表面活性剂增敏分光光度法测定微量锡研究

建立了表面活性剂增敏分光光度法测定水样中微量锡的新方法。锡与二甲酚橙形成络合物,在pH9.5时吸光度A最大,加入聚乙二醇辛基苯基醚（TritonX-100）胶束后,络合物的稳定性好,灵敏度大大增加。实验条件下显色络合物的最大吸收峰位于431nm处,线性范围为Sn2.0—20.0μg/mL,回收率为98.9%—104.2%。此方法选择性好、灵敏度高、操作简单,用于分析水样中的微量锡,结果令人满意。     

亚甲蓝分光光度法测定水中阴离子表面活性剂分析方法的探讨与研究

亚甲蓝分光光度法是测定水和废水中阴离子洗涤剂的国家标准方法之一。该方法的优点是灵敏度高,准确度好,但缺点是实验过程中要反复多次萃取,试剂用量大,而且结果容易偏低。本文就亚甲蓝分光光度法测定阴离子表面活性剂过程中遇到的实际问题进行了探讨与研究,就其结果偏低的原因及实验中应注意的事项给予了详尽的阐述和分析。     

二苯偶氮羰酰肼分光光度法测定岩石样品中的铜

本文简单阐述了用二苯偶氮羰酰肼分光光度法测定岩石样品中铜的方法及优点,不仅扩展了二苯偶氮羰酰肼的应用范围,也为岩石中铜的测定提供了新思路。     

紫外可见分光光度法测定铜及铜合金抛光液中的硝酸根

研究了紫外可见分光光度计在301.7nm处测定铜及铜合金抛光液中硝酸根的浓度。方法的线性范围为0.9662—9.6621g/L,适合于该类型抛光液中硝酸根的检测。该方法快速简便、准确度高、精密度好。     

悬浮液进样技术测定茶叶中的微量铜和锌

悬浮液进样─火焰原子吸收光谱法能简便、快速、准确地测定样品中的微量元素,本文采用该方法测定茶叶中的微量铜和锌,对试验条件、悬浮剂的选择进行了优化。结果表明：铜、锌的检出限分别为0.01μg.mL-1和0.027μg.mL-1,加标回收试验铜的回收率为95.3%～104.2%,锌的回收率为100.6%～104.1%。     

分光光度法测定丙烯中的痕量硫

建立了分光光度法测定丙烯中痕量硫的方法,当样品中硫质量分数在0—1mg/kg内,样品中硫含量与吸光度呈良好的线性关系,检出限为0.1mg/kg。该方法适用于丙烯中痕量硫的测定。     

Copper and Zinc Status in Psoriasis: Correlation with Severity

Psoriasis is a common and an inflammatory skin disease. Trace elements play an important role in the skin metabolism such as keratinisation and melanin formation as well as immunological and inflammatory reactions. Henceforth, the present study was aimed to evaluate the essential metals with special reference to Cu and Zn. In this study, 72 psoriatic patients and 50 controls were enrolled. On the basis of PASI score psoriatic group comprising of 48 mild and 24 severe psoriatic patients were grouped. The serum trace elements analysis in the subjects revealed that serum Cu levels and Cu/Zn ratio was significantly higher in the psoriatic patients as compared to controls. Interestingly, severity of the psoriasis was well correlated with the serum Cu levels. Taking together, all these findings suggest that Cu may be a major culprit in the pathogenesis as well as in the severity of the disease.     

Regional Distribution of Copper,Zinc and Iron in Brain of Wistar Rat Model for Non-Wilsonian Brain Copper Toxicosis

In previous studies, we have reported first in vivo evidence of copper deposition in the choroid plexus, cognitive impairments, astrocytes swelling (Alzheimer type II cells) and astrogliosis (increase in number of astrocytes), and degenerated neurons coupled with significant increase in the hippocampus copper and zinc content in copper-intoxicated Wistar rats. Nonetheless, hippocampus iron levels were not affected by chronic copper-intoxication. Notwithstanding information on distribution of copper, zinc and iron status in different regions of brain due to chronic copper exposure remains fragmentary. In continuation with our previous study, the aim of this study was to investigate the effects of intraperitoneally injected copper lactate (0.15 mg Cu/100 g body weight) daily for 90 days on copper, zinc and iron levels in different regions of the brain using atomic absorption spectrophotometry. Copper-intoxicated group showed significantly increased cortex, cerebellum and striatum copper content (76, 46.8 and 80.7 % increase, respectively) compared to control group. However, non-significant changes were observed for the zinc and iron content in cortex, cerebellum and striatum due to chronic copper exposure. In conclusion, the current study demonstrates that chronic copper toxicity causes differential copper buildup in cortex, cerebellum and striatum region of central nervous system of male Wistar rats; signifying the critical requirement to discretely evaluate the effect of copper neurotoxicity in different brain regions, and ensuing neuropathological and cognitive dysfunctions.     

ICP-AES法同时测定栗子中的微量元素

采用湿法消解样品,ICP-AES法同时测定栗子中Ca、Mg、P、K、Fe、Cu、Mn、Zn、As、Si、Cr、Co等12种微量元素的含量。该方法简单、快速、灵敏度高,准确性好。回收率在88.0%～114%之间之间,相对标准偏差小于4.2%。实验结果证明:栗子中含有丰富的对人体有益的K、P、Mg、锰等元素。     

Status and Interrelationship of Zinc,Copper, Iron,Calcium and Selenium in Prostate Cancer

Deficiency or excess of certain trace elements has been considered as risk factor for prostate cancer. This study was aimed to detect differential changes and mutual correlations of selected trace elements in prostate cancer tissue versus benign prostatic hyperplasia tissue. Zinc, copper, iron, calcium and selenium were analysed in histologically proven 15 prostate cancer tissues and 15 benign prostatic hyperplasia tissues using atomic absorption spectrophotometer. Unpaired two tailed t test/Mann–Whitney U test and Pearson correlation coefficient were used to compare the level of trace elements, elemental ratios and their interrelations. As compared to benign prostatic tissue, malignant prostatic tissue had significantly lower selenium (p = 0.038) and zinc (p = 0.043) concentrations, a lower zinc/iron ratio (p = 0.04) and positive correlation of selenium with zinc (r = 0.71, p = 0.02) and iron (r = 0.76, p = 0.009). Considerably divergent interrelationship of elements and elemental ratios in prostate cancer versus benign prostatic hyperplasia was noted. Understanding of differential elemental changes and their interdependence may be useful in defining the complex metabolic alterations in prostate carcinogenesis with potential for development of element based newer diagnostic, preventive and therapeutic strategies. Further studies may be needed to elucidate this complex relationship between trace elements and prostate carcinogenesis.     

人血清中微量铜的化学发光法测定

基于Cu~(2+)对鲁米诺-MnO_4~-化学发光反应的抑制作用建立了血清铜含量的化学发光分析法.测定铜(Ⅰ)的检出限为8.6×10~(-9)/ml,线性范围为1.0×10~(-8)～2.0×10~(-6)g/ml;对含1.0×10~(-7)g/ml cu~(+2)的水溶液进行10次重复测定,其结果的变异系数为4.3％.将本法应用于人血清中铜含量的测定,结果满意。     

β修正──丁基罗丹明B－OP新光度法测定工业废水中砷含量

在酸性溶液中，砷（Ａｓ￣（５＋））与丁基罗丹明Ｂ（ＢＲＢ）反应，显色液由红色变紫色，非离子表面活性剂ＯＰ能提高分析灵敏度并增大ＢＲＢ及其与砷络合产物溶解性。本文研究β修正光度法测定工业废水中痕量砷，它能消除过量ＢＲＢ的干扰提高分析灵敏度、精密度和准确度。结果表明砷浓度０～０．４０ｍｇ／Ｌ时，修正吸光度有良好线性关系，检出限０．００４ｍｇ／Ｌ，加标回收率９３．０％～１１１％，相对标准偏差ＲＳＤ≤６．５％。该方法适合于化工废水、城市污水及各种环境水质分析。     

中国科学院“应对气候变化国际谈判的关键科学问题”项目群简介

以人为温室气体排放为核心的气候变化问题已成为国际社会、科技界和社会公众关注的焦点之一,且已深入到国际政治和外交层面。我国在深度参与国际控制CO2浓度的谈判之前,亟待组织全面系统的科学研究,解决应对气候变化及国际谈判面临的关键科学问题。中科院设立了“应对气候变化国际谈判的关键科学问题”项目群,针对气候变化的原因和机制、影响与适应、生态系统固碳潜力与途径、应对气候变化国际谈判的政策等开展研究,以期在气候变化理论研究上取得突破,并为我国参与国际谈判提供科学保障。