固相萃取-高效液相色谱法测定水和土壤中二氯喹啉酸残留

目的 建立测定水和土壤中二氯喹啉酸残留量的高效液相色谱检测方法,为二氨喹啉酸残留研究提供重要技术支持.方法 水和土壤经不同溶剂提取浓缩后,经阴离子交换柱净化浓缩,用高效液相色谱-紫外检测器进行定量分析.结果 结果表明,二氯喹啉酸经过净化浓缩后,无明显杂质干扰测定,水和土壤的添加浓度在5.0～100 μg/kg时,回收率分别在91％～96％、89％～98％,变异系数均小于7％,方法最低检出浓度水中为0.6 μg/L、土壤中为1.0 μg/kg.结论 该方法对水和土壤中二氯喹啉酸残留的检测灵敏度高,重现性好,满足农药残留痕量检测需求.     

超高效液相色谱法快速测定罗汉果中乙螨唑的残留量

目的 建立超高效液相色谱法检测罗汉果中乙螨唑残留的分析方法。方法 样品经乙腈溶液提取,氯化钠盐析,加入无水硫酸镁脱水、并经过优化后的中性氧化铝和石墨化炭黑(GCB)填料组合进行净化,最后超高效液相色谱测定,基质标准溶液外标法定量。结果 乙螨唑在0.05 mg/L～5.0 mg/L浓度内具有良好的线性关系,相关系数>0.999,方法的检出限为0.01 mg/kg,在0.05 mg/kg、1.0 mg/kg和2.0 mg/kg 3个添加水平下,乙螨唑在罗汉果的平均回收率为95.6%～102.9%,精密度为1.90%～2.74%。结论 该方法样品前处理过程简单快速,分析时间短,符合农药残留试验的要求,适用于罗汉果中乙螨唑残留量的分析。     

气相色谱-串联质谱法测定水果中多种农药残留

目的:建立水果中38种农药残留的气相色谱-串联质谱分析方法。方法:样品用乙酸乙酯匀浆提取后,固相萃取法净化,采用气相色谱-串联质谱法-选择反应监测模式(SRM)测定,内标法定量。结果:在0.01 mg/L～10 mg/L范围内线性相关系数均大于0.99,分别在香蕉和番石榴中添加三个浓度水平(0.01 mg/kg,0.02 mg/kg,0.1 mg/kg)的混标,平均回收率为68%～120%,方法的相对标准偏差为0.41%～6.38%(n=6)。所有农药的方法定量限均小于10μg/kg。结论:该方法简单、灵敏、准确,具有良好的回收率和稳定性,较好的解决了样品本底的基质干扰,适用于水果中多种农药残留的测定。     

改进的QuEChERS-凝胶渗透色谱-气相色谱/质谱法[JP]测定保健食品中53种农药残留

目的 建立保健食品中53种农药残留的QuEChERS-凝胶渗透色谱-气相色谱/质谱检测方法。方法 样品经QuEChERS提取、凝胶渗透色谱柱净化后,DB-5MS (25m×0.25mm,0.25μm）色谱柱分离,质谱检测器检测,外标法定量。结果 在0.02mg/kg添加水平样品的平均回收率除甲胺磷等8种农药在55.7%～77.2%范围内,其余为78.0%～115.2%;相对标准偏差除氧化乐果和甲基毒死蜱大于10%外,其余均小于10 %;在0.05mg/kg添加水平样品的平均回收率除甲胺磷等6种农药在57.7%～77.3%范围内,其余均在78.4%～113.5%范围内;相对标准偏差除氧化乐果外,其余农药均小于10%。速灭威等6种农药的检出限为0.0240～0.0901mg/kg,其余为0.0012～0.0200mg/kg。结论 该方法消耗试剂少,分析成本低,操作简便快速,适合保健食品中53种农药残留的检测。     

气相色谱法在测定小麦中烯唑醇的应用

目的建立气相色谱ECD检测器测定粮食中烯唑醇农药残留的方法。方法样品中烯唑醇经乙腈提取浓缩后,石墨化碳固相萃取柱净化,DB-1701毛细管柱分离,气相色谱-电子捕获检测器(ECD)检测,外标法定量。结果烯唑醇在浓度0.05～1.00μg/mL范围内线性关系良好,相关系数r=0.9997,最低检出限0.02mg/kg。添加浓度为0.05mg/kg、0.10 mg/kg、0.20mg/kg、0.50mg/kg、1.00mg/kg时,回收率为76.0%～105.0%,相对标准偏差6.0%～10.0%。结论该方法准确灵敏,具有实际应用价值。     

土壤中6种白蚁防治药物的超高效液相色谱检测方法研究

目的建立超高效液相色谱法(UPLC)测定土壤中6种白蚁防治药物——吡虫啉、氟虫腈、虫螨腈、毒死蜱、氰戊菊酯、联苯菊酯残留量的分析方法。方法样品用乙腈匀浆提取,经离心、NH2固相萃取小柱净化、浓缩、定容后,采用超高效液相色谱法进行测定,外标法定量。结果所有农药在0.01~5.00 mg/L范围内线性关系均良好,相关系数r20.99;所有农药的方法检出限均低于10μg/kg;在0.050 0、0.167和0.500 mg/kg添加水平下,样品平均回收率为83.0%~117.0%,相对标准偏差RSD为2.0%~4.4%。结论本方法简便,重现性良好,可用于土壤中吡虫啉、氟虫腈、虫螨腈、毒死蜱、氰戊菊酯、联苯菊酯6种药剂残留的检测。     

固相萃取-气相色谱/质谱法测定茶叶中的农药残留

目的:应用气相色谱--质谱联用技术,建立同时测定茶叶中有机磷、有机氯、氨基甲酸酯、拟除虫菊酯等四类41种农药残留的方法。方法:茶叶样品经乙腈提取、固相萃取净化、浓缩,经过HP-5色谱柱程序升温分离,选择离子模式测定。结果:该方法检出限为(0.002～0.1)mg/kg,最低定量限(0.007～0.4)mg/kg。添加水平为(0.125～10.0)mg/kg时,测定41种农药加标回收率为59.2%～123.8%。相对标准偏差4.8%～23.1%。结论:该方法灵敏度高,回收率好,能够快速、准确地检测茶叶中41种农药残留。     

固相萃取结合气相色谱-质谱法测定水果中的溴螨酯残留

目的建立测定橙子、苹果和葡萄中溴螨酯残留量的气相色谱-质谱方法。方法样品经均质提取、串联固相萃取柱净化后,经气相色谱-质谱仪检测,外标法定量。结果方法检出限为5μg/kg。橙子中的溴螨酯添加水平为10、50、2000μg/kg时,回收率为80.1%～103.6%,相对标准偏差为7.8%～10.6%;苹果中的溴螨酯添加水平为10、50、2000μg/kg时,回收率为73.5%～104.7%,相对标准偏差为7.4%～11.4%;葡萄中的溴螨酯添加水平为10、50、2000μg/kg时,回收率为72.0%～104.8%,相对标准偏差为6.7%～11.7%。结论该方法适用于水果中溴螨酯残留的测定,具有快速、定量准确、检测灵敏等优点。     

茶叶中34种有机磷和氨基甲酸酯农药多残留的测定

目的 建立一种快速测定茶叶中有机磷和氨基甲酸酯农药多残留的气相色谱法.方法 样本中农药残留在超声波振荡条件下用乙腈提取,其提取液经氮气流浓缩和凝胶渗透色谱净化,用气相色谱一氮磷检测器测定,色谱柱为HP-5,30 m×0.32 mm×0.25 mm.分析茶叶中26种有机磷类、8种氨基甲酸酯类农药的残留量.结果 农药的添加水平在0.208～0.792 mg/kg范围时,在绿茶中的平均添加回收率为81.2%～114.0%,RSD 为3.45%～13.50%;在花茶中的平均添加回收率为81.3%～110.0%,RSD为3.68%～14.50%;检测限范围为0.02～0.08 mg/kg.结论 本方法的优点是快速、灵敏、准确、成本低,能满足农药多残留快速扫描的分析要求.     

茶叶中溴虫腈及联苯菊酯农药残留的固相萃取-气相色谱串联质谱仪测定法

目的建立固相萃取-气相色谱串联质谱仪法(GC-MS/MS)测定茶叶中溴虫腈、联苯菊酯农药残留方法。方法茶叶样品经乙腈提取,佛罗里硅土固相萃取(SPE)小柱净化后,气相色谱串联质谱仪测定进行多反应监测(MRM)分析,内标法定量。结果溴虫腈、联苯菊酯在相对浓度0.1～5.0范围内线性关系良好(r≥0.999),定量检出线分别为0.011和0.002 mg/kg,在加标浓度0.15～1.50 mg/kg范围内,溴虫腈、联苯菊酯平均加标回收率为74.4%～97.6%,相对标准偏差(RSD)分别为6.3%～9.2%(n=6)。结论 SPE-GC-MS/MS检测灵敏、定性准确、定量精确,适合茶叶中溴虫腈和联苯菊酯农药残留的测定。     

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.