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《化学试剂》2021,43(11):1551-1555
建立了罐采样-预浓缩-气相色谱质谱联用仪测定环境空气中10种消耗臭氧层物质(ODS)的分析方法。采用硅烷化的苏玛罐采集环境空气,三级冷阱预浓缩富集,色谱柱为Gas-Pro色谱柱(60 m×0.32 mm),采用全扫描模式(SCAN)和选择离子模式(SIM)同时进行测定,内标法定量,优化了色谱柱、初始柱温条件。结果表明:当取样量为400 mL时,10种ODS在35.0 pmol/mol~4.0 nmol/mol范围内具有良好的线性关系,且平均相对响应因子的相对标准偏差为2.5%~14.0%,检出限为9.6~31.6 pmol/mol,平均加标回收率为71.5%~112.8%,相对标准偏差为0.4%~10.9%。方法操作简单、检出限低、可满足环境空气中ODS pmol/mol~nmol/mol浓度量级的要求,精密度好、准确度高,适用于环境空气中10种ODS的测定。 相似文献
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建立汽车制造企业工作场所空气中9种挥发性有机物的气相色谱快速测定方法,用活性炭采集工作场所空气中挥发性有机物,经二硫化碳解吸后用毛细管气相色谱法测定.结果9种挥发性有机物在一定浓度范围内线性关系良好,相关系数r >0.999 5,相对标准偏差为0.2%~0.8%,最低检出限为0.1 ~0.3 mg/m3,平均解吸效率为91.3% ~104.1%.该方法准确度高,操作简便,灵敏快速,适用于汽车制造企业工作场所空气中挥发性有机物的快速测定. 相似文献
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使用惰性化采样瓶进行污染源废气的采集,利用带有定量环的大气预浓缩系统和气质双检测器联用技术,建立测定固定污染源废气中97种挥发性有机物(VOCs)的分析方法。结果显示,97种VOCs在校准曲线范围内线性良好,相关系数(r2)为0.993~1.000,方法检出限为3.34~23.03 nmol/mol,定量下限为13.36~92.12 nmol/mol;VOCs的回收率为93.3%~114%,相对标准偏差(RSD,n=6)为0.10%~14.0%;VOCs采样瓶中存储7天回收率在100%±20%范围内。运用该方法对不同类型企业废气中VOCs进行测定,VOCs均有不同程度的检出,TVOC浓度范围为9.32~46.3 mg·m3。 相似文献
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建立汽车制造企业工作场所空气中9种挥发性有机物的气相色谱快速测定方法,用活性炭采集工作场所空气中挥发性有机物,经二硫化碳解吸后用毛细管气相色谱法测定。结果 9种挥发性有机物在一定浓度范围内线性关系良好,相关系数r>0.999 5,相对标准偏差为0.2%~0.8%,最低检出限为0.1~0.3 mg/m3,平均解吸效率为91.3%~104.1%。该方法准确度高,操作简便,灵敏快速,适用于汽车制造企业工作场所空气中挥发性有机物的快速测定。 相似文献
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采用索氏提取法、加压流体萃取法、干样法三种前处理方法分别对土壤半挥发性有机物进行测定和验证,得出索氏提取法的检出限分布在0.004~0.13 mg/kg,相对标准偏差分布在0.8%~11.1%,加标回收率分布在74%~108%;加压流体萃取法的检出限分布在0.002~0.07 mg/kg,相对标准偏差分布在0.4%~11.2%,加标回收率分布在74%~110%;干样法的检出限分布在0.004~0.11 mg/kg,相对标准偏差分布在0.2%~11.4%,加标回收率分布在74%~111%,均具备较高的精密度和回收率。三种方法均可适用于测定土壤半挥发性有机物。 相似文献
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建立了塑胶跑道中35种挥发性有机化合物(VOCs)的热解析-气相色谱-质谱法的检测方法。样品预平衡后,经环境舱释放并采集气体,用热解析-气相色谱-质谱法测定,标准曲线定量。35种挥发性有机化合物(VOCs)在0.01~1.0 mg/m~3浓度范围内线性良好,相关系数0.99。当采样体积为5 L时,检出限为0.000 01~0.000 4 mg/m~3。在0.02、0.1和0.6 mg/m~3 3个浓度下,相对标准偏差(n=6)为1.6%~9.7%。方法可用于塑胶跑道中挥发性有机化合物(VOCs)的定性和定量检测,为研究其对人体可能产生的危害提供重要依据。 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