氢化物原子荧光法测定保健食品中总硒含量方法的研究

目的研究应用AFS—230原子光谱仪对保健食品中无机硒、有机硒含量的测定方法,为简便、快捷测定食品中硒提供依据。方法保健食品经硝酸-高氯酸消解后,使用原子荧光谱仪测定样品中的总硒,条件为炉高8.0mm,灯电流40mA,负高压300V,原子化温度200℃,载气流速300m l/m in,屏蔽气流速700 m l/m in。结果本法检出限为0.2ng/m l,回收率高含量为91.1%~98.4%,低含量的为87.1%~103.9%。其他共存金属不产生干扰。结论本法操作简单,快速准确,适用于保健食品中总硒的测定。     

高效液相色谱-蒸发光散射检测法测定保健食品中的磷脂酰丝氨酸

目的建立保健食品中的磷脂酰丝氨酸含量的高效液相色谱分析方法。方法样品采用三氯甲烷溶剂提取,经过离心后,取上清液过0.45μm滤膜,进样10.0μl,采用Diol色谱柱作为分析柱,柱温箱温度:35℃,梯度洗脱;设定蒸发光检测器氮气压力为280 Pa,漂移管温度80℃,加热器级别60%,进行检测。结果在25μg/ml~1 000μg/ml浓度范围内,高效液相色谱的蒸发光检测器的响应值与保健食品中磷脂酰丝氨酸的含量呈对数线性相关,相关系数r为0.999 2,线性方程为y=1.669 9x+0.021 7。加标回收率为92.4%~99.2%,相对标准偏差3.0%,检出限为7.5μg/ml。结论该法样品前处理简单,无需衍生反应,准确度高,重复性好,可对保健食品中的磷脂酰丝氨酸进行快速准确的分析检测。     

UPLC法测定保健食品中人参皂甙Rg1和Re的研究

目的:采用WATERS超高效液相色谱法测定保健食品中人参皂甙Rg1和Re的含量。方法:样品用甲醇超声波提取法提取,采用ODS-C18(2.1 mm*100 mm,1.7μm)色谱柱,20%乙腈水溶液为流动相,0.3 ml/min流速对人参皂甙Rg1和Re洗脱,用DAD检测器在203 nm提取定量分析。结果:测定两种人参皂甙的相对标准偏差为0.9%~4.4%,最低检出浓度0.005 mg/kg,回收率91.0%~108.9%。结论:方法快速、节约,适用于保健食品中人参皂甙Rg1和Re含量的测定。     

保健食品中镁的火焰原子吸收光谱测定法

目的建立火焰原子吸收光谱法测定保健食品中镁的分析方法。方法样品用硝酸和高氯酸消化后,导入火焰原子吸收分光光度计中,与标准系列比较定量。结果方法的检出限为0.017μg/m l,相对标准偏差为0.72%~1.86%,加标回收率在96.9%~104.6%之间。结论该法操作简便、快速、准确,适用于保健食品中镁的测定。     

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。     

超高效液相色谱法测定保健食品中木香烃内酯和去氢木香烃内酯

目的利用超高效液相色谱技术,建立保健食品中木香烃内酯和去氢木香烃内酯含量的检测方法。方法样品经甲醇提取,采用ACQUITY UPLC BEH C18色谱柱(2.1 mm×50 mm,1.7μm),以乙腈-水(40∶60,V/V)为流动相,紫外检测器波长为225 nm,流速为0.5 ml/min,进样体积为5μl,柱温为30℃,通过超高效液相色谱分离,以外标法定量。结果木香烃内酯和去氢木香烃内酯的浓度为0μg/ml~1 000μg/ml时,标准曲线的线性关系良好,线性相关系数为0.999 9。相对标准偏差(RSD)为0.5%~3.7%,加标回收率分别为96.2%~100.6%、96.2%~103.9%。结论本方法具有灵敏度高、选择性好、精密度和准确度好等优点,而且更快捷,适合保健食品的日常检测工作。     

HPLC柱前衍生测定保健食品中牛磺酸含量

目的:建立高效液相色谱法测定保健食品中牛磺酸含量的测定方法。方法:采用ZORBAX Bonus-RP色谱柱(5μm,4.6 mm×150 mm),以甲醇+水=20+80为流动相,流速1.0 m l/m in,波长330 nm,柱温为25℃,在柱前进行衍生反应后直接进样。结果:线性范围:30.3~252.0 ng,r=0.9997(n=8)。加标回收率98.3%~101.7%。最低检测限(S:N=3)为4.1 ng。最低定量限(S:N=10)为13.7 ng。结论:本法测定条件下所用色谱柱对测定组分专一性较好,简便快速,定量准确,灵敏度高,重现性好,适用于保健食品中牛磺酸的测定,可作为产品的质量控制方法。     

高效液相色谱法-蒸发光散射检测器测定保健食品中大豆异黄酮

目的:建立一种同时测定保健食品中的4种大豆异黄酮D、G、De、Ge的蒸发光散射检测器高效液相色谱法。方法:色谱柱:Crom asail 200×4.6 mm 5μm的C18柱,流动相:甲醇-水梯度洗脱,流速1.0 m l/m in,ELSD:撞击器关,雾化器气体流速2.7 L/m in,漂移管温度104℃。样品经研磨后,用80%甲醇水溶液超声提取30 m in,定容离心后过0.45μm滤膜,进样20μ。l测定时间只需15 m in左右,D、G、De、Ge分离良好。结果:梯度洗脱基线平直,线性范围2.6~150μg/m l,D、De、G、Ge的相关系数分别为0.9999、0.9994、0.9999、0.9996,加标回收率:89.7%~103.2%,RSD在1.2%~5.5%之间。结论:本方法前处理简便、准确、快速,可作为同时测定4种大豆异黄酮含量的方法。     

空气中亚硝酸盐和硝酸盐的离子色谱测定方法的研究

目的:建立空气中亚硝酸盐和硝酸盐的离子色谱测定方法。方法:本文采用超细玻璃纤维滤纸采集空气中亚硝酸盐和硝酸盐,用蒸馏水洗脱过滤后,经色谱柱分离,电导检测器检测,保留时间定性,峰高或峰面积定量。结果:空气中亚硝酸盐和硝酸盐的线性范围分别为0.5~30.0μg/m l和0.5~30.0μg/m l;相关系数分别为0.9997和0.9992;方法的最低检出限分别为0.5μg/m l和0.5μg/m l;若采集300 L空气进行测定,则最低检出浓度分别为0.017 mg/m3和0.017 mg/m3;相对标准偏差分别为0.39%~1.03%和0.45%~1.00%;样品洗脱效率分别为100.4%~103.2%和102.3%~106.8%;采样效率分别为94.8%~100.0%和92.7%~94.6%;样品在室温中至少可保存1周。结论:此法灵敏度高,选择性好,干扰少,是同时检测空气中亚硝酸盐和硝酸盐的好方法。     

气相色谱-质谱法快速测定面粉中过氧化苯甲酰

目的:建立快速测定面粉中过氧化苯甲酰的定性定量测定方法。方法:采用改进的前处理方法,用气相色谱-气质联用仪进行定性定量分析。结果:过氧化苯甲酰的方法最低检出限为0.5μg/m l,其在2.5~500μg/m l范围内呈线性关系,相关系数大于0.9995,RSD小于5%,回收率为95.8%~102.5%之间。结论:本法灵敏度高,操作简单,稳定性和重复性好,适合测定面粉中过氧化苯甲酰含量的检测。     

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.