高效液相色谱法测定化妆品中过氧化氢的方法研究

〔目的〕用高效液相色谱法测定化妆品中过氧化氢。〔方法〕将被测样品中的过氧化氢与三苯基膦进行衍生化反应 ,生成氧化三苯基膦 ,用高效液相色谱法进行分析定量。〔结果〕方法的相关性好 (γ >0 .9990 ) ,样品测定的相对标准偏差RSD <5 % ,加标回收率为 99.3 %～ 10 3 .7% ,检出限为 1.7× 10 -5mol/L。〔结论〕本方法线性范围宽 ,测定结果准确 ,适用于化妆品中过氧化氢的常规分析。     

饮料、糖果等食品中六种食用色素的连续示波极谱测定方法

对于食品中添加的食用色素的测定 ,ＧＢ/Ｔ5 0 0 9.35 - 96中规定了两种测定方法 :高效液相色谱法和薄层色谱 (纸色谱法 ) 〔1〕,前者需要液相色谱仪 ,后者测定方法操作复杂、定量麻烦 ,而且两种方均需对样品进行提取纯化 ,去除干扰物质后才能测定。示波极谱法测定食用色素的方法也见报道 ,如氨水一氯化铵 (ｐＨ8- 9)用于测定汽水、糖果中胭脂红〔2〕、汽水果汁中日落黄〔3〕、苋菜红、靛蓝〔4〕,盐酸—三乙醇胺体系用于测定亮蓝〔5〕,乙酸一乙酸钠 ,(ｐＨ3.6 )测定汽水果汁中亮蓝〔6〕,磷酸二氢钾—磷酸氢二钾用于测定汽水糖果中的柠檬黄、…     

保健食品中红景天甙的提取和测定方法研究

〔目的〕建立保健食品中红景天甙样品的前处理和高效液相色谱检测方法。〔方法〕保健食品中的红景天甙经 70 %乙醇超声波提取 ,聚酰胺柱净化后 ,以甲醇 -0 .0 1mol LNH4 Ac为流动相 ( 2 0∶80 ) ,用C1 8柱 ,紫外 2 15nm检测。〔结果〕优化了含红景天保健食品中红景天甙的提取、净化和测定条件 ,有效去除样品中的干扰成分 ,定量检测红景天甙。方法检出限为 0 .5 μg ml,样品测定的相对标准差 (RSD)小于 2 .5 % ,加标回收率为 97.1% -10 2 .4%。〔结论〕本方法操作简便 ,灵敏、可靠 ,适用于红景天原料和保健食品中红景天甙的分析测定。     

食品中致癌物丙烯酰胺的固相萃取-高效液相色谱联用测定方法

目的　研究检测食品中致癌物丙烯酰胺的固相萃取 -高效液相色谱测定方法。方法　用水提取食品中丙烯酰胺 ,采用固相萃取小柱对样品液进行纯化 ,以二极管阵列高效液相色谱法测定其含量。结果　方法检出限为 10ng/g ,回收率在大于 95 %之间 ,精密度为 5 3 4% (低浓度 )、3 40 % (中等浓度 )和 4 3 0 % (高浓度 )。满足了我国“十五”国家重大科技专项“食品安全关键技术”课题有关建立食品中丙烯酰胺测定方法要求。结论　建立的方法测定食品中丙烯酰胺满足痕量分析要求 ,并具有操作简单、干扰少、快速、准确可靠等特点 ,可用于我国食品中丙烯酰胺状况调查     

固相萃取高效液相色谱法测定油炸食品中丙烯酰胺

目的:建立固相萃取高效液相色谱法测定油炸食品中丙烯酰胺的新方法。方法:用水提取食品中的丙烯酰胺,采用固相萃取小柱对样品液进行纯化,用高效液相色谱法测定其含量。结果:方法检出限为4.8 ng/g,加标回收率在88.7%~101.0%之间,RSD分别为3.3%(低浓度),3.2%(中浓度)和4.2%(高浓度)。结论:该方法操作简单、干扰少,准确可靠,用于实际样品中丙烯酰胺的检测,结果满意。     

高效液相色谱法测定蛋黄中苏丹I～IV及对位红

〔目的〕建立高效液相色谱(HPLC)快速测定蛋黄中苏丹红、对位红的方法。〔方法〕蛋黄样品经乙腈提取、超声波萃取,提取液经离心、过滤后的样液经高效液相色谱紫外—可见光检测器测定,外标法定量。〔结果〕该方法在0.2mg/kg～2.0mg/kg范围内添加回收率为97.0%～102%,变异系数小于5.0%,最低检出浓度为0.05mg/kg。〔结论〕方法具有高效、快速、稳定的特点,能满足日常检验工作的需要。     

气相色谱法测定食品中甜蜜素

甜蜜素又名环己基氨基磺酸钠 (C6H12 NNaO3 S) ,是一种复合食品添加剂 ,用作甜味剂的一种。国家卫生标准GB2 76 0- 1996规定其使用限量为 0 6 5～ 8 0g/kg〔1〕。目前 ,已报道的测定方法有气相色谱法〔2〕、液相色谱法〔3〕、比色法〔4〕、薄层色谱法〔4〕。但所用的样品处理方法对大批量食品样品的测定效果不佳。本文根据实际情况 ,改进样品处理方法及提取剂 ,采用NaOH -CuSO4沉淀体系预处理样品 ,CCl4提取 ,气相色谱法测定。方法简便快速、灵敏准确、可靠 ,适用于多种食品样品的测定。1　实验部分1 1　实验原理　在硫酸介质中环己…     

保健食品中淫羊藿苷测定方法研究

〔目的〕研究保健食品中淫羊藿苷的测定 ,并比较紫外分光光度计法与高效液相色谱法的测定效果〔方法〕采用经乙酸乙酯萃取 ,并经大孔树脂分离提纯 ,分别对固体粉状试样、含油软胶囊试样、口服液试样用二种不同的方法测定淫千藿苷的含量。〔结果〕经问收率试验和实际样品检测 ,方法的回收率分别为 93.0 %～ 98.0 % ,95 .0 %～ 99.0 % ,实际样品测定RSD分别为 1.2 1%～3.37% ,1.2 9%～ 3.92 %。〔结论〕二种方法测定的结果均较为满意 ,可根据实验室条件自行选择 ,但紫外分光光度计更适用于检测成分比较单一的试样。     

反相高效液相色谱法同时测定广州部分地区肉类4种抗生素的残留量

〔目的〕高效液相色谱法同时测定肉类中磺胺嘧啶 (SD)、磺胺二甲基嘧啶 (SMZ)、土霉素 (OTC)、磺胺甲恶唑(SN2 )抗生素的残留量。〔方法〕色谱柱为ODS -C1 8,以 2mmol L醋酸铵 :乙腈 :80 :2 0 (pH =2 .0 3 )为流动相 ,流速 0 .8ml/min ,486紫外检测器 ,检测波长为 2 70nm。〔结果〕该方法各抗生素的线性范围均为 0 .0 1～ 1.0 μg/ml ,相关系数均为 0 .99以上 (n =5 ) ;最低检测限为 0 .0 1μg/ml;回收率均为 95 .6%～ 10 6.0 % ;日内、日间变异系数均在允许范围内 (小于 15 % )。〔结论〕该方法操作简便 ,是动物性食品残留抗生素的快速而准确的检测方法。     

高效液相色谱质谱测定肉品中的磺胺二甲嘧啶

〔目的〕用高效液相色谱电喷雾质谱 (ESI -MSn)测定肉品中的磺胺二甲嘧啶。〔方法〕通过多级质谱对阳性样品确证。〔结果〕以二级碎片做定量离子 ,磺铵二甲嘧啶测定线性范围为 (2 5～ 40 0 ) μg L ,最低检出浓度为 5 μg L。〔结论〕方法简便快速 ,检出限低。     

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.     

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.     

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.     

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.