超临界流体萃取法

介绍了超临界流体的性质：超临界流体萃取法的原理，特点及应用。讨论了应用超临界流体萃取进行样品预处理的条件选择：超临界流体的选择，列举了数种常用的超临界流体，详尽介绍了ＣＯ２的特性及其在样品预处理中的应用范围；萃取条件选择的预测方法，试验方法，萃取压力的选择，， 同类别物质的以，不联机及联机的收集技术等。     

废弃电子塑料在超临界异丙醇中的液化特性

研究了废弃含溴化阻燃剂的电子塑料在超临界异丙醇中的液化特性.研究结果表明塑料在超临界异丙醇中发生了解聚,产生油、气以及固体残渣,塑料中的溴化阻燃剂发生了脱溴降解.反应时间、固/液比、溶剂填充度对塑料解聚及阻燃剂脱溴降解影响较大,在最佳工艺条件(温度:400℃,反应时间:60min,固/液比:1/10,溶剂填充度:50%)下获得60%的产油率及95.3%的脱溴率.油以苯系物及酚类物质为主要组成物质,其热值为37.5MJ/kg.超临界异丙醇处理含溴化阻燃剂塑料主要包括溴化阻燃剂的萃取、脱溴降解和塑料高温解聚等过程.     

环境样品有机物分析预处理技术研究进展

在环境污染治理过程中,对环境样品进行预处理以进行分析检测必不可少,尤其针对环境中痕量存在的污染物,需经过预处理,浓缩被测痕量组分,以便提高检测方法的灵敏度,降低最小检测极限,并且可以使样品变得容易保存和运输。文章详细介绍了环境样品中有机物分析的预处理方法,将方法分为传统预处理方法和较新预处理方法,传统预处理方法包括:索氏提取法、超声波提取法、真空升华法、气相色谱法、液相色谱法;较新预处理方法包括:超临界流体萃取技术、固相微量萃取技术和吹扫捕集法。分别就传统和较新预处理方法的原理、优缺点及适用范围进行归纳总结和对比,并以多环芳烃的提取为例列举了各方法的应用步骤,从而为其他环境样品其他有机物分析预处理提供参考。     

中─高级变质相中水热流体的形成与作用

固体地壳中流体是普遍存在的，中—高级变质相中的矿物并非只发生晶体塑性变形，溶解和溶移作用在非糜棱岩化岩石中占主导地位，因为高温高压环境下存在的水热流体，在变质变形作用中起着至关重要的作用。在周围分布有网络状进进剪切带的递进缩短带中，与应交梯度有直接关系的单个矿物的位错密度梯度在其晶体边缘形成，产生了化学位梯度，从而使矿物边缘发生溶解。变形分解作用是产生这一过程的动力，并为流体汇聚形成水热循环系统提供了空间。     

旋流分离器油水分离效率的模拟研究

采用计算流体力学的方法,探讨了操作条件和物料特性对旋流分离器分离油水效率的影响。旋流器为单锥双入口,其主直径为50 mm,锥角为5.5°。模拟过程中,采用商业用软件‘Fluent 6.3’中的雷诺应力模型和欧拉多相流模型来模拟不同条件下油水旋流分离器的分离性能。模拟结果表明,对于本研究的油水旋流分离器,最佳的分流比是10%,最佳的油滴浓度是0.5%(V/V)。在最佳的分流比和油滴浓度下,当进口流速为10.46 m/s时,油水旋流分离器可将15μm的油滴去除80%以上,油滴的分离界限粒径d50(50%的分离效率)为9.2μm。在模拟的基础上,用统计软件STATISTICA6.0对分离效率与操作条件和物料特性之间的关系进行拟合。通过拟合式预测的分离效率与实测值相吻合,误差小于15%。     

国产防锈水及其组成成分对鼠伤寒沙门氏菌诱发突变作用的研究

国产防锈水对鼠伤寒沙门氏菌直接试验和加肝微粒体酶试验均能引起TA100菌株突变,并且有剂量-效应关系。对于各主要成分的分别检查表明,工业品亚硝酸钠可能含有的杂质或在贮藏过程中形成的物质对沙门氏菌有直接致突变作用。进一步研究发现,分析纯亚硝酸钠本身Ames直接试验阴性,但使用分析纯的亚硝酸钠与聚乙二醇、三乙醇胺配成的防锈水Ames直接、间接试验均为阳性,这提示亚硝酸钠与三乙醇胺等在一起产生了新的直接或间接的致突变物质,防锈水配方中亚硝酸钠、三乙醇胺的存在可能在体内、体外合成N-亚硝基化合物。     

Application of Neomysis awatschensis as a standard marine toxicity test organism in China

The small mysid crustacean Neomysis awatschensis was collected in the west coast of Jiaozhou Bay, Qingdao, China in 1992 and acclimated and cultured in laboratory conditions since then. Standard acute toxicity tests using 4--6 d juvenile mysids of this species were conducted and the results were compared with Mysidopsis bahia, a standard toxicity test organism used in the US in terms of their sensitivities to reference toxins, as well as their taxonomy, morphology and geographic distributions. Because of its wide distribution along the Chinese coast, similar sensitivity to pollutants as M. bahia, short life history, small size and the ease of handling, this study intended to use N-awatschensis as one of the standard marine organisms for toxicity testing in China. The species were applied to acute toxicity evaluations of drilling fluid and its additives, organotin TPT and toxic algae, and to chronic (life cycle) toxicity assays of organotin TPT and a toxic dinofalgellate Alexandrium tamarense, respectively. Using N. awatschensis as a standard toxicity testing organism in marine pollution assment in China is suegested.     

First-trimester amniotic fluid and extraembryonic coelomic fluid acetylcholinesterase electrophoresis

Acetylcholinesterase (AChE) gel electrophoresis was performed on samples of amniotic fluid and extraembryonic coelomic fluid obtained by high resolution transvaginal ultrasound-guided amniocentesis from 38 women between 8 and 12 weeks of pregnancy. AChE was positive in 33 per cent (12/36) of the amniotic fluid samples; the percentage of positive results decreased as gestation advanced. AChE was positive in 32 per cent (9/28) of the extraembryonic coelomic fluid samples. In 81 per cent (21/26) of matched samples, the AChE results were identical in the two fluids. Amniotic fluid and extraembryonic coelomic fluid AChE electrophoresis cannot be used to diagnose neural tube defects prior to 12 weeks of gestation.     

Non-ketotic hyperglycinaemia: Glycine/serine ratio in amniotic fluid–an unreliable method for prenatal diagnosis

We describe a prenatal diagnosis of a fetus at risk for non-ketotic hyperglycinaemia based on the glycine/serine ratio in amniotic fluid at 16 weeks of gestation. Although the glycine level and the glycine/serine ratio in amniotic fluid were within the normal range, the fetus was affected and therefore a false-negative prediction was made. The reliability of this method is questioned.     

Prenatal tests for Sanfilippo disease type B in four pregnancies

We report the prenatal diagnosis of two fetuses with Sanfilippo disease type B. In both pregnancies there were excessive amounts of heparan sulphate in amniotic fluid and the activity of N-acetyl-α-D-glucosaminidase was undetectable in cultured amniotic fluid cells. The predictions were confirmed by enzyme assay of cultured skin fibroblasts from the aborted fetus or the affected infant. The disorder was excluded for two other pregnancies at risk and the predictions are considered to be correct because of the normal progress of the healthy children.