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排序方式: 共有111条查询结果,搜索用时 31 毫秒
61.
62.
建立了防火涂料中阻燃剂六溴环十二烷(HBCD)的气相色谱-质谱(GC-MS)分析方法。样品用二氯甲烷进行萃取,萃取液经有机滤膜过滤后,用气相色谱-质谱联用仪进行测定。在选择离子检测模式下以m/z 157、239、319、401为定性离子,m/z 239为定量离子进行结构确证和定量检测。在优化的实验条件下,六溴环十二烷标准溶液在5~100 mg/L的质量浓度范围内线性关系良好,相关系数大于0.999。对市售的空白丙烯酸树脂涂料样品及环氧树脂涂料样品进行加标回收试验,结果表明本方法的平均回收率为92.9%~116.3%, RSD不超过8%。方法的检出限(S/N=3)为30 μg/g,定量限(S/N=10)为100 μg/g。本方法简便、快速、准确性好、精密度高,能够满足检测工作的实际要求。 相似文献
63.
《Journal of separation science》2017,40(19):3873-3881
Due to new European legislation, products going to waste are subject to ‘low persistent organic pollutant concentration limits’. Concentrations of restricted brominated flame retardants in waste products must be determined. A rapid extraction and clean‐up method was developed for determination of brominated flame retardants in various plastics and textiles. The optimised method used vortexing and ultrasonication in dichloromethane followed by sulfuric acid clean‐up to determine target compounds. Poly‐brominated diphenyl ethers were determined by gas chromatography with mass spectrometry and hexabromocyclododecane by liquid chromatography with tandem mass spectrometry. Good recoveries of target analytes were obtained after three extraction cycles. The method was validated using poly‐propylene and poly‐ethylene certified reference materials as well as previously characterised textiles, expanded and extruded poly‐styrene samples. Measured concentrations of target compounds showed good agreement with the certified values indicating good accuracy and precision. Clean extracts provided low noise levels resulting in low limits of quantification (0.8–1.5 ng/g for poly‐brominated diphenyl ethers and 0.3 ng/g for α‐, β‐ and γ‐hexabromocyclododecane). The developed method was applied successfully to real consumer products entering the waste stream and it provided various advantages over traditional methods, including reduced analysis time, solvent consumption, minimal sample contamination and high sample throughput, which is crucial to comply with the implemented legislation. 相似文献
64.
Francesca Buiarelli Patrizia Di Filippo Donatella Pomata Carmela Riccardi Martina Bartocci 《International journal of environmental analytical chemistry》2017,97(9):797-818
A novel multi-analyte method for the simultaneous determination of 46 compounds of environmental concern, most of them belonging to the category of persistent organic pollutants, was developed using high-performance liquid chromatography and the results were compared to those obtained by gas chromatography. This study was performed in perspective of a cumulative exposure assessment of substances of health concern in environments where high levels, relatively to airborne particulate matter, can be found. The target compounds included polychlorinated biphenyls, brominated flame–retardants and derivatives of polycyclic aromatic hydrocarbons.The multi-analyte method was evaluated in air particulate matter in terms of reproducibility, linearity, recovery, limits of detection and quantification and matrix effect. The recovery was above 70% for all the analytes, whereas limits of quantification ranged between 23 and 390 pg?m?3 in liquid chromatography and less than ten times in gas chromatography–mass spectrometry.Matrix effect was generally negligible for both the techniques, except the case of the detection of oxygenated derivatives of polycyclic aromatic hydrocarbons by gas chromatography.In order to demonstrate the efficacy and to assess the method performances (accuracy and precision), both the techniques were applied to standard reference materials, and the results were compared, discussing their advantages and disadvantages.The method was finally applied to a real sample of indoor airborne particulate matter with aerodynamic diameter ≤4 μm (PM4).We demonstrated that liquid chromatography was the only technique able to analyse the 46 compounds, including thermally degradable ones, with a single chromatographic run without derivatisation steps. On the other hand, gas chromatography still presents higher sensitivity for the detection of some of the investigated compounds. This study can be considered only explorative and further improvements can be expected with new-generation LC-MS instruments (10–100 times more sensitive). 相似文献
65.
食品中多溴联苯醚残留的气相色谱-串联质谱分析方法研究 总被引:1,自引:0,他引:1
建立了食品中8种多溴联苯醚(PBDEs) 残留的气相色谱-串联质谱分析方法,初步解析了PBDEs的电子轰击串联质谱(EI MS/MS)图,为各种目标物的准确定性分析提供依据.以BDE-28、BDE-47、BDE-66、BDE-85、BDE-99、BDE-100、BDE-153、BDE-154为研究对象,对EI MS/MS各分析参数进行了优化.用超声提取-酸性硅胶层析柱净化的前处理方法制备样品,当空白样品的加标水平为10.0、25.0 μg/kg时,8种PBDEs的平均加标回收率为82% ~112%,相对标准偏差为3.1% ~15%,方法检出限均低于1.5 μg/kg;8种PBDEs的线性范围为10.0 ~500 μg/kg,相关系数均大于0.994 7. 相似文献
66.
In recent years the number of environmental applications of elemental speciation analysis using inductively coupled plasma mass spectrometry (ICP-MS) as detector has increased significantly. The analytical characteristics, such as extremely low detection limits (LOD) for almost all elements, the wide linear range, the possibility for multi-elemental analysis and the possibility to apply isotope dilution mass spectrometry (IDMS) make ICP-MS an attractive tool for elemental speciation analysis. Two methodological approaches, i.e. the combination of ICP-MS with high performance liquid chromatography (HPLC) and gas chromatography (GC), dominate the field. Besides the investigation of metals and metalloids and their species (e.g. Sn, Hg, As), representing “classic” elements in environmental science, more recently other elements (e.g. P, S, Br, I) amenable to ICP-MS determination were addressed. In addition, the introduction of isotope dilution analysis and the development of isotopically labeled species-specific standards have contributed to the success of ICP-MS in the field. The aim of this review is to summarize these developments and to highlight recent trends in the environmental application of ICP-MS coupled to GC and HPLC. 相似文献
67.
68.
Prashant A. Bhadane John Cheng Maria D. Ellul Basil D. Favis 《Journal of Polymer Science.Polymer Physics》2012,50(23):1619-1629
In this study, a dynamic vulcanized alloy of brominated poly(isobutylene‐co‐p‐methylstyrene) (BIMSM) and polyamide (PA) has been investigated. An interfacial reaction between BIMSM and PA and a crosslinking reaction between BIMSM molecules is carried out simultaneously during melt blending. To form a vulcanized, nanoscale elastomer dispersion, the timing of these reactions is key and the interfacial reaction should be well advanced before the vulcanization reaction initiates. At a blending temperature of 205 °C, independent of the processing conditions, it is found that the interfacial reaction dominates the phase morphology development. Increasing the melt processing temperature, however, begins to favor the vulcanization reaction over the interfacial reaction. In nonplasticized blends, it is found that increasing the temperature above 235 °C increases the speed of the vulcanization reaction to a level that it dominates the phase morphology development. As a result, the phase size increases by 2.5‐fold because the system is vulcanized before the interfacial modification step is complete. Adding plasticizer to the PA matrix increases the overall phase size, but shows a similar behavior with increase in temperature from 205 to 255 °C. The critical temperature where the vulcanization reaction starts dominating phase morphology in the plasticized systems is at 225 °C. Once the processing temperature is above the critical temperature, it is found that the mixing sequence can be used to time and decouple the reactions. The work demonstrates that a close control over the temperature and processing conditions can be used to decouple the interfacial and vulcanization reactions resulting in vulcanized, nanoscale dispersions for the BIMSM and PA system. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 相似文献
69.
Two new sesquiterpenoid derivatives, attributable to eudesmane-type (1–2, named septemlobin D and 11,12-O-isopropylidenesolajiangxin F), were isolated from the whole plant of Solanum septemlobum. Their structures were elucidated on the basis of integrated spectroscopic techniques, mainly HR-FAB-MS, 1D and 2D-NMR (1H–1H COSY, HMQC, HMBC and ROESY). In vitro, two sesquiterpenoid derivatives were found to show significant cytotoxicity against three cancer cell lines (P-388, HONE-1 and HT-29), and gave IC50 values in the range of 3.0–7.3 μM. 相似文献
70.
Dong Liu Jing Xu Wei Jiang Zhiwei Deng Nicole J. de Voogd Peter Proksch Wenhan Lin 《Helvetica chimica acta》2011,94(9):1600-1607
Chemical examination of the Chinese marine sponge Xestospongia testudinaria resulted in the isolation and characterization of twelve new brominated acetylenic acids, namely xestospongienols A–L ( 1a – 1d, 2a – 2d , and 3a – 3d ), together with the known analog 4 . The structures of xestospongienols A–L were determined on the basis of 1D‐ and 2D‐NMR, IR, and MS analysis in association with the modified Mosher method. The structural patterns are characteristic of brominated unbranched C16‐alkyl chains containing polyene and acetylene moieties. 相似文献