酶联免疫分析法测定水产品中氯霉素残留量

目的:建立测定水产品中氯霉素残留量的ELISA分析法。方法:对不同样品采用不同的前处理方法,用ELISA方法进行检测。结果:方法检测限为0.01μg/kg;在0.5μg/kg和2.0μg/kg两个添加水平,样品加标平均回收率分别为72%～116%和86%～108%;重复性实验:RSD分别为1.8%～6.2%和6.5%～7.8%;重现性实验RSD分别为3.8%和5.9%。结论:本方法灵敏度、准确度和精密度均符合残留分析质量控制的要求,适用于水产品中氯霉素残留量的快速检测。     

液相色谱-串联质谱法测定常见食品中磺胺及喹诺酮

[目的]本试验研究建立常见17种磺胺和15种喹诺酮类药物残留量的液相色谱-电喷雾串联离子阱质谱测定方法。[方法]以稳定同位素氘代磺胺邻二甲氧嘧啶、氘代磺胺间二甲氧嘧啶作为内标,采用多反应监测定量。样品经过匀浆、超声波提取、甲醇溶液涡旋溶解残留物、正己烷涡旋混合离心后进行液相色谱-质谱分析。采用C18柱,MGⅡ色谱柱,以均含0.1%甲酸的水和甲醇、乙腈为流动相进行梯度洗脱。[结果]17种磺胺和15种喹诺酮类药物的线性范围为2.0~50μg/kg,相关系数r>0.995,平均回收率为83.3%~109.9%(添加水平为2.5~10μg/kg),相对标准偏差为2.1%~8.1%。本方法最低检出限均为2.0μg/kg,最低定量限均为4.0μg/kg。[结论]所建方法简便、快速、干扰少、特异性强,是磺胺和喹喏酮残留检测的理想方法。     

2018年江苏部分地区流通环节水产品中麻醉剂和多种抗生素残留监测

目的对江苏部分地区流通环节水产品中麻醉剂及抗生素残留进行监测。方法2018年8-9月采集26类108批水产样品,采用国家标准和文献方法对样品中丁香酚和间氨基苯甲酸乙酯甲磺酸盐(tricaine methanesulfonate,MS-222)两种麻醉剂及恩诺沙星、磺胺总量、硝基呋喃、氯霉素四类兽药残留量进行检测。结果丁香酚检出率为18.52%(20/108),含量范围为2.02~297.78μg/kg;恩诺沙星检出率为28.70%(31/108),含量范围为1.42~1340.36μg/kg,其中不合格4批;呋喃西林代谢物氨基脲检出率为1.85%(2/108),含量范围为13.21~20.60μg/kg;磺胺总量检出率为1.85%(2/108),含量范围为4.82~17.21μg/kg,未超标;氯霉素和MS-222均未检出。结论2018年江苏部分地区流通环节水产品中存在违规使用麻醉剂丁香酚情况,恩诺沙星在水产品中应用广泛且有残留量超标现象,禁用药物呋喃西林仍有非法使用问题,磺胺总量、氯霉素和MS-222检测结果总体良好。     

高效液相色谱法测定水产品中泰乐菌素残留量

目的:建立水产品中泰乐菌素残留量的高效液相色谱测定方法。方法:样品在碱性条件下用乙酸乙酯提取,提取液旋转蒸干后,经正己烷脱脂,SCX柱固相萃取净化,乙腈与磷酸盐缓冲液为流动相梯度洗脱,外标法定量。结果:泰乐菌素在0.050μg/ml～5.00μg/ml内呈良好线性关系,相关系数r=0.9998。检出限为30μg/kg,定量限为100μg/kg。在50μg/kg～500μg/kg添加水平下回收率为72.4%～106%,相对标准偏差均小于10%。结论:该方法的灵敏度和重复性均满足水产品中泰乐菌素药物残留量检测需要。     

柱前衍生HPLC-FLD法测定水产品中3种麻痹性贝类毒素

目的建立水产品中3种麻痹性贝类毒素成分(GTX2,3、dcSTX和STX)的柱前荧光衍生高效液相色谱(HPLC-FLD)检测方法。方法样品用1%乙酸提取,C18固相萃取柱净化,2%H2O2荧光衍生,以Symmetry?C18柱(4.6mm×150mm,5μm)为色谱柱分离,以乙腈和0.1mol/L甲酸铵(595)作为流动相,流速1.0mL/min,荧光检测器激发波长340nm,发射波长395nm。结果该法在10~500μg/L范围内线性关系良好,平均加标回收率为72.5%~88.6%,RSD为2.8%~4.7%。方法的检出限分别为dcSTX 3μg/kg、STX 10μg/kg和GTX2,34μg/kg。结论本方法灵敏度高、结果可靠,为检测水产品贝类麻痹性毒素的含量提供了一种高效便捷的方法。     

水产品中呋喃唑酮代谢物残留量的酶联免疫分析

目的对酶联免疫分析试剂盒测定水产品中呋喃唑酮代谢物（AOZ）残留量的方法进行改进。方法采用标准溶液与样品同时衍生化后用酶联免疫分析法检测，并用LC—MS—MS方法对比验证。结果ELISA方法检测限为0．2μg/kg；样品平均加标回收率：在0．5μg/kg添加水平为99．0％，在1．0μg/kg添加水平为88．2％；RSD为9．18％～17．8％。实际样品对照实验显示：AOZ值0．5μg/kg时，ELISA与LC-MS-MS的测试结果完全一致，无假阴性结果；AOZ值〉8．1μg/kg时，两法结果一致；1．0μg/kg〈AOZ值〈8．1μg/kg时，其EUSA与LC-MS-MS的结果相对误差〈30％。结论该方法适合于一次性大批量水产品中AOZ残留量的快速筛选。     

2012年鞍山市水产品中喹乙醇代谢物残留量监测分析

目的开展水产品中喹乙醇代谢物残留量的监测分析,保障水产品的食品安全。方法随机在鞍山市本地农贸市场河鱼批发部采集淡水鱼类,采用《水产品中喹乙醇代谢物残留量的测定高效液相色谱法》（农业部1077号公告-5-2008）进行喹乙醇代谢物残留量检测。结果 MQCA在0.005～1.000μg/ml范围内,线性关系良好,r=0.999 3;高、中、低3种浓度的加标样品平均回收率分别为76.5%、85.1%、95.4%;相对标准偏差（RSD）分别为9.40%、5.66%、4.31%;本方法最低检出限为4μg/kg。对黑鱼、鲢鱼、草鱼、泥鳅、眼眶鱼、鳝鱼、嘎鱼、鲫鱼、鲤鱼、武昌鱼、鲶鱼等水产品进行喹乙醇代谢物MQCA的含量测定,在所检样品中均未检出喹乙醇代谢物。结论有效落实食品安全风险监测工作计划,为卫生监督和防控提供科学依据。     

HPLC法测定肉中五种磺胺兽药残留量及其不确定度评估

〔目的〕建立肉中 5种磺胺兽药残留量测定方法。〔方法〕采用高效液相色谱 (HPLC)梯度洗脱法同时测定肉中磺胺嘧啶、磺胺二甲嘧啶、磺胺 - 5 -甲氧嘧啶、磺胺二甲氧嘧啶、磺胺喹恶啉残留量。使用Capcell-pakC18柱 (SHISEI DO) ,以乙腈和 1% (V/V)乙酸溶液为流动相 ,使用紫外检测器 ,在 2 70nm处对样品中 5种磺胺兽药进行检测。〔结果〕磺胺嘧啶、磺胺二甲嘧啶、磺胺 - 5 -甲氧嘧啶、磺胺二甲氧嘧啶、磺胺喹恶啉分别在 0 196 μg/ml～ 1 96 4 μg/ml,0 199μg/ml～1 992 μg/ml,0 2 2 0 μg/ml～ 2 2 0 4 μg/ml,0 188μg/ml～ 1 884 μg/ml,0 2 0 4 μg/ml～ 2 0 36 μg/ml范围内有良好的线性关系 ,其线性相关系数分别为r=0 9989,r=0 9990 ,r=0 9993,r=0 9993和r=0 9991;回收率在 72 2 3%～ 93 75 %。〔结论〕该方法专属性强、灵敏可靠、重现性好。     

高效液相色谱-荧光法同时检测水产品中阿维菌素和伊维菌素

目的建立了水产品中阿维菌素(abamectin, ABA)和伊维菌素(ivermectin, IVM)的高效液相色谱-荧光检测方法。方法样品经乙腈提取,正己烷除脂后,氮气吹至近干,加入衍生化试剂三氟乙酸酐和N-甲基咪唑室温衍生15 min,甲醇定容。采用甲醇/乙腈/0.4%乙酸溶液三元梯度洗脱,基质工作曲线法定量检测。结果在23 min色谱保留时间内阿维菌素和伊维菌素得到有效的分离。添加水平为4μg/kg、8μg/kg和20μg/kg的平均回收率为88.2%～107.5%,相对标准偏差(RSD)为1.4%～9.6%,阿维菌素和伊维菌素的定量限均为3μg/kg。应用该方法对水产品中的阿维菌素和伊维菌素进行测定,5批次样品均未检出。结论本法前处理过程简便高效,方法灵敏度和准确度均满足实际样品的检测需求,适用于大批量水产品中阿维菌素和伊维菌素残留量的检测。     

宁波市鲜活水产品抗生素残留调查研究

目的：系统了解宁波市市售鲜活水产品中抗生素的残留现状。方法：随机选择35个采样点,共采集230份样品,采用液相色谱或ELISA方法进行抗生素检测。结果：氯霉素检出范围0-0.31μg/kg,超标率5.2%;土霉素检出范围0-6 300μg/kg,超标率22.2%;金霉素检出范围0-2 300μg/kg,超标率50.4%;四环素检出范围0-1 300μg/kg,超标率23.5%;恩诺沙星检出范围0-322.1μg/kg,超标率6.5%;诺氟沙星检出范围0-49.33μg/kg,无超标;氟苯尼考检出范围0-23.07μg/kg,无超标;呋喃唑酮检出范围0-6.2μg/kg,无超标;磺胺（总）检出范围0-256.5μg/kg,超标率1.3%。各抗生素在海水养殖产品中超标率高于淡水养殖产品。结论：宁波市市售鲜活水产品存在部分抗生素残留超标,海水养殖产品中超标情况尤为严重,需要加强水产品养殖、销售的管理。     

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.