离子色谱法快速测定牛奶中硝酸盐

目的　建立用离子色谱法测定牛奶中硝酸盐含量的方法。方法　样品用3%乙酸和1mol/LKOH溶液脱去蛋白质和脂肪等有机物,再通过Sep PakC18小柱预处理后,进行离子色谱法测定,色谱柱为DIONEXIonpacAS14 4mm ,以3 5mmol/LNa2 CO3 / 1 0mmol/LNaHCO3 为淋洗液,流速为1 2ml/min ,抑制电流:5 0mA ,电导检测。结果　该方法硝酸盐在2 μs量程档线性范围是0 1～1 0mg/L ,在10 μs量程档线性范围是1 0～15 0mg/L ,相关系数均大于0 999。最低检出限为0 0 0 13mg/L ;回收率在98%～10 6 %之间;样品测定相对标准偏差为3 37%。结论　离子色谱法操作方便、准确、重现性好,快速测定牛奶中硝酸盐含量具有应用价值     

离子色谱法同时测定牙膏中的单氟磷酸盐与游离氟的研究

目的:采用离子色谱法同时测定牙膏中单氟磷酸盐与游离氟的含量。方法:色谱柱为DIONEXIonpacAS14 -4mm,以2. 0mmol/LNa2CO3 /2 5mmol/LNaHCO3 为淋洗液,流速为1. 2ml/min,抑制电流: 50mA,电导检测。结果:该方法游离氟F-与单氟磷酸盐MFP2-线性范围分别为0. 1~10 .0mg/L, 0. 5~50mg/L,相关系数均大于0 999(n=5);最低检测限分别为2. 6×10-5 mg/L, 1 3×10-4 mg/L;样品测定相对标准偏差分别为1 66%, 0 79%;回收率分别为93 .0% ~102. 0%, 102 .9% ~106 .4% 之间。结论:该方法操作简便,能同时测定牙膏中游离氟与单氟磷酸盐的含量,具有准确、快速等特点。     

离子色谱法测定饼干中乙二胺四乙酸铁钠方法研究

目的:研究用离子色谱法测定饼干中乙二胺四乙酸铁钠的可行性。方法:美国Dionex公司DX-120型离子色谱仪,ION Pac As14 4×250 mm分析柱,CDM-3电导检测器,2 mmol/L Na2CO3溶液,流速为0.82 ml/min,以保留时间定性,峰面积定量。结果:乙二胺四乙酸铁钠的最低检出限为10 mg/L;标准在10 mg/L～60 mg/L范围线性良好,相关系数为0.9990;RSD%为0.55%～0.65%;回收率为90%～97%。结论:采用离子色谱法测定饼干中乙二胺四乙酸铁钠的含量是具有分析时间短,准确度高,适合于饼干中乙二胺四乙酸铁钠含量的测定。     

过硫酸钾消解-离子色谱法测定水和废水中总磷

目的:建立离子色谱法测定水中总磷的方法。方法:采用MetrosepASupp5 -250分离柱,Na2CO3 /NaHCO3 =3. 2 /1 .0mmol/L淋洗液,抑制型电导检测器。结果:检测器量程为50μs/cm时,线性范围为0. 05 ~5 .0mg/L,相关系数大于0. 999(n=5),检出限1 3μg/L(以P计),样品加标回收率在94 .65% ~104. 8% 之间,RSD<5. 0 %。结论:方法简便、灵敏、准确,可用于水和废水中总磷的分析。     

离子色谱法同时测定水中的四种阴离子的研究

目的建立离子色谱法同时测定水中F-、Cl-、SO42-和NO3-离子。方法采用免试剂离子色谱仪系统,淋洗液全自动发生,选择30mmol/L KOH为淋洗液,流速1·2ml/min。结果测定方法相关系数大于0·9998,线性范围宽,精密度RSD<2·02%,准确度好。结论方法简便、快速,无干扰,灵敏度高,适用于水中4种阴离子同时测定。     

离子色谱法测定化妆品中巯基乙酸的研究

目的　建立离子交换—抑制电导检测色谱法分离测定化妆品中的巯基乙酸。方法　采用高容量阴离子色谱柱IonPac AS1 1 HC ,以 2 5mmol LNaOH +1 %甲醇为淋洗液 ,流速 0 85ml min。样品经三氯甲烷去除部分有机物后 ,进样分析。结果　方法的线性范围广 ,精密度和准确度高 ,相对标准偏差RSD(% ) <0 94 1 ,样品平均加标回收率 91 5 %～ 1 1 0 0 % ,检出限为 2 3mg kg。结论　样品的酸度、共存离子及淋洗液中甲醇对测定无影响。本方法简便、准确可靠 ,适用性好     

工作场所空气中甲酸的离子色谱测定法

目的 建立工作场所空气中甲酸的硅胶管采集离子色谱测定法.方法 甲酸经硅胶管采集,20 mmol/L KOH溶液解吸,离子色谱法测定.结果 进样量25 μl,甲酸浓度在0～25.0 mg/L范围内具有良好的线性关系,方法的相对标准偏差为0.6%～1.2%,加标回收率为98%～103%,测定范围为0.8～83.3 mg/m3.结论 该方法适用于工作场所空气中甲酸的测定.     

灰化-离子色谱法测定茶叶中总氟的研究

目的建立灰化一离子色谱法测定茶叶中总氟的方法。方法样品经灰化处理后,用离子色谱法测定。淋洗液为1．8mmol／LNa2CO3-1.7mmol／LNaHCO3。结果相对标准偏差（RSD）为0．53％,回收率为97．2％～97．4％,最低检出浓度为0．5mg／kg。结论用灰化一离子色谱法测定茶叶中总氟,方法便捷、灵敏度高、精密度好、回收率高、结果可靠。     

蚁安康胶囊中蚁酸的离子色谱法测定方法的研究

目的:研究用离子色谱法测定蚁安康胶囊中蚁酸(甲酸)的可行性.方法:美国Dionex公司DX-120型离子色谱仪,ION Pac Asl4 4×250 mm分析柱,CDM-3电导检测器,0.56 mmol/L NaHC03溶液,流速为1.2 ml/min,以保留时间定性,峰面积定量.结果:甲酸的最低检出限为0.0142 mg/L;标准在1.0～8.0 mg/L范围线性良好,相关系数为0.9993;RSD%为0.575～0.713;回收率为91.00%～99.62%.结论:采用离子色谱法测定蚁安康胶囊中甲酸的含量是具有分析时间短,准确度高等优点,适合于蚁安康胶囊中甲酸含量的测定.     

反相高效液相色谱法同时测定膳食补充剂中维生素C、叶酸和泛酸的方法研究

采用反相高效液相色谱法 ,对膳食补充剂中的维生素C、叶酸、泛酸的同时测定进行了方法学研究。色谱参考条件为SupelcosilC18柱 ;柱温 :4 0℃ ;检测波长 :2 10nm ;流动相 :0 .0 5mol/LKH2 PO4∶CH3 OH∶0 .1mol/LKOH =85 +8+7(pH6 .3) ;流速 :1.5ml/min。用外标法定量 ,线性范围为维生素C :0～ 1.0mg/ml;叶酸 :0～ 0 .1mg/ml;泛酸 :0～ 0 .2 5mg/ml。线性相关系数为 0 .999到 0 .9997,平均回收率为 90 .5 %～ 10 5 .6 % ,相对标准偏差为 1.6 %～ 8.0 %。方法简便 ,快速、准确 ,用于实际样品测定 ,结果令人较为满意。     

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.