凝胶渗透色谱和固相萃取净化气相色谱-质谱法检测动物性食品中26种有机氯农药残留

目的:建立一种测定动物性食品中有机氯类多种农药残留的气相色谱质谱分析方法。方法:采用丙酮和正己烷提取肉中多种有机氯类农药,以凝胶渗透色谱(GPC)和固相萃取(SPE)净化、浓缩后,用气相色谱—质谱选择离子监测方式分析检测26种有机氯农药残留。结果:所有26种农药均在20 min内流出,分离良好,农药标准的线性范围在0.01 mg/L～0.5 mg/L相关系数r均在0.99以上,低、高两种浓度加标回收率均在61%～95%之间,相对标准偏差均小于13%,方法最低检出限在0.002 mg/kg～0.005 mg/kg。结论:本方法适合动物性食品中有机氯类农药残留的测定。     

气相色谱法同时检测茶叶中12种农药残留

目的:建立同时检测茶叶中12种有机磷和有机氯农药残留的气相色谱法。方法:用丙酮和石油醚混合溶剂浸提,石墨化碳柱固相萃取。采用电子捕获检测器、程序升温、OV-1701(30 m×0.25 mm×0.25μm)毛细管柱气相色谱法检测。结果:12种农药的回收率为79.0%～102.1%,相对标准偏差RSD为1.87%～3.34%;检出限为0.008 mg/kg～0.051 mg/kg;12种农药线性范围为0.1 mg/L～15.0 mg/L,相关系数r≥0.9923。结论:该方法简便、灵敏、准确,适用于分析茶叶中的12种有机磷和有机氯农药残留含量。     

气相色谱法测定植物纤维食品包装材料中邻苯二甲酸酯类增塑剂

目的:建立气相色谱法测定植物纤维食品包装中邻苯二甲酸酯类增塑剂的方法。方法:样品中的增塑剂采用正己烷溶剂经超声提取,提取液以硅胶固相萃取柱净化,HP-5毛细管柱分离,FID检测器检测5种邻苯二甲酸酯类增塑剂,外标法定量,质谱法确证。结果:各增塑剂的最低检出限范围为0.05 mg/kg～1.50 mg/kg,回收率范围为82.1%～104.8%,相对标准偏差为1.14%～3.07%(n=10)。结论:该方法操作简便、快速、灵敏,测定结果良好,可以作为植物纤维食品包装中邻苯二甲酸酯类增塑剂的检验方法。     

固相萃取-毛细管柱测定大米、茶叶中的有机氯农药残留

目的:建立了同相萃取-毛细管柱测定大米、茶叶中的有机氯农药残留方法.方法:采用石油醚:丙酮(5:1,v/v)超声波提取样品,Florisil固相萃取柱净化,用OV-1701弹性石英毛细管程序升温气相色谱法测定.结果:本优化方法应用于测定茶叶和大米8种有机氯农药残留量均有较宽的线性范围(0.001～0.1μg/ml)和较好的线性相关(r=0.9938-0.9992),重现性较好(RSD=1.5%～5.2%),检出限为5.7 × 10-4～5.8×10-3μg/ml.结论:该方法准确、快速、灵敏度高.     

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。     

气相色谱法测定土壤中14种有机氯农药

目的:采用气相色谱法建立土壤样品中有机氯农药的检测方法。方法:土壤样品干燥过筛后,对比了旋涡振荡、超声、匀浆三种样品提取方式,采用固相萃取小柱净化,经气相色谱(ECD)检测。结果:超声提取效果优于其他两种提取方式,14种有机氯农药在0.005μg/ml～1.0μg/ml的浓度范围内线性良好(R>0.99);添加浓度在5.0μg/kg、50μg/kg水平下,14种OCPs的平均回收率范围分别为80.2%～112%、80.6%～110%,相对标准偏差范围分别为4.77%～11.3%、1.41%～8.12%,方法检出限为0.80μg/kg～1.51μg/kg。结论:该方法操作简便,灵敏度高,能够满足土壤中有机氯农药残留的检测。     

固相萃取-气相色谱法测定蔬菜中7种有机氯和拟除虫菊酯农药残留

目的:建立蔬菜中7种有机氯和拟除虫菊酯农药残留的毛细管气相色谱测定方法。方法:样品被乙腈经匀浆、超声、震荡提取后,无水硫酸钠脱水,旋转蒸干后经Carb/NH2柱和硅镁柱净化,氮气吹干,以正己烷定容,再通过DB-1701毛细管柱和ECD检测器进行定性定量测定。结果:7中有机氯和拟除虫菊酯农药的分离效果好,定量分析呈良好的线性关系,相关系数均大于0.998,检出限在0.00020 mg/kg～0.0044 mg/kg范围,平均回收率在60%～120%范围,RSD在2%～6%范围。结论:该方法具有快速、简便,准确度和精密度好的优点,适合蔬菜中多种有机氯和拟除虫菊酯农药残留的检测,用于实际样品的检测取得了较好的效果。     

检测螃蟹中有机氯类农药残留的全自动GPC-SPE联合净化气相色谱法

目的建立气相色谱定量测定螃蟹中19种有机氯(OCPs)类混合农药残留的方法。方法样品用乙腈提取,环己烷-乙酸乙酯(1∶1,V/V)定容,凝胶渗透色谱(GPC)和氨基固相萃取柱(Carb/NH2)联合净化,经气相色谱(GC)检测分析。结果 19种化合物在0.02~2 mg/L内线性关系良好(r0.993),各有机氯的检出限为0.04~0.31μg/kg(S/N=3)。在加标水平为20、40、80μg/kg时,方法的回收率为81.3%~116.2%,相对标准偏差为0.6%~7.5%。结论该方法选择性好、灵敏度高,样品净化效果好,适用于螃蟹中有机氯类农药的多残留痕迹测定。     

哈尔滨市售蔬菜中有机磷和拟除虫菊酯农药的残留量

目的了解哈尔滨市蔬菜中有机磷农药、拟除虫菊酯类农药的残留情况,为政府相关部门制订政策提供依据。方法于2007年5—10月,从哈尔滨市10个主要农贸市场和5个超市采集大辣椒、小辣椒、黄瓜、西红柿、豆角、菠菜、油菜、大头菜、花菜和白菜菜样各15件,采用气相色谱法检测其农药的残留情况。结果共检测出4种有机磷农药(甲胺磷:0.003 1～0.048 8mg/kg;敌敌畏:0.001 5～0.052 7mg/kg;氧化乐果:0.003 9～0.3449mg/kg;水胺硫磷:0.0026～0.0869mg/kg)和3种拟除虫菊酯类农药(氯氰菊酯:0.018 1～0.324 5 m/kg;氰戊菊酯:0.024 7～0.024 8 mg/kg;溴氰菊酯:0.039 4～0.044 1 mg/kg)残留,甲拌磷、乐果、甲基对硫磷均未检出残留。农药残留超标率由高至低依次为氧化乐果(24.00%)>甲胺磷(20.67%)>水胺硫磷(4.67%)。氧化乐果在10种蔬菜中均有检出,氯氰菊酯在9种蔬菜中检出,敌敌畏和甲胺磷分别在7种蔬菜中检出。结论本次调查的蔬菜中普遍存在有机磷、拟除虫菊酯类农药的残留。     

蔬菜中有机磷及有机氯农药的大口径毛细管气相色谱测定法

目的 建立蔬菜中残留有机氯及有机磷农药的大口径毛细管气相色谱测定法.方法 采用大口径毛细管气相色谱分析技术代替传统的填充柱气相色谱技术,采用程序升温分离蔬菜中残留的多种有机氯及有机磷农药.结果 本实验中敌百虫、敌敌畏、甲拌磷、乐果、甲基对硫磷、杀螟硫磷、马拉硫磷、倍硫磷、乙基1605最低检出浓度为0.004～0.008mg/kg,线性范围为0.5～5.0μg/ml,相关系数为0.996 5～0.999 0,平均回收率范围为88.47%～96.51%,RSD为2.98%～5.16%.α-666、β-666、γ-666、δ-666、P,P'DDE、o,p'-DDT、P,P'DDD、P,P'-DDT的线性范围为0.002～0.2 μg/ml,相关系数为0.999 4～0.9997,最低检出浓度为0.0007～0.001 mg/kg,平均回收率范围86.51%～98.45%,RSD为2.47%～5.32%.结论 该法可以很好地分离蔬菜中残留的多种有机氯和有机磷农药,灵敏度高,结果准确可靠.     

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.