高效液相色谱法测定肉中激素残留量

目的 :建立 HPL C法测定肉与肉制品中己烯雌酚、雌二醇、沙丁胺醇、戊酸雌二醇、苯甲酸雌二醇残留量的方法。方法 :样品经甲醇超声萃取、离心 ,提取液浓缩后经 0 .4 5μm FH滤膜过滤 ,进高效液相色谱分析。结果 :五种激素浓度与峰面积成正比的工作曲线 ,相关系数 r>0 .9999;其变异系数 CV≤ 0 .6 (n=6 ) ,检出限≤ 3.5 ng,回收率范围为 95 .4～ 10 2 .5 %。结论 :该法具有灵敏、准确、精密、样品处理简单 ,杂质干扰少等优点     

深圳市市售肥牛、羊肉中雌激素残留状况分析

[目的]了解深圳特区市售肥牛、羊肉中雌二醇、戊酸雌二醇、炔雌醚、苯甲酸雌二醇4种激素残留状况.[方法]样品经超声萃取、离心、反革、净化、衍生,然后用GC-MS法进行分析. [结果]80份样品中(肥牛肉40份,羊肉40份),雌二醇含量在3～12 ng/g之间,其余3种雌激素均未检出. [结论]深圳超市销售的肥牛、羊肉除含有天然浓度的雌二醇外,没有戊酸雌二醇、炔雌醚、苯甲酸雌二醇3种人工合成雌激素残留.     

HPLC法同时测定肉与肉制品中沙丁胺醇和8种雌激素残留量

目的：建立HPLC法测定肉与肉制品中沙丁胺醇、β－雌已醇、炔雌醇、已烯雌酚、双烯雌酚、已雌酚、戊酸雌二醇、苯甲酸雌二醇、炔雌醚残留量的方法。方法：样品经甲醇超声萃取、离心，提取液浓缩后经0．45μmFH滤膜过滤，进高效液相色谱分析。结果：9种组分得到很好分离，并得到浓度与峰面积成正比的工作曲线，相关系数γ＞0．999；其变异系数CV≤1.1％（n=6），检出限≤6ng，回收率范围为84．5％－101％。结论：该法具有灵敏、准确、精密、样品处理简单、无杂质干扰等优点。     

羊肉中环境雌激素的气相色谱-质谱测定法

目的 建立羊肉中环境雌激素(4-壬基酚、双酚A、己烯雌酚、17α-乙炔基雌二醇、17α-雌二醇、17β-雌二醇、雌三醇、雌酮)的气相色谱-质谱(GC-MS)测定法.方法 肉样经乙腈-乙酸乙酯(体积比为3:2)混合溶液提取后用同相萃取柱净化.被测组分经五氟丙酸酐(PFPA)衍生后用GC-MS进行检测.结果 8种环境雌激素在0.2～5.0μg/kg内呈良好的线性关系,相关系数为0.997 4～0.999 7,该法测定的峰面积的日内相对标准偏差为1.25%～5.85%,检出限为0.024～1.40μg/kg.回收率除17α-乙炔基雌二醇较低(55.4%)外,其他为71.5%～111.0%.结论 该方法 准确、灵敏,精密度好,适于羊肉中环境雌激素的测定.     

气相色谱-质谱法测定奶粉中的环境雌激素

[目的]建立奶粉中的环境雌激素(4-壬基酚、双酚A、已烯雌酚、17α-乙炔基雌二醇)和内源性雌激素(17α-雌二醇、17β-雌二醇、雌三醇、雌酮)的气相色谱-质谱(GC-MS)测定方法。[方法]样品经乙腈沉淀蛋白质后取上清液氮气流浓缩至干,经五氟丙酸酐(PFPA)衍生化后用GC-MS进行检测。[结果]该法测定的峰面积的日内相对标准偏差为1.25%～5.85%,检出限为0.024～1.40μg/kg。回收率为72.2%～102.5%。[结论]该方法准确、灵敏,精密度好,适于奶粉中环境雌激素的测定。     

同位素稀释的气相色谱-质谱法测定食品模拟物中邻苯二甲酸酯类增塑剂

目的建立同位素稀释法测定4种食品模拟物中18种邻苯二甲酸酯(PAEs)类增塑剂的方法。方法水模拟物、3%(W/V)乙酸模拟物和20%乙醇模拟物中的18种增塑剂用正己烷萃取,95%乙醇模拟物加水稀释至20%乙醇后,再用正己烷萃取,采用GC-MS进行分析,同位素稀释法定性定量。结果 18种PAEs经内标校正后的线性R2≥0.9991;线性范围DINP和DIDP为0.2~5.0 mg/L,DMEP、DEEP和DBEP为0.02~2.0 mg/L,其他13种化合物的线性范围为0.005~2.0 mg/L;18种PAEs的内标相对回收率85.3%~115.0%,DIDP和DINP的定量限为200.0μg/L,其余16种PAEs的定量限为0.1~6.7μg/L,RSD≤10%。结论与以往的国标方法相比,该方法扩大了邻苯二甲酸酯类的检测范围,解决了高醇模拟物的检测结果不稳定的问题,采用同位素稀释法定性定量,结果更准确,方法更简单、可靠。     

中空纤维液相微萃取-高效液相色谱联用分析牛奶中痕量雌二醇

目的:建立了中空纤维液相微萃取-高效液相色谱联用(HP-LPME-HPLC)的方法,用于分析检测牛奶中痕量的雌二醇的含量。方法:采用自制的中空纤维萃取装置,考察并优化了影响HP-LPME的因素,仅用100μl正辛醇作为萃取溶剂,在600 rpm搅拌速度下萃取1 h,雌二醇的富集倍数可达200倍。结果:雌二醇在1.00 ng.m l-1~125 ng.m l-1范围内线性关系良好(R=0.9985),最低检出限0.571 ng.m l-1,平均回收率分别为96.4%、98.7%、98.1%。结论:该方法样品前处理简单、成本低,且灵敏度高、环境友好,适用于痕量雌二醇的分析检测。     

HPLC法测定肉与肉制品中雌激素、沙丁胺醇残留量

[目的]建立Hplc法测定肉与肉制品中雌二醇、已烯雌酚、沙丁胺醇残留量的方法.[方法]样品经甲醇提取,提取液浓缩后经0.45μmFH滤膜过滤,进高效液相色谱分析.[结果]得到雌二醇、已烯雌酚、沙丁胺醇浓度与峰面积成正比的工作曲线,相关系数r＞0.999;其相对标准差RSD≤0.6%(n=6),检出限≤2ng,回收率范围为95.8～102.5%.[结论]该法具有灵敏、准确、精密、样品处理简单、杂质干扰少等优点.     

气相色谱-质谱测定黄酒中的敌敌畏

目的建立气相色谱-质谱(GC-MS)测定黄酒中敌敌畏的检测方法。方法同时优化了液液萃取和固相萃取2种前处理方法,液液萃取法称取40 g样品加4 ml甲苯萃取,振摇后加5 g NaCl,5 000 r/min离心5 min,有机相进GC-MS选择离子模式检测分析。固相萃取选用C_(18)柱,经5 ml甲醇、5 ml水活化,称取10 g黄酒上样,过柱后用5 ml水淋洗,2 ml乙酸乙酯洗脱,45℃氮气吹至近干,用乙酸乙酯定容至1 ml进GC-MS分析。结果敌敌畏在0.05 mg/L～10.0 mg/L内线性良好,r值0.999 8。液液萃取法平均回收率为89.4%～94.5%,固相萃取法平均回收率为102%～114%,2种前处理方法最低检出限(LOD)接近,分别是0.125μg/kg～0.155μg/kg、0.150μg/kg～0.204μg/kg。固相萃取法与液液萃取法相比操作简单、回收率高、敌敌畏富集效率高,所用试剂更加环保安全。结论固相萃取与GC-MS联用适用于黄酒中敌敌畏的检测分析。     

气相色谱-质谱法测定水产品中的有机锡

目的：建立水产品中三丙基锡、三丁基锡和三苯基锡的气相色谱-质谱（GC-MS）分析方法。方法：水产品经冷冻干燥、有机溶剂萃取、凝胶色谱净化,再用四乙基硼化钠衍生化生成乙基化的有机锡,经硅胶柱净化浓缩后,以气相色谱-质谱法测定。结果：方法线性范围0.5-200 ng/g,相关系数r2≥0.993,加标平均回收率76%-113%,相对标准偏差RSD〈10%,方法的检出限在0.33-0.97 ng/g之间。结论：该方法操作相对简便快速,能很好地应用于水产品中有机锡的测定。     

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.