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对不同的样品处理及测定范围下总氮测定值的变化进行对比,筛选出改进方法,并对改进后进行测定的结果进行了分析。在0.1~0.5工作范围下,标准工作液浓度与吸光度之间的相关系数r=0.99995,呈极显著相关;方法平均回收率99.6%,回收较好;使用共同试验样及国家基准样进行比对分析,测定结果与参考值不存在明显差异,即不存在系统误差。 相似文献
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采用冷原子吸收法,使用便携式测汞仪对实验室空气中汞的浓度进行测定,监测结果表明,环境监测实验室空气中汞的污染较为严重,主要来源于COD、氨氮、大气中氨及汞样品测定时含汞试剂及汞标液的使用和含汞废液的排放。根据对监测结果的评价和分析提出了相应的防治措施,提醒实验室的管理及分析人员,要增强环境保护意识,加强实验室的管理,减少含汞及其它有毒废液的排放,改善实验室的环境空气质量,保护分析人员的身体健康。 相似文献
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提高工业废水中矿物油测定结果准确度的方法探讨 总被引:3,自引:0,他引:3
工业废水中矿物油监测分析存在着水样代表性、稀释误差和标准油品差异等多种因素 ,影响测定结果的准确度。本文就紫外法测定工业废水中矿物油含量的影响因素进行了分析探讨 ,提出提高该项目测定结果准确度的方法。 相似文献
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环境内分泌干扰物前处理方法研究新进展 总被引:1,自引:0,他引:1
环境内分泌干扰物因其能够紊乱生物体正常内分泌功能而引起人们的广泛关注,然而内分泌干扰物在水环境中浓度极低,水体中复杂机质的干扰较大,在分析监测前一般要经过样品前处理过程,以起到富集痕量组分、消除基体干扰、提高方法灵敏度的作用。针对不同环境样品中内分泌干扰物的前处理方法不同,分别介绍了液体、固体或类固体环境样品的前处理技术,提出了各前处理方法的优缺点,总结并展望了环境内分泌干扰物样品前处理方法的发展方向。 相似文献
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对国内的饮用水水源地内分泌干扰物污染现状进行总结,发现我国饮用水水源地很多地区都存在着内分泌干扰物的污染,由于地域的不同,污染物的种类存在差异,但有机氯农药和多氯联苯类化合物的污染尤为严重。同时对水源地内分泌干扰物的种类、来源及生物学效应进行综述,并对内分泌干扰物的毒性作用机制进行了归纳,发现不同来源的内分泌干扰物,毒性作用机制不同,且一种内分泌干扰物可能同时存在多种作用机制。 相似文献
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环境内分泌干扰物的筛选与测试方法的研究是近年来环境科学领域的热点问题.在水生态毒理学研究中,目前的研究重点之一是发展方法学,如基于鱼类实验动物的离体或活体测试方法.对内分泌干扰物鱼类筛选测试的科学基础、内分泌干扰物的生物性标志、筛选测试方法以及用于内分泌干扰物筛选测试的几种主要鱼类实验动物进行了介绍,同时提出了建立适合我国实际情况的内分泌干扰筛选测试鱼类实验动物,并提出系统的鱼类实验动物培育和筛选测试方法体系的必要性. 相似文献
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P. Karlson 《Die Naturwissenschaften》1982,69(1):3-14
Historically, the meaning of the term hormone has changed during the last decades. Morphological studies of secreting cells lead Feyrter to the concept of paracrine action of some hormones. While endocrine regulators are blood-borne, paracrine messengers reach their target cells through the diffusion in the intracellular space. Though it is rather difficult to draw a line between true hormones and hormone-like substances, valid definitions for endocrine and paracrine regulatory systems can be given. The term "hormonal control' should be restricted to endocrine systems. For effectors acting by paracrine mechanisms, the term paramone is proposed in this article. 相似文献
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The potential endocrine disrupting effects and other toxicity effects on aquatic biota resulted from food uptake was simulated by feeding the laboratory cultured rare minnow ( Gobiocypns rams) with field collected Limnodnlus sp. The results indicated that the food chain processes affected significantly the growth, slightly reduced gonadosomatic indices, and elevated hepatosomatic indices. There was an obvious vitellogenin(VTG) induction, which generally only occurred in mature female, in the serum of juvenile rare minnow and mature male when fed with Limnodrilus sp. In addition, the rare minnow feeding on Limnodnlus sp. had significantly high renal indices, it meant obvious renal hyperplasia. The present work suggested that Limnodnlus sp. from field water may contain toxic pollutants and could lead to endocrine disruption effects to the predators. It was concluded that endocrine disruptors may not only be assimilated through water, but also be bioconcentrated through food web. The results also suggested the importance of food selection in conducting the study of endocrine disruption effects using sensitive species. 相似文献
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