非抑制电导阳离子色谱法测定空气中的乙醇胺和三甲胺

目的:建立了空气中乙醇胺、三甲胺的离子色谱测定方法。方法:以20 mmol/L硫酸水溶液作为吸收液,以1.0 L/min流量采样20 min;采样后的溶液以甲基磺酸(MSA)和乙腈混合淋洗,Dionex IonPac SCS1柱分离,非抑制型电导检测。结果:乙醇胺和三甲胺在0μg/ml～200μg/ml范围相关系数均大于0.999,检出限分别为1.9μg/L和2.4μg/L,回收率分别为101.6%和99.0%,RSD均小于5.0%。结论:将该方法应用于实际空气样品的检测,结果满意。     

离子色谱法测定饮料中的几种甜味剂

目的建立离子交换-电导检测离子色谱法,同时测定饮料中的甜蜜素、安赛蜜和糖精钠的含量。方法选用Ion PacAS19 4 mm×250 mm为分析柱,Ion PacAS19 4 mm×50 mm为保护柱,18 mmol/L氢氧化钾作为淋洗液,流速为1.0 ml/min,样品经适当稀释滤膜过滤后进行色谱分析。结果方法的线性范围广、相关性好(r20.999),甜蜜素、安赛蜜和糖精钠测定的相对标准偏差(RSD)分别为0.29%~2.96%、0.61%~2.09%、0.47%~2.78%,加标回收率分别为97.2%~101.7%、97.3%~100.1%、98.1%~102.0%,方法检出限分别为0.40μg/ml、0.10μg/ml、2.0μg/ml。结论该方法简单、快速、准确,且灵敏度高。     

高效液相色谱法测定消毒液中的苯扎氯铵和苯扎溴铵

目的建立一种测定消毒液中苯扎氯铵和苯扎溴铵的反相离子对高效液相色谱法。方法将苯扎氯铵和苯扎溴铵消毒液过0.45μm微孔滤膜,采用高效液相色谱-二极管阵列检测器测定。色谱柱为C18柱,流动相为乙腈-0.02 mol/L己烷磺酸钠溶液(含0.1%三乙胺,V/V,用磷酸调节p H值至3.5±0.1,体积比为70∶30),流速为1.0 ml/min,检测波长为210 nm,柱温为35℃,进样量为5μl。结果苯扎氯铵含n-C12H25取代同系物、含n-C14H29取代同系物和苯扎溴铵在2 mg/L~700 mg/L、4 mg/L~400 mg/L和2 mg/L~1 000 mg/L线性关系良好,相关系数(r)均为0.999 9。检出限分别为0.2 mg/L、0.4 mg/L、0.2 mg/L,定量限分别为0.5 mg/L、1.0 mg/L、0.5 mg/L,回收率为98.83%~98.89%,相对标准偏差为0.3%~0.9%。结论本方法灵敏、准确、专属性及重复性好,可用于测定消毒液中苯扎氯铵和苯扎溴铵含量。     

HPLC法测定氯硝柳胺乙醇胺盐微乳含量

目的建立高效液相色谱-紫外检测器法测定氯硝柳胺乙醇胺盐微乳含量的方法。方法样品经甲醇稀释破乳后过滤,取续滤液,测定其中药物的含量。采用Zorbax Eclipse plus C18柱(250 mm×4.6 mm,5μm)为色谱柱,甲醇-水(1∶9,V/V,磷酸调节p H值至3.5)为流动相,流速为1.0 ml/min,检测波长为333 nm,柱温为30℃,进样量为10μl,用外标法对有效成分进行定量分析。结果氯硝柳胺乙醇胺盐的分离情况良好,在质量浓度为10μg/ml~100μg/ml时与峰面积呈良好的线性关系(r=0.999 9),低、中、高3种质量浓度的平均回收率分别为101.46%、99.79%、98.79%,相对标准偏差(RSD)分别为0.71%、0.42%、0.44%(n=3),3批载药微乳的平均含量为0.48 mg/ml。结论该方法准确,便捷,专属性好,适用于氯硝柳胺乙醇胺盐微乳的含量测定。     

液相色谱梯度洗脱法测定洗发类化妆品中的4种去屑剂

目的:建立液相色谱梯度洗脱法同时测定洗发类化妆品中的水杨酸、酮康唑、氯眯巴唑和吡罗克酮乙醇胺盐4种去屑剂。方法:采用C18柱,以乙腈-甲醇-0.01 mol/L的磷酸二氢钾溶液(含EDTA0.5 mol/L,磷酸调pH值至4.0)梯度洗脱分离各个组分,进样体积5μl,DAD检测器,检测波长230 nm。结果:水杨酸、酮康唑的线性范围为5μg/ml～500μg/ml,氯眯巴唑和吡罗克酮乙醇胺盐线性范围为10μg/ml～1000μg/ml,最低检出限分别为0.12μg/ml、0.19μg/ml、0.39μg/ml、0.98μg/ml。该方法精密度高,RSD在0.7%～1.5%之间,各组分加标回收率在98%～105%之间。结论:本方法具有操作简便、干扰小、快速等特点。     

液液萃取气相色谱法测定水中丙烯腈和乙腈

目的建立水中丙烯腈、乙腈测定的气相色谱方法。方法取500mL水样加氯化钠至饱和溶液,用乙酸乙酯和二氯甲烷(4:1)混合液提取浓缩,采用HP-INNOWAX色谱柱(60m×0.25mm,0.12μm)进行气相色谱法测定。结果在1.0～20.0μg/L的线性范围内,丙烯腈、乙腈的回归方程均呈较好的线性关系,r0.998。方法检出限均为0.4μg/L,丙烯腈、乙腈平均回收率分别为93.2%～95.0%和92.1～95.8%,RSD分别为2.1%～5.5%和3.4%～4.9%。结论该方法操作简单、分离度好、灵敏度和准确度均较高,可满足水中丙烯腈、乙腈的检测。     

高效液相色谱法测定早餐谷物中的烟酸和烟酰胺

目的建立高效液相色谱法同时测定早餐谷物中烟酸和烟酰胺含量的方法。方法样品经人工胃液在37℃水浴中放置过夜提取,放至室温,摇匀,离心,取上清液用0.45μm滤膜过滤,采用DIKMA Spursil C18色谱柱(4.6 mm×250 mm,5μm),以1-癸烷磺酸钠溶液(1.22 g→850 ml)-乙腈-磷酸(850∶150∶1,V/V)为流动相,柱温为30℃,体积流速为1.0 ml/min,进样量为20μl,通过二极管阵列检测器进行检测,检测波长为261 nm。结果烟酸和烟酰胺均在1μg/ml~100μg/ml时呈现良好的线性关系(r0.999),平均加标回收率为98.5%~102.6%,相对标准偏差(RSD)为2.3%~4.2%,方法的检出限分别为0.23 mg/kg、0.28 mg/kg。结论该方法操作简便,重现性良好,测定结果准确、可靠,可用于早餐谷物中烟酸和烟酰胺含量的同时测定。     

高效液相色谱法同时测定元素多维片中5种水溶性维生素

目的:建立反相高效液相色谱法同时测定多维元素片中烟酸、维生素B1、维生素B6、烟酰胺和维生素B2的方法。方法:Phenomenex C18色谱柱(150 mm×4.6 mm,5μm);0.05 mol/L磷酸二氢钾为流动相A,乙腈为流动相B,梯度洗脱;柱温:35℃;流速:0.8 ml/min;检测波长:265 nm。结果:烟酸、维生素B1、维生素B6、烟酰胺和维生素B2的线性范围分别为6.15~393.76μg/ml、6.44~412.32μg/ml、6.85~438.24μg/ml、6.46~413.12μg/ml和3.26~52.15μg/ml。平均回收率分别为:烟酸104.8%、维生素B1 99.7%、维生素B6 95.3%、烟酰胺103.4%和维生素B296.9%。结论:本方法同时测定5种维生素,具有快速、简便、准确的特点。     

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。     

高效液相色谱法同时测定糕点中山梨酸和纳他霉素

目的建立同时测定糕点中山梨酸和纳他霉素的高效液相色谱法。方法糕点中的山梨酸和纳他霉素经乙酸铵-甲醇(2∶1,V/V)溶液超声提取、过滤后进样测定。采用C18色谱柱,以0.1%的三氟乙酸水溶液及含0.1%三氟乙酸的乙腈-四氢呋喃(5∶1,V/V)为流动相进行梯度洗脱,流速为1.0 ml/min,检测波长为280 nm,柱温为30℃。结果山梨酸和纳他霉素的浓度范围分别为0.446μg/ml~89.28μg/ml和0.297 6μg/ml~59.52μg/ml时,其线性相关系数均为0.999 8,方法的回收率分别为93.6%~99.0%和92.2%~95.1%,检出限分别为0.02μg/ml和0.15μg/ml。结论该方法快速、简便、重现性好,结果准确可靠,适用于糕点中山梨酸和纳他霉素的同时测定。     

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.     

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.