶解后,用C18固相萃取小柱富集、净化,用乙腈洗脱,5种磺胺类药物经荧光胺衍生后,以2%醋酸(v/v)溶液-乙腈(50/50,v/v)为流动相,在C18色谱柱上(250 mm×4.6 mm,5μm)分离,荧光法在λEx=405 nm,λEm=495 nm处测定。结果:5种磺胺类药物在0.01~0.20 mg/L具有良好的线性,其相关系数均大于0.9995,加标回收率在82.0%~102.5%,RSD均小于5.3%,定量检出限为0.004 mg/kg。结论:该方法具有快速、灵敏、简便、准确等优点,能满足实际工作的需要。     

固相膜萃取-高效液相色谱法测定饮用水中12种氨基甲酸酯类农药残留

目的:建立固相膜萃取-高效液相色谱法测定饮用水中灭多威、涕灭威、速灭威、残灭威、呋喃丹、甲萘威、抗杀虫威、异丙威、硫双威、仲丁威、猛杀威、杀虫威等12种氨基甲酸酯类农药残留量的方法。方法:水样经C18固相萃取膜真空抽滤,滤膜用乙酸乙酯洗脱,洗脱液经氮吹、甲醇溶解,高效液相色谱法测定。结果:12种氨基甲酸酯类农药的线性范围为0.05 mg/L～25.0 mg/L,线性相关系数大于0.999,检出限为0.31 mg/L～1.25 mg/L,水样中氨基甲酸酯类农残最低检测浓度范围为0.005 mg/L～0.019 mg/L,加标回收率为59.3%～97.3%,RSD<7.5%。结论:本方法样品前处理方便、快捷,有机试剂用量少。     

全自动固相膜萃取-高效液相色谱法测定水源水中的16种多环芳烃

目的 建立全自动固相膜萃取结合高效液相色谱法测定水源水中的16种多环芳烃。方法 水样加入10%甲醇后上样,上样流速为100 ml/min,待测物经固相膜萃取后,采用二氯甲烷进行洗脱,浓缩后上机,梯度洗脱,C18色谱柱分离,DAD检测器检测,根据保留时间和峰面积进行定性定量分析。从色谱条件、溶剂置换条件和萃取液浓缩方式等对水中16种PAHs的全自动固相膜萃取-液相色谱方法进行了优化研究。结果 在0.05 μg/ml～5.0 μg/L范围内,相关系数r>0.999;16种多环芳烃的仪器检出限为0.28 ng/L～1.04 ng/L;对水源水样品进行3个浓度水平0.05 μg/L、0.5 μg/L和5.0 μg/L,平均回收率在29.4%～100.3%之间;相对标准偏差(RSD)为2.3%～9.2%。结论 本法自动化程度高,快速、灵敏、简单,适用于快速分析环境水样中的痕量多环芳烃。     

全自动固相萃取-气相色谱串联质谱法测定生活饮用水中9种除草剂残留

目的 建立生活饮用水中9种除草剂残留的固相萃取-气相色谱-串联质谱(GC-MS/MS)检测方法。方法 将水样pH调至1.0~2.0,经C18固相萃取柱萃取后,用乙酸乙酯-二氯甲烷(1〖DK〗∶1,v/v)洗脱,洗脱液经氮吹浓缩至近干,并用乙酸乙酯定容后测定。采用DB-35MS 毛细柱分离,选择离子扫描( SIM)模式检测,外标法定量。结果 9种除草剂在0.05~1.0 μg/ml范围内,线性关系良好,方法检出限为0.0001~0.0005 μg /L;平均回收率为72.30 %~105.34 %,相对标准偏差为2.16 %~6.39 %( n =6)。结论 本法操作简便、灵敏、准确,可用于饮用水中多种除草剂残留的同时检测。     

液相色谱/质谱联用法同时测定饮用水中6种二氯酚异构体研究

目的:建立一种新型、灵敏、准确的同时测定饮用水中2,6-二氯酚、2,3-二氯酚、2,4-二氯酚、2,5-二氯酚、3,4-二氯酚和3,5-二氯酚的液相色谱/质谱联用检测方法。方法:水样经Oasis HLB固相萃取小柱富集、净化后,在C8反相色谱柱(250 mm×4.0 mmi.d.,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,v/v/v)为流动相,采用大气压化学电离(APCI)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:161[M-H]-。结果:6种二氯酚异构体的日内与日间精密度分别小于11.7%和12.9%,它们在0.02-5.00μg/L范围均具有良好的线性,水样中各氯酚异构体的检出限在0.007-0.02μg/L。结论:本方法可用于饮用水中痕量二氯酚异构体残留的测定。     

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。     

固相萃取高效液相色谱法测定血浆中亚甲蓝含量

目的:建立血浆中亚甲蓝检测的高效液相色谱方法.方法:采用Waters OASIS HLB固相萃取小柱对血浆样品中残留的亚甲蓝进行萃取富集,采用高效液相色谱法SUNFIRE C18柱(5 μm 4.6×250 mm);流动相:水/乙腈/乙酸钠/乙酸/EDTA:750 ml/250 ml/6.5 g/8 ml/54 mg;流速:1.0 ml/min;柱温:25℃;二极管阵列检测器:293 nm进行分离测定,外标法定量.结果:在0.05～1.5 μmol/L浓度范围,其线性关系良好,Y=342950X 4298,相关系数(r)≥0.999.RSD为2.1%～3.8%,回收率可达到95%～99%.最低检测浓度为0.04 μmol/L.结论:该方法具有准确、灵敏、快速、简便等特点,能够用于经亚甲蓝处理的血浆样品的检测.     

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.     

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.