气相色谱-质谱法测定咖啡类饮品中3种糠醛类物质

目的 建立咖啡类饮品中糠醛、5-甲基糠醛、5-羟甲基糠醛的气相色谱-质谱测定方法。方法 样品加入5 ml 50%乙醇溶液、5 ml 10%碳酸钠溶液超声提取10 min, QuEChERS净化管净化,以HP-INNOWAX毛细管柱(30 m×0.25 mm, 0.25μm)分离,质谱检测器检测,内标标准曲线法定量。结果 本法在0.05μg/ml～10.0μg/ml浓度内呈良好的线性关系,r>0.999,检出限为0.2 mg/kg,平均回收率为94.9%～102.6%,相对标准偏差<10%。结论 该方法适合咖啡中3种糠醛类物质的检测。     

气相色谱-氮磷检测器测定牛奶及奶粉中三聚氰胺

目的:建立应用气相色谱-氮磷检测器测定牛奶及奶粉中三聚氰胺含量的方法。方法:样品用三氯乙酸提取,MCX阳离子固相萃取柱净化后,采用DB-1701毛细管柱和氮磷检测器进行检测。结果:方法线性范围在0.05μg/ml～5μg/ml,定量限为0.1 mg/kg(牛奶)和0.25 mg/kg(奶粉),相对标准偏差为2.1%～7.9%,回收率为86.4%～108%。结论:本方法不经衍生化处理直接测定三聚氰胺,简便、快速,灵敏度较高。     

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。     

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。     

简易串联柱-气相色谱法测定溶剂型油墨中苯的含量

目的 基于串联柱-气相色谱技术,建立一种用于测定溶剂型油墨中苯含量的检测方法。方法 油墨样品通过二硫化碳溶解,用甲醇净化后,由氢火焰离子化检测器-气相色谱完成检测,样品组分的色谱分离在一根自制的简易串联毛细管色谱柱上展开,该柱由一根6 m的HP-INNOWa X毛细管色谱柱(0.25 mm×0.25μm)和一根30 m的HP-VOC毛细管色谱柱(0.20 mm×1.12μm)串联组成。结果 在该串联色谱柱上,油墨中常见的干扰物质,如1,2-二氯乙烷、四氯化碳等化合物得到了较好的分离。本方法的线性范围为5μg/ml～500μg/ml,线性良好,方法的检出限为2 mg/kg,样品添加浓度50 mg/kg～400 mg/kg的平均回收率为95%～106%,相对标准偏差为3.9%～6.3%。结论 本方法预处理简便,净化效果佳,可用于溶剂型油墨中苯残留的检测。     

凝胶渗透色谱净化-气相色谱法测定酱腌菜中山梨酸和苯甲酸

目的:建立凝胶渗透色谱净化-气相色谱法测定酱腌菜中山梨酸和苯甲酸的方法。方法:样品中山梨酸和苯甲酸经过乙醚提取,凝胶渗透色谱净化,毛细管柱(FFAP,30 m×0.32 mm×0.25μm)分离后,FID检测器检测。结果:山梨酸和苯甲酸在50μg/ml～800μg/ml时与峰面积有良好的线性关系(r0.999),检出限(3S/N)分别为0.55 mg/kg和0.84 mg/kg,加标回收率为82.2%～91.7%,相对标准偏差(n=3)为0.5%～5.5%。结论:该方法能满足酱腌菜中山梨酸、苯甲酸的测定要求。     

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。     

QuEChERS-超高效液相色谱串联质谱法测定蜂蜜中11种喹诺酮类药物残留

目的 优化改进QuEChERS-超高效液相色谱串联质谱(UPLC-MS/MS)测定蜂蜜中11种喹诺酮类药物残留的方法。方法 样品经均质后,对比不同的提取体系和净化条件,以及基质效应的变化,优化色谱质谱条件。结果 优化改进QuEChERS-超高效液相色谱串联质谱(UPLC-MS/MS)方法,选择冰乙酸-乙腈-水体系(1∶84∶15)溶液为提取试剂,采用C18+PSA(300 mg+125 mg)混合吸附剂净化,流动相为40%甲醇-乙腈和0.1%甲酸水溶液,同时优化色谱条件,结果各目标化合物在1.0～100.0μg/L质量浓度范围内线性关系良好,相关系数r均>0.995;回收率为72.4%～107.5%,相对标准偏差(RSD)为1.9%～8.1%,11种喹诺酮类药物检出限在0.4～1.0μg/kg,定量限在1.3～3.0μg/kg。结论 该方法快速经济,准确可靠,适合大批量蜂蜜样品中喹诺酮类药物残留的快速测定。     

茶叶中13种农药的气相色谱-三重四极杆质谱测定法

目的建立茶叶中虫螨腈、啶虫脒、茚虫威、硫丹、三氯杀螨醇、毒死蜱和拟除虫菊酯等13种农药残留的气相色谱-三重四极杆质谱检测方法。方法样品经乙腈提取,SPE净化,气相色谱-三重四级杆质谱-多反应监测模式(MRM)分离检测。结果本法虫螨腈、联苯菊酯和甲氰菊酯在0. 08μg/ml～3. 0μg/ml浓度内呈良好的线性,其余10种农药在0. 08μg/ml～5. 0μg/ml浓度内呈良好的线性关系,线性相关系数在0. 996～0. 999 6;检出限为0. 03μg/kg～1. 0μg/kg,加标回收率为77. 4%～109. 4%,RSD为5. 9%～18. 6%。结论该方法简便、快速、灵敏、抗干扰能力强,重现性好,能满足茶叶中13种农药定性和定量检测的要求。     

QuEChERS-气相色谱-质谱联用法测定温棚蔬菜中7种氨基甲酸酯及5种拟除虫菊酯农药残留

目的建立温棚蔬菜中5种拟除虫菊酯及7种氨基甲酸酯的Qu ECh ERS-气相色谱-质谱联用测定法。方法蔬菜样品经乙腈提取,利用Qu ECh ERS法净化,GC-MS分离检测蔬菜中的农药残留。结果氨基甲酸酯在0.07~5.00μg/ml浓度范围内,拟除虫菊酯在0.05~5.00μg/ml浓度范围内,相关系数均大于0.9949%;氨基甲酸酯的检出限为0.18~0.37μg/kg,平均回收率为72.50%~98.75%,相对标准偏差在1.62%~4.13%之间;拟除虫菊酯的检出限为0.27~0.86μg/kg,平均回收率为75.00~103.6%,相对标准偏差在1.37%~5.92%之间。结论该方法简便、灵敏、准确,适用于蔬菜中氨基甲酸酯和拟菊酯类农药残留检测。     

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 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.