高效液相色谱法快速检测水中5种拟除虫菊酯残留量

目的建立反相高效液相色谱法测定水中5种拟除虫菊酯残留量的方法。方法样品经过滤后进行反相高效液相色谱测定,色谱柱Waters Symmetry C185μm,4.6mm×250mm,流动相为乙腈∶水=78∶22（V/V）,流速1.0mL/min,二极管阵列检测器,检测波长205nm。结果 5种拟除虫菊酯类农药分离良好,在0.050~5.0mg/L范围内有良好线性关系,检出限分别为：甲氰菊酯2.5μg/L、氯氟氰菊酯3.0μg/L、溴氰菊酯3.0μg/L、氰戊菊酯3.0μg/L、氯菊酯5.0μg/L;回收率在95.2%~98.4%。结论该法操作简便快捷、方法稳定性好,适用于水中拟除虫菊酯农药残留的快速检测。     

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。     

反相高效液相色谱法测定血清中维生素E的含量

目的:建立反相高效液相色谱(RP HPLA)测定人血清中维生素E(VE)浓度的方法。方法:移取血清,加入乙腈乙醇混合溶液及正己烷,旋涡混合、离心,分离正己烷层,氮气吹干,残渣用流动相溶解后进样。采用XTerraTMRP18色谱柱(5μm,3.9×150 mm),流动相为甲醇∶水(92∶8,v/v);流速1 m l/m in;柱温30℃;检测波长292 nm。结果:VE的保留时间为7.61 m in,浓度在2~16μg/m l范围内线性关系良好(r2=0.9999,n=5),平均回收率为95.6%,RSD<6%,最低检测量2 ng(S/N>3)。40例健康成人血清VE平均值为10.20±2.51μg/m l。结论:反相高效液相色谱检测血清VE浓度的方法灵敏度高,回收率和重现性良好,操作快速、简便,这对测定血清中其它维生素含量具有指导意义。     

HPLC法同时测定保健品中腺苷和虫草素含量的研究

目的:建立保健品中腺苷和虫草素含量的测定方法。方法:样品用水超声提取,反相高效液相法同时测定腺苷和虫草素两种成分。色谱条件为:Diamonsil C18色谱柱(150 mm×4.6 mm,5μm),乙腈-水为流动相(6:94,V/V),检测波长为260 nm。结果:腺苷和虫草素在1.0～100.0μg/m l范围内线性良好,回收率为95.2%～99.1%,相对标准偏差为1.10%～3.05%,检测限均为0.1μg/ml。结论:本法简便、准确,可同时测定保健品中的腺苷和虫草素。     

超高效液相色谱法同时测定饮用水中4种挥发酚

目的建立同时测定饮用水中苯酚、间甲酚、3,4-二甲酚、2,5-二甲酚的超高效液相色谱方法。方法样品直接过滤测定。采用Acquity UPLC BEH C_(18)(2.1 mm×100 mm,1.7μm)色谱柱分离,荧光检测器检测。甲醇-水(50∶50,V/V)为流动相,流速为0.20 ml/min,荧光检测器激发波长为268 nm,发射波长为310 nm。外标法定量。结果水中4种挥发酚在6 mim内完成检测,在1.0μg/L~20.0μg/L内线性关系良好(r≥0.999 7),方法的检出限为0.04μg/L~0.29μg/L,回收率为86.0%~102.6%,相对标准偏差(RSD)为0.86%~5.88%。结论该方法操作简单、快速、灵敏,可用于饮用水中挥发酚的检测。     

水果中甲霜灵和氯噻啉的固相萃取-反相高效液相色谱测定法

目的建立水果中甲霜灵和氯噻啉的固相萃取-反相高效液相色谱测定法。方法以乙酸乙酯-环己烷(V∶V=1∶1)为提取溶剂,以超声波法提取水果中的甲霜灵和氯噻啉,经固相萃取净化,采用液相色谱法测定。液相色谱检测波长为230 nm,流动相为乙腈-水(体积比为60∶40),流量0.8 ml/min,进样量20μl。结果甲霜灵和氯噻啉线性范围分别为1.0×10-6～1.0×10-2g/m(l r=0.999 0)和1.0×10-6～1.0×10-4g/m(l r=0.999 8),平均回收率分别为97.94%～99.95%和97.98%～100.43%,检出限分别为2.56×10-5和3.43×10-4μg/g,RSD分别为2.07%和2.87%。结论该方法操作简便快速,可作为水果中甲霜灵和氯噻啉含量的检测。     

红曲类保健食品中洛伐他汀检测的方法研究

目的:为准确测定红曲类保健食品中洛伐他汀的含量,对高效液相色谱法测定洛伐他汀进行了优化。方法:采用Agilent EclipseXDB-C18(5μm,4.6*250 mm)色谱柱分离;流动相为甲醇∶水∶磷酸=385∶115∶0.14(V∶V∶V);流速1.0 ml/min;检测波长238 nm测定。结果:洛伐他汀在8μg/ml～400μg/ml范围内呈现良好的线性(r=0.9999),检出限为4μg/ml,加标回收率为88.6%～93.7%,方法精密度RSD为1.68%。结论:该方法简便、快速、准确,适用于保健食品中洛伐他汀含量的测定。     

固相萃取高效液相色谱法检测水中二苯胺残留量

目的:建立固相萃取高效液相色谱法测定水中二苯胺残留量的方法。方法:样品经固相萃取后进行高效液相色谱测定。色谱柱为SUPELCO Discovery C185μm 250×4.6 mm,流动相为:甲醇:0.02 mol/L NH4AC(pH=4.2)=70:30(V/V),流速为0.8 ml/min,二极管阵列检测器,检测波长为280 nm。结果:该方法的线性范围为:0.050～10.0μg/ml;标准曲线线性良好,其回归方程及相关系数r为Y=348.4X-3.5,r=0.99999。检出限为:0.60μg/L;回收率在99%～103%之间,相对标准偏差小于2.0%。结论:该方法操作简便、快捷,是水中二苯胺残留量的快速而准确的检测方法。     

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。     

TSK凝胶色谱系统测定头孢妥仑匹酯中高分子聚合物

目的采用TSK凝胶色谱柱对头孢妥仑匹酯中的高分子聚合物进行测定。方法高效液相色谱法,以TSK-gel G2000 SW_(XL)(7.8 mm×300 mm)为色谱柱,流动相为水-甲醇(5∶95,V/V),流速为0.7 ml/min,检测波长为230 nm,进样体积为20μl。结果高分子聚合物峰与主成分头孢妥仑匹酯峰能够有效分离,头孢妥仑匹酯主成分的线性范围为5.35μg/ml~1 694.00μg/ml(r=0.998 5),在该范围内,供试品溶液浓度与聚合物峰面积呈良好线性关系(r=0.999 6);定量限为0.54μg/ml,检测限为0.16μg/ml;方法的精密度良好(RSD=0.21%);样品测定的重复性较好(RSD=0.62%)。结论该方法简便,快速,灵敏度高,重复性好,可用于头孢妥仑匹酯及其他脂溶性抗生素中高分子聚合物的检测。     

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 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.