二维液相色谱法测定保健食品中V_A、V_(D3)、V_E的含量

目的建立了二维液相色谱法测定保健食品中VA、VD3、VE含量的方法。方法采用甲醇与乙醇超声直接提取样品,以Eclipse Plus C18(2.1 mm×100 mm,1.8μm)为一维色谱柱,流速为0.5 ml/min;以poroshell 120(4.6 mm×100 mm,2.7μm)为二维色谱柱,流速为1.0 ml/min;采用波长切换方式检测(VA:325 nm;VD3:264 nm;VE:296 nm),以乙腈-甲醇-水为流动相,梯度洗脱,柱温为35℃。结果维生素A在0.21μg/ml~8.38μg/ml、维生素D3在0.04μg/ml~1.73μg/ml、维生素E在2.05μg/ml~81.84μg/ml线性关系良好,相关系数r均为1.000 0,平均回收率为95.6%~102.7%。结论本方法快速、准确、重现性好,适用于保健食品复合维生素片或软胶囊中VA、VD3、VE的测定。     

高效液相色谱法测定保健食品中松果菊苷

目的:建立高效液相色谱法测定保健食品中松果菊苷的方法。方法:样品经50%甲醇提取,以0.2%磷酸-乙腈为流动相,流速为1.0 ml/min,Intersil C18柱分离(柱温为35℃),在331 nm处检测。结果:被测组分在28μg/ml～280μg/ml范围内线性关系良好(r=0.9999);加标回收率为89.3%～101.2%,相对标准偏差(RSD)2.92%～3.50%(n=6)。方法检出限为0.84μg/ml,方法定量限为2.81μg/ml。结论:本方法快速、灵敏、重现性好,适用于保健食品中松果菊苷的测定。     

高效液相色谱法同时测定保健食品中水飞蓟宾和五味子醇甲

目的建立保健食品中水飞蓟宾和五味子醇甲的高效液相色谱测定方法。方法样品经甲醇超声提取,被测物采用Poroshell 120 EC-C18(4.6 mm×100 mm,2.7μm)分离柱;流动相为甲醇-水,梯度洗脱,流速为0.7 ml/min;水飞蓟宾和五味子醇甲的紫外检测波长分别为287 nm和250 nm。根据保留时间定性,外标峰面积法定量。结果水飞蓟宾在0μg/ml~243.9μg/ml线性相关系数为0.999 7,方法检出限为1.82μg/ml,相对标准偏差(RSD)为0.84%(n=6),样品的加标回收率为97.4%~102.1%;五味子醇甲在0μg/ml~43.3μg/ml线性相关系数为0.999 6,方法检出限为0.48μg/ml,相对标准偏差(RSD)为0.56%(n=6),样品的加标回收率为97.4%~102.5%。结论该方法简单、快速、灵敏和准确,可用于保健食品中水飞蓟宾和五味子醇甲的测定。     

高效液相色谱法法同时测定保健食品中丹参酮ⅡA和丹酚酸B的含量

目的建立高效液相色谱法同时测定保健食品中丹参酮ⅡA和丹酚酸B的含量。方法样品经75%甲醇-水(75∶25,V/V)超声提取,采用phenomenex Luna C_(18)色谱柱,以乙腈-0.1%(V/V)H_3PO_4溶液为流动相梯度洗脱,流速为1.0 ml/min,柱温为30℃,检测波长为286 nm、270 nm。结果丹参酮ⅡA和丹酚酸B分别在0.51μg/ml~25.4μg/ml、8.5μg/ml~318.8μg/ml时呈良好的线性关系(r=0.999 9、r=0.999 8)。低、中、高3种添加水平下加标回收率为94.2%~97.1%;相对标准偏差(RSD)为1.8%~2.6%。结论本方法简便、快捷、重复性好,可以用于保健食品中丹参酮ⅡA和丹酚酸B的含量测定。     

高效液相色谱法测定保健食品中的叶黄素

目的:建立测定保健食品中叶黄素含量的方法。方法:采用无水乙醇对试样进行提取,纯甲醇体系作为流动相,ODS C18柱,高效液相色谱(HPLC)进行分离检测。结果:方法的检出限为0.1μg/g,线性范围在0.3μg/ml～6.2μg/ml之间,RSD为5.9%,平均回收率为92%～105%。结论:该方法具有简便、快速、可靠、容易推广等优点,适用于液体、片剂、粉剂、胶囊、软胶囊样品的测定。     

固相萃取-超高效液相色谱法检测保健食品中维生素D_3

目的建立保健食品中维生素D3的固相萃取-超高效液相色谱方法。方法样品经皂化、萃取、定容后,利用硅胶柱固相萃取的净化技术,采用C18柱分离,甲醇水混合溶液作为流动相,PDA检测器检测,检测波长为264 nm。结果经硅胶固相萃取柱净化后,杂质能较好的去除,维生素D3的浓度为0.1μg/ml~5.0μg/ml时,其峰面积与质量浓度呈良好的线性关系回归方程为y=46 152x-1 735.1,相关系数(r)为0.999 6,回收率为87.8%~105.8%,相对标准偏差(RSD)为1.28%~3.58%(n=6),方法的检出限为1.0μg/100 g。结论利用本方法,可以测定保健食品中维生素D3含量,经净化后可消除杂峰的干扰且峰形较好,回收率高、快速简便,是测定保健食品中维生素D3含量的有效定量方法。     

HPLC法测定保健食品中姜黄素含量及稳定性研究

目的建立保健食品中姜黄素的液相色谱法,并用于保健食品中姜黄素的稳定性研究。方法样品中的姜黄素经甲醇回流提取后,经Ultimate XB-C18(100 mm×4.6 mm,3μm)分离,流动相为乙腈-4%冰乙酸(48∶52,V/V),流速:0.8 ml/min;紫外检测波长为430 nm,根据保留时间定性,外标峰面积法定量。结果姜黄素在4.953 5μg/ml~79.256 0μg/ml内线性关系良好(r=1),样品的加标回收率为98.0%~103.5%,平均回收率为100.8%,RSD为2.0%;检出限为0.027μg/ml;定量限为0.093μg/ml,样品经过3个月的加速破坏性试验,检测其中的姜黄素含量平均下降比率为1.6%。结论该方法具有操作简便快速、分离效果好、精密度和准确性高、重现性好的特点,可为姜黄素类保健食品的质量控制提供方法参考,同时样品中姜黄素的含量变化不大,具有良好的稳定性。     

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。     

高效液相色谱法测定添加维生素保健食品中叶酸

目的建立高效液相色谱法测定添加维生素保健食品中叶酸含量方法。方法采用C18色谱柱(250 mm×4.6mm,5μm)分离,甲醇:磷酸氢二钾(0.025mol/L,pH=6.0)20:80为流动相,流速0.8ml/min,二极管阵列检测器检测,检测波长为280nm,以保留时间定性,外标法定量。结果叶酸在0.1~0.8 mg/ml范围内有良好的线性关系,相关系数为0.999 92;检出限0.48mg/100g。样品测定的精密度相对标准偏差0.97%;加标回收率97.0%~99.5%,平均回收率98.5%。结论高效液相色谱法测定叶酸的方法具有良好的精密度和准确度,方法操作简单适用于多维钙中叶酸含量的测定。     

保健食品中总黄酮醇苷测定方法研究

目的建立保健食品中总黄酮醇苷的酸水解-高效液相色谱测定方法。方法采用甲醇回流提取总黄酮醇苷,酸水解法水解为槲皮素、山柰素和异鼠李素3种苷元,用高效液相色谱仪测定3种苷元含量,计算总黄酮醇苷含量。结果甲醇-25%盐酸(4∶1)在85℃水浴中回流提取0.5 h能使样品完全水解。最佳色谱条件:ODS C18色谱柱(150 mm×4.6 mm,5μm),流动相:甲醇-0.6%磷酸溶液(47∶53),柱温:35℃,检测波长:360 nm。槲皮素在4.766~95.52μg/m L、山柰素在5.052~101.0μg/m L、异鼠李素在2.027~48.66μg/m L的浓度范围内,线性关系良好(r=0.999 1、0.999 4、0.999 4);测定样品的相对标准偏差(RSD)为0.57%;平均加标回收率分别为98.25%、99.81%和101.8%,回收率试验的RSD分别为3.82%、3.31%和4.86%;槲皮素、山柰素检出限为0.50μg,异鼠李素为0.80μg,总黄酮醇苷为4.52μg。同一份样品采用本方法测定的总黄酮醇苷含量低于采用《保健食品检验与评价技术规范》(2003年版)中方法测定的总黄酮含量。结论本方法简便、结果稳定、重复性强,可应用于保健食品中总黄酮醇苷的含量测定。     

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.