共查询到20条相似文献,搜索用时 46 毫秒
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《塑料工业》2017,(7)
利用高效液相-三重四级杆串联质谱测定了丙烯腈-苯乙烯食品塑料包装材料中邻苯二甲酸酯(PAEs)的含量。结果显示,该包装材料中均检测到邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二辛酯(DNOP)、邻苯二甲酸二异壬酯(DINP)、邻苯二甲酸二(2-乙基己烷)酯(DEHP)和邻苯二甲酸苯甲基丁酯(BBP),其中DEHP的含量最高。考察浸泡溶剂、浸泡时间和浸泡温度对PAEs迁移量的影响,结果显示,脂溶性溶剂和高温条件有助于食品包装材料中PAEs的释放,而在室温条件下,PAEs的释放量有限。由于目前大多数食品通常在室温甚至低温下贮藏,因此,日常食品包装材料中PAEs对食品的污染程度很低,没必要恐慌。 相似文献
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对2011—2016年贵州省市售多类化妆品中汞含量进行检测分析,以了解全省市售化妆品中汞的分布情况,并分析其安全风险。实验采用微波消解法对样品进行预处理,氢化物原子荧光光度法对样品中的汞含量进行测定。结果表明,832批次样品中512批次检出汞,检出率61.5%;40批次样品汞含量超过国家标准,超标率4.8%;研究出现汞超标的样品中,国产宣称美白或祛斑类产品超标率最高,为11.5%,该类超标产品中83.3%超过国家标准1 000倍。 相似文献
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阐述国际上对PVC医疗器械释放DEHP[邻苯二甲酸二(2-乙基)己酯]安全性评价的思路以及我国对医疗器械释放DEHP的限量要求。选取市面上输血器作为样品,采用模拟浸提和极限浸提的方式进行浸提,分析浸提液中DEHP的含量,对样品释放DEHP的安全性进行评价。 相似文献
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为掌握佛山市顺德新城区降水中污染物的情况,2015年7月至8月,文章作者分别在雨天进行了降水取样,对降水中的pH、电导率、常见阴离子(F-、Cl~-、NO_3~(2-)、SO_4~(2-))及部分重金属(铅和镉)进行监测分析。选择有相关数据的珠江三角洲和石家庄、厦门等地的降水中污染物的情况进行对比。结果表明,顺德新城区降水中的p H和部分阴离子浓度优于珠江三角洲平均值,酸雨类型属于硫酸和硝酸混合型;其水体洁净程度略差于石家庄;铅和镉的浓度也高于厦门,甚至部分超出了人体能直接接触的安全范围。 相似文献
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Saturated very long chain fatty acids (fatty acids with greater than 22 carbon atoms; VLCFA) accumulate in peroxisomal disorders,
but there is little information on their turnover in patients. To determine the suitability of using stable isotope-labeled
VLCFA in patients with these disorders, the metabolism of 22-methyl[23,23,23-2H3]tricosanoic (iso-lignoceric) acid was studied in rats in vivo and in human skin fibroblasts in culture. The deuterated iso-VLCFA was degraded to the corresponding 16- and 18-carbon iso-fatty acids by rats in vivo and by normal human skin fibroblasts in culture, but there was little or no degradation in peroxisome-deficient (Zellweger’s
syndrome) fibroblasts, indicating that its oxidation was peroxisomal. Neither the 14-, 20-, and 22-carbon iso-fatty acids nor the corresponding odd-chain metabolites could be detected. In the rat, the organ containing most of the iso-lignoceric acid, and its breakdown products, was the liver, whereas negligible amounts were detected in the brain, suggesting
that little of the fatty acid crossed the blood-brain barrier. Our data indicate that VLCFA labeled with deuterium at the
ω-position of the carbon chain are suitable derivatives for the in vivo investigation of patients with defects in peroxisomal β-oxidation because they are metabolized by the same pathways as the
corresponding n-VLCFA. Moreover, as iso-VLCFA and their β-oxidation products are readily separated from the corresponding n-fatty acids by normal chromatographic procedures, the turnover of VLCFA can be more precisely measured.
A preliminary report of part of this work (Reference 18) was presented at the 5th International Symposium on the Synthesis
and Applications of Isotopes and Isotopically Labelled Compounds, Strasbourg, France, June 20–24, 1994. 相似文献
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高效液相色谱法分析化妆品中微量成分的研究进展 总被引:1,自引:0,他引:1
综述了高效液相色谱法在化妆品中防腐剂、防晒剂中紫外线吸收剂以及性激素的检测等几个方面的应用;同时,介绍了分析所用的色谱柱、流动相、使用的检测手段以及样品的提取方法;最后针对目前存在的问题,提出了高效液相色谱用于化妆品中微量成分分析的研究方向和发展前景。 相似文献
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H. Toda Y. Mochizuki T. Kawanishi H. Kawashima 《Nutrient Cycling in Agroecosystems》2002,63(2-3):167-173
In a coastal agricultural area in the central part of Japan (Shizuoka), we found decreasing nitrate concentration with depth in a shallow groundwater, where the depth to water table varied between 0.6 and 1.2 m below ground surface. High nitrate concentrations (5–29 mg N L–1) were often observed in the upper layer (0–2 m) of the groundwater, but the concentration decreased to less than 1 mg N L–1 in the deeper layer. Ammonium was scarcely detected, and the concentration of dissolved oxygen was usually low (< 1 mgO2 L–1) in the groundwater. Nitrate in the groundwater often had very heavy nitrogen stable isotope ratios (>20{}). There was a negative relationship between nitrogen stable isotope ratio of nitrate and its concentration. When nitrate was injected into the groundwater with acetylene and bromide (a conservative tracer), nitrate concentration decreased to 20% of the initial level within 5 days, accompanied by the increase in nitrite and nitrous oxide concentration and a little change in bromide concentration. These results indicate that microbial denitrification plays a potential role in the decrease of nitrate in shallow groundwater at the study site. 相似文献
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我国硝酸工业生产技术新进展 总被引:1,自引:0,他引:1
系统叙述了我国硝酸工业2000-2007年生产现状及主要技术成果,尤其指出了国产"四合一"机组的成功投运,使我国硝酸国产化装置取得较大的进步,表现在吨酸的铂耗、氨耗和能耗等方面接近国外引进装置水平,同时介绍了国外双加压法硝酸生产技术的进展.我国已成为硝酸生产大国,仍需以先进的技术改造和发展我国硝酸工业,确保我国硝酸工业健康有序地发展,加快从硝酸生产大国向强国迈进的步伐. 相似文献