高效液相色谱-二极管阵列检测法测定保健食品中枸橼酸西地那非的研究

目的:以紫外检测器检测、根据色谱峰的绝对保留时间定性,对可疑阳性样品用二极管阵列检测器再定性,用外标法峰面积定量,建立保健食品中违禁成分—枸橼酸西地那非的测定方法。方法:采用反相高效液相色谱法,D iscoveryC184.6×150 mm色谱柱,柱温30℃,流动相为40 mmol/L磷酸三乙胺(pH=3.2)∶甲醇∶乙腈=48∶30∶22(v∶v∶v),流速为0.80 m l/m in,检测波长为291.0 nm。结果:其工作曲线的线性范围:20.0~320μg/m l,相关系数:r=0.9998,回收率:96.3%~98.0%,精密度(n=6):1.55%~1.75%。结论:方法准确、可靠,可用于保健品中枸橼酸西地那非的检测。     

反相高效液相色谱法同时测定儿童血清中维生素A和E

目的 :建立反相高效液相色谱法同时测定儿童血清中维生素 A和维生素 E的方法 ,以了解深圳市儿童营养状况 ,并为制订饮食建议提供参考。方法 :取血清 2 0 0 μl,加入脱醛无水乙醇 2 0 0 μl,振荡 ,加入正己烷萃取 ,将正己烷吹干后用流动相溶解 ,进样。色谱条件为 :色谱柱 Suplco C 18柱 (15 cm× 4 .6 m m,5μm) ,流动相为甲醇 :水 (93 7) ,检测波长 30 0 nm。结果 :维生素 A在 6 .5 4～ 6 5 .4 0 μg/ L 浓度范围内呈线性 ,r=0 .99995 ,维生素 E在 0 .10～ 5 .0 5 mg/ L 浓度范围内呈线性关系 ,r=0 .9999;维生素 A和维生素 E的平均回收率分别为 98.2 4 % (α=2 .92 % )和 95 .73% (α=3.80 % )。结论 :本法检测儿童血清中维生素 A及 E的浓度 ,方法快速、灵敏、准确 ,样品处理简便易行     

二极管阵列反相高效液相色谱法测定人血清中维生素E含量

目的:建立二极管阵列反相高效液相色谱法(PDA-HPLC)测定人血清中维生素E(α)含量的方法。方法:吸取血清,加入甲醇乙腈混合溶液及正己烷,旋涡混合、离心,分离正己烷层,氮气吹干,残渣用甲醇溶解后进样。采用XDB-C8色谱柱(5μm,4.6×150 mm),流动相为甲醇,流速1.0 ml/min,二极管阵列检测器检测。结果:α-VE浓度在2.1~21.0μg/ml范围内线性关系良好(r=0.9999,n=5),样品加标平均回收率为98.3%,相对标准偏差(RSD)<5%,最低检测量5 ng。结论:二极管阵列反相高效液相色谱法(PDA-HPLC)测定人血清中维生素E(α)含量的方法,定性准确,灵敏度高,回收率和重现性良好,操作快速、简便,结果准确可靠。     

反相高效液相色谱法检测水中五种拟除虫菊酯农药残留量

目的:建立反相高效液相色谱法测定水中五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。色谱柱为W elch M aterials AQ-C185μm 250×4.6 mm,流动相为∶乙腈∶水=78∶22(V/V),流速为1.0 m l/m in,二极管阵列检测器,检测波长为205 nm。结果:各组分分离良好,在0.050μg/m l~5.0μg/m l范围内具有良好的线性关系,其回收率在98%~102%之间。结论:该方法操作简便、快捷、可靠,可用于水中拟除虫菊酯农药残留量的检测。     

高效液相色谱内标法测定血清中维生素A

目的:研究以维生素A乙酸酯为内标测定血清中维生素A的高效液相色谱方法。方法:血清样品及内标维生素A乙酸酯经正己烷萃取,正己烷层挥干后无水乙醇定容,以甲醇-水(98∶2)为流动相,反相C18柱分离,二级管阵列检测器检测。结果:维生素A浓度在0.11μg/ml～1.65μg/ml范围内,峰面积比例与浓度呈良好线性关系,维生素A的最低检测限为0.020μg/ml,相对标准偏差为3.1%～6.6%,回收率为90.0%～107.2%。240例样品血清维生素A含量为0.191μg/ml～1.298μg/ml,平均值为0.559μg/ml。结论:该方法灵敏、准确、操作简便、快速、重复性好,可用于人血清中维生素A的测定含量。     

HPLC法测定血清肉碱的研究

目的:建立高效液相色谱(HPLC)测定血清中肉碱浓度的方法。方法:血清样品用乙腈、甲醇沉淀蛋白,加入肉碱衍生剂,60℃恒温水浴2h后进样10μl。色谱柱为AtlantisC18柱(4.6mm×150mm,5μm),流动相为甲醇∶异丙醇∶乙腈(35∶45∶20,v/v),流速1.0ml/min,紫外检测波长260nm。结果:在上述色谱条件下,血清肉碱分离良好,回归方程为Y=8490X-48200,r=0.9999,线性范围为12.5~400μmol/L。最低检测浓度为12.5μmol/L。日内精密度1.6%~13.2%,日间精密度(%)1.8%~12.1%,回收率98.5%。结论:通过加入肉碱衍生剂,建立了HPLC法测定血清中肉碱浓度的方法。此法操作简单,耗时少,有良好的准确度,适用于临床检测。     

高效液相色谱法测定奶粉中磷脂酰胆碱含量研究

目的:建立应用高效液相色谱-紫外检测器测定奶粉中磷脂酰胆碱(PC)含量的方法。方法:奶粉中PC经乙醚萃取后,采用XDB C18(150 mm×4.6 mm×5μm)色谱柱,以乙腈∶甲醇∶异丙醇=10∶80∶10(v/v/v)为流动相,流速为1.0 m l/m in,柱温为35℃,UV 208 nm检测。结果:奶粉中PC的平均回收率为86.4%,RSD为3.21%(n=6),线性范围为0.050~0.40 mg/m l(r=0.9990)。结论:建立的方法用于奶粉中PC含量的测定,操作简便、快速。     

HPLC-DAD同时测定食品中维生素A、D、E研究

目的:建立反相高效液相色谱-二极管阵列检测法(HPLC-DAD)同时测定食品中维生素A、维生素D和维生素E(α-生育酚)的含量。方法:取一定量食品样品加入乙醇、氢氧化钾及焦性没食子酸,80℃水浴皂化30 m in,石油醚提取后,氮气吹扫浓缩致干后用流动相溶解,进样10μl分析;色谱条件为:色谱柱Supelco C18柱(15 cm×4.6 mm,5μm),流动相甲醇∶水(93∶7),柱温40℃,DAD扫描波长范围190~370 nm,检测波长325 nm(V itam in A)、265 nm(V ita-m in D)、294 nm(V itam in E)。结果:维生素A在1.0~100.0μg/L浓度范围内线性良好,相关系数r=0.9999;维生素D2在1.0~100.0μg/L浓度范围内相关系数r=0.9997;维生素D3在1.0~100.0μg/L浓度范围内相关系数r=0.9998;维生素E在0.50~50.0 mg/L浓度范围内相关系数r=0.9999。维生素A、维生素D和维生素E的平均回收率基本在95%以上,用本法调查了119种食品中维生素A、维生素D和维生素E的含量。结论:方法快速、灵敏、准确,样品处理简便易行,可用于食品中脂溶性维生素A、D、E的同时测定。     

HPLC法快速测定保健食品中维生素D3的含量

目的:检测保健食品营养补充剂中的维生素D3的含量。方法:选用正己烷+无水乙醇+水为溶剂系统提取样品中的维生素D3,采用正相高效液相色谱,μBondpak氨基色谱柱(美国W aters公司,3.9×300 mm),以正己烷+异丙醇=99+1为流动相,265 nm为检测波长,外标法定量的方法。结果:线性范围为0.50~5.0μg/m l,相关系数为0.9994,最低检测限为0.002μg,低浓度平均回收率(n=5)为85.2%,中浓度平均回收率(n=5)为108.0%。RSD(n=5)为8.12%。结论:该方法操作简便,分离效果好,尤其适用于测定保健食品营养补充剂中维生素D3的含量。     

高效液相色谱法同时测定血清中几种脂溶性维生素

目的:采用高效液相色谱(HPLC)技术同时测定维生素A(VA)、维生素E(VE)、β-胡萝卜素(β-C)和番茄红素(Ly)。方法:HPLC柱:AlltechODS5μm(250mm×4.6mmi.d.);流动相:甲醇∶乙酸乙酯∶正己烷=7∶2∶2(v∶v∶v);检测波长:VA,VE,β-C和Ly的检测波长分别为325nm、292nm、450nm和472nm(波长编程,自动转换)。灵敏度:0.002AUFS;流速:1.0ml/min。结果:VA,VE,Ly和β-C的保留时间分别是4.5,6.5,9.4和13.4min,4种成分峰独立完整,无干扰峰,峰形和分离效果良好,并在15min之内可完成分析测定。结论:本研究首次建立了一次同时测定VA、VE、β-C和Ly的方法,既节省时间和试剂,又快速、准确。     

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.