A sensitive enzyme‐linked immunosorbent assay amplified by biotin–streptavidin system for detecting non‐steroidal anti‐inflammatory drug ketoprofen

A sensitive biotin–streptavidin‐amplified enzyme‐linked immunosorbent assay (BA‐ELISA) method was developed for detecting non‐steroidal anti‐inflammatory drug ketoprofen. Compared with traditional ELISA method, the sensitivity of proposed immunoassay was enhanced by the biotin–streptavidin system. Under the optimal condition, the median inhibitory concentration (IC₅₀) was 0.25 ng mL^?1, with minor cross‐reactivity to a number of structural analogs. This developed assay was successfully applied to detect the ketoprofen residues in different fish samples, and good recoveries (72.6–105.5%) were obtained. The results indicated that this immunoassay method could specifically detect trace ketoprofen residues and could be widely used for routine monitoring of food samples.     

辐射热流作用下树叶样品的燃烧特征研究

研究植物叶样在外部热辐射和值班火源作用下的燃烧现象特征并探索其成因和物理及化学本质。采用锥形量热仪开展实验,热辐射强度分别设定为35kW m-2、55kW m-2、70kW m-2和85kW m-2。实验样品为针阔叶树种共13种,其含水率在45%至79%间变化。实验表明,样品表现出不同的着火模式,有的为明火,有的则为阴燃,取决于树种和设定的辐射强度。样品出现有焰燃烧现象的最低热释放速率峰值(PHRR)在22.3kW m-2至35.6kW m-2之间,反映了形成气相火焰所需最低挥发分质量流率。气相产物CO2产生速率的峰值与PHRR呈高度线性性,表明了不同样品间气相燃烧或固相表面氧化(阴燃燃烧)反应的相似性。进一步分析表明,出现的独特热释放速率尖锐峰形是样品分层特性以及树叶的物理属性和热物性共同作用的结果。具有热薄特性的样品表层,在实验初期是接受外部辐射热的主体,其热解的产物是形成气相火焰的物质来源;在其转变为焦炭层后,对辐射热流向内层的渗透具有阻挡作用。建立起来的认识对于评估分层样品的燃烧性有一定的指导意义。     

A Comparison of the Precipitation Chemistry Measurements Obtained by the CAPMoN and NADP/NTN Networks

Precipitation chemistry measurementsobtained by the Canadian Air and PrecipitationMonitoring Network (CAPMoN) and the U.S. NationalAtmospheric Deposition Program/National Trends Network(NADP/NTN) have been examined using more than 7 yrof collocated data from two sites, namely, Sutton,Quebec, Canada and State College, Pennsylvania, U.S.A.In the case of the CAPMoN data, weeklyprecipitation-weighted mean concentrations, totalsample depths and total standard gauge depths werecomputed from daily data and compared to thecorresponding weekly sampling data of the NADP/NTNnetwork. Seasonal and annual precipitation-weightedmean concentrations and deposition values were alsocomputed for both networks and compared. Statisticallysignificant between-network biases were found to existin the weekly results for most of the measuredvariables, particularly standard gauge depth, sampledepth, pH, H⁺, NO₃ ^-,NH₄ ⁺,Na⁺; the NADP/NTN values were consistently lowerthan those of CAPMoN with the exception of pH andNa⁺. The magnitude of the biases was less than35% of the median CAPMoN weekly value for the 7 yr. For most of the measured parameters, thevariability of the between-network differencesrepresented less than 20% of the median CAPMoN weeklyvalue. Both the between-network biases andvariabilities were functions of several physicalparameters, the most dominant being the sample depthand the ionic concentration. For seasonal and annualdeposition values, statistically significantbetween-network biases were found for H⁺,SO₄ ^2-, NO₃ ^-,Ca²⁺,NH₄ ⁺ for both periods; for Mg²⁺ andK⁺ for seasonal data; and Cl^- for yearlydata, with the NADP/NTN deposition values being lowerthan those of CAPMoN. The relative biases ranged from7 to 37%. Part of the between-network bias in thedeposition estimates was directly attributable to astrong bias in the standard gauge depths of the two networks.     

离子色谱法测定水中无机阴离子水样的预处理

本文介绍了用离子色谱法测定无机阴离子，对污染严重的水样通常采用预处理柱法。论述了预处理柱的制备、再生，测定了预处理柱对重金属及有机物的去除率及无机阴离子的回收率。     

环境水样中双酚A的HPLC检测探讨

研究探讨了各种水化学条件（pH值、离子强度、共存阴离子、共存有机质）对高效液相色谱法（HPLC）检测模拟环境水样中微量双酚A的影响.采用高效液相色谱法检测水样中双酚A的标准曲线线性相关系数高（R2 ＞0.999）,在0.1～5 mg/L的双酚A浓度范围内呈现线性.本研究采用的高效液相色谱法可以在pH 2～11、离子强度0.02 mol/L到2 mol/L NaCl范围内有效地检测双酚A;溶液中的共存阴离子N03-、S04-或共存有机质葡萄糖、单宁酸、没食子酸对检测并没有明显影响;然而当溶液中存在CO32-和p034-时,本研究采用的高效液相色谱法将无法有效检测双酚A,应用时需注意.     

分散液液微萃取-石墨炉原子吸收光谱法测定环境水样中的痕量镉

建立了分散液液微萃取分离富集一石墨炉原子吸收光谱法测定环境水样中痕量镉的新方法。以二乙基二硫代氨基甲酸钠为螯合剂、四氯化碳为萃取剂、丙酮为分散剂,详细考察YpH值、螯合剂质量分数、萃取剂体积、萃取时间等因素的影响。在优化的实验条件下,方法对水样中镉的检出限为4．2ng-L^-1,线性范围是20-300ng-L^-1,测定结果的相对标准偏差为3．5％,富集倍数达103。将建立的方法应用于三种实际环境水样中镉的检测,加标回收率在92％-108％范围内。本方法具有灵敏、准确、快速、环保的特点,是一种分析水样中痕量镉的较好方法。     

Cytogenetic studies of amniotic fluid taken before the 15th week of pregnancy for earlier prenatal diagnosis: A report of 114 consecutive cases

One hundred and fourteen samples of amniotic fluid taken before 15 weeks of gestation were cultured for cytogenetic studies. The results of culturing these early amniotic fluid (EAF) samples were compared with the results of culturing 114 standard amniotic fluid (SAP) samples taken after 15 weeks of gestation matched for maternal age and received in the laboratory within the same week. Cell culture was successful in all 114 of the EAF samples and in 111 SAP samples. There was no significant difference in the days to harvesting and days to reporting in the two groups. Three samples of SAP failed to grow and two EAF samples produced tetraploid karyotypes, so that in these five cases amniocentesis had to be repeated. These problems were attributed to toxicity of a fungicide used in the culture medium. Pseudomosaicism was noted in two EAF samples and one SAP sample; and maternal cell contamination was noted in one EAF and one SAP sample. Thus, culturing and karyotyping cells harvested from EAF and SAP are similar, indicating that EAF samples from 12–14-week pregnancies could be used for prenatal diagnosis.     

典型电子废物处置场地表层土壤中的德克隆阻燃剂研究

以我国广东省汕头市贵屿镇典型电子废物处置场地为研究区域,对其表层土中的德克隆(DP)阻燃剂的污染水平及分布模式进行了研究.结果表明,DP在全部23个表层土样品中均被检出,浓度范围为0.308~209ng/g,东南部地区的污染水平显著高于西北部地区,各区域的污染水平也存在一定差异.DP浓度最高点(209ng/g)和次高点(46.2ng/g)均位于主要从事电子废物手工拆解及物理破碎的片区.表层土样品中anti-DP质量分数(fanti)的变化范围为0.444~0.754 (平均值:0.652±0.064),同DP工业品中的fanti值(0.65)不存在显著性差异,表明在表层土中不存在明显的异构体选择性降解.不同的电子废物处置方式对各片区表层土中DP的分布模式影响不明显.     

Cadmium and chromium in human lung tissue in relation to smoking and lung cancer

The pulmonary Cd and Cr content was determined from 53 lung cancer patients operated for cancer and from 39 patients who died of non‐malignant diseases. The results were correlated with smoking habits, pulmonary emphysema and occupational history. Both the pulmonary Cd and Cr increased with the amount of smoking. In ex‐smokers the Cr content in lung tissue did not diminish with the time since stopping smoking, but the Cd did follow the half‐life of about 9 years. The pulmonary Cd, compared with smoking habits, behaved similarly in both the lung cancer and control patients, whereas Cr in the lung cancer patients could not be explained solely by smoking, but some of the cancer patients may have been occupationally exposed to Cr. Speciation was not studied.     

Ecotoxicological testing of soil by four bacterial biotests

The objective of this work was threefold. Firstly, this paper intends to introduce four microbial toxicity screening methods (Bacillus subtilis agar diffusion method, Azotobacter agile and Pseudomonas fluorescens dehydrogenase enzyme inhibition tube test, and Photobacterium phosphoreum contact toxicity test) for the investigation of contaminated solid samples such as soil and sediment. Secondly, this work was carried out to prove that both soil characteristics and chemical form of contaminants influence the bioavailability of contaminants and alter the toxicity of soil sample considerably. Thirdly, the sensitivity of the above mentioned four biotests to different contaminants of the soil (heavy metals, organic compounds) was determined and compared. The data evaluation was processed by computer aided statistical methods such as cluster, correlation and principal components analysis by the use of Statgraphics^R.

According to cluster analysis carried out separately for chemical data and biological data, we observed that those samples that have similar chemical composition do not show similar toxicity, which is probably due to different bioavailability of contaminants, the impacts of soil characteristics as well as interaction of contaminants. According to the investigation of sensitivity of the examined four biotests the following conclusion could be drawn: P. phosphoreum and A. agile tests are similar in the sense that they are sensitive to Cu to a large extent and also to PAHs and hydrocarbons (CH) to a lesser extent. B. subtilis test corresponds well with P. fluorescens test method since both tests give good correlation with heavy metals. Neither B. subtilis nor P.fluorescens biotests are sensitive to organic soil contaminants such as PAH and CH.