共查询到20条相似文献,搜索用时 109 毫秒
1.
同位素稀释高分辨气相色谱-高分辨质谱法测定土壤样品中二恶英类化合物的等价毒性当量不确定度的评定 总被引:2,自引:0,他引:2
采用同位素稀释高分辨气相色谱-高分辨质谱法(isotope dilution high resolution gas chromatography and high resolution mass spectrometry,ID-HRGC-HRMS)测定土壤样品中二恶英类化合物(polychlorinated dibenzo-p-dioxins and dibenzofurans,PCDD/Fs)的等价毒性当量(toxic equivalent quantity,TEQ)。讨论并确定了测定土壤样品中二恶英类化合物2,3,7,8位异构体不确定度的来源并合成了各异构体的相对标准不确定度;在此基础上,计算了3种等价毒性当量因子(toxic equivalent factor,TEF)框架下土壤样品中PCDD/Fs的TEQ浓度及其合成不确定度和扩展不确定度。 相似文献
2.
3.
随机选择空白的和经过印刷的新闻纸和复印纸,粉碎后用溶剂提取并经多步色谱柱纯化,采用同位素稀释、高分辨气相色谱/高分辨质谱(HRGC/HRMS)联用技术分析了其中的二(口恶)(口英)含量.结果表明:新闻纸中二(口恶)(口英)的总量高于复印纸,但是毒性当量却低于复印纸;经过印刷的新闻纸和复印纸中二(口恶)(口英)的含量均高于空白的新闻纸和复印纸;新闻纸和复印纸中相同二(口恶)(口英)异构体的含量是不同的.空白的和经过印刷的新闻纸中二(口恶)(口英)毒性当量分别为0.48 ng/kg和0.61 ng/kg,而空白的和经过印刷的复印纸中二(口恶)(口英)毒性当量分别为0.74 ng/kg和0.79 ng/kg.所有样品中添加的13C标记的2,3,7,8位取代的二(口恶)(口英)回收率均在49.82%至131.34%之间. 相似文献
4.
5.
6.
7.
8.
9.
交互移动窗口因子分析法(AMWFA)用于二维数据重叠色谱峰的比较分析 总被引:9,自引:0,他引:9
采用交互移动窗口因子分析法(AMWFA), 通过挖掘两个体系中的选择性信息, 获得了不同样本间的共有组分数, 还同时得到了各物质对应的光谱或质谱信息. 详细阐述了本法的原理和计算方法, 并用一个模拟的GC-MS 数据对方法进行了验证. 相似文献
10.
采用在线热裂解-气相色谱-质谱联用技术(Py-GC-MS)分析了潜香吡嗪类化合物N-(2,3-吡嗪二甲酰基)-丙氨酸甲酯的热裂解行为。首先通过对2,3-吡嗪二羧酸酰胺化反应合成了新型目标化合物N-(2,3-吡嗪二甲酰基)-丙氨酸甲酯,其结构经X射线单晶衍射(XRD),1H NMR,13C NMR,IR和HR-MS证实,然后在空气氛围中,对目标化合物分别在300,600,900℃下进行热裂解,并通过GC-MS对其挥发性热裂解产物进行定性和半定量分析。结果表明:1裂解形成了包括具有香味特征的吡嗪类、大茴香醇和大茴香醛在内的裂解产物共48种。不同温度下挥发性热裂解产物的类型和相对含量不同,300℃和600℃时相对含量最高的均为乙酸,而900℃时相对含量最高的为吡嗪,且与300℃和600℃裂解条件相比所形成的吡嗪类衍生物种类较多,相对含量较高。2在具有香味特征的裂解产物中,大茴香醇的相对含量随温度升高而升高,而大茴香醛和苯甲醛的相对含量则呈现随着温度升高而降低的趋势。基于目标化合物的热裂解产物的定性及定量变化情况,初步探讨了该物质可能的裂解机理。 相似文献
11.
溴代二噁英(PBDD/Fs)属于潜在的持久性有机污染物,是一种平面三环芳香化合物,具有致畸、致癌、致突变等特性。目前,国际上对PBDD/Fs分析检测的研究是一大热点,但国内对PBDD/Fs的研究却较少。因此,探究PBDD/Fs的分析检测方法,对进一步控制PBDD/Fs污染具有重要科学意义。本文介绍了PBDD/Fs的特性及其分析方法,着重探讨了PBDD/Fs的提取、净化、仪器分析以及质量控制这四个方面,通过对PBDD/Fs的研究能够更好地了解我国当前对PBDD/Fs的分析检测能力,为后续开展PBDD/Fs的分析检测提供科学有效的方法参考。 相似文献
12.
提出了同位素稀释-气相色谱-质谱法测定白酒中23种邻苯二甲酸酯类化合物含量的方法。样品用正己烷-乙酸乙酯(1+1)混合液提取后,经DB-5MS毛细管色谱柱分离,采用电子轰击离子源选择离子反应监测模式进行质谱测定,同位素内标法进行定量分析。23种邻苯二甲酸酯类化合物的线性范围在0.2~3.0mg·L-1之间,测定下限(10S/N)在0.05~0.1mg·kg-1之间。加标回收率在73.2%~122%之间,相对标准偏差(n=6)在0.49%~11%之间。 相似文献
13.
二英类分析研究进展及展望 总被引:4,自引:0,他引:4
通过综合介绍国内外二英类物质分析研究的最新动态,包括二英类的前处理和气相色谱法(GC)、液相色谱法(LC)、胶束电动色谱法(MEKC)、质谱法(MS)、气相色谱/质谱(GC/MS)联用和生物分析法等多种分析技术及其改进方法,指出了二英类分析研究工作中现存的问题,对今后的发展动向提出了一些建议. 相似文献
14.
15.
Analysis of acrylamide in food by isotope-dilution liquid chromatography coupled with electrospray ionization tandem mass spectrometry 总被引:1,自引:0,他引:1
A confirmatory method for the determination of low levels of acrylamide in different food products is presented. The method entails extraction of acrylamide with water, precipitation of matrix constituents with acetonitrile, and two clean-up steps consecutively over Isolute Multimode and cation-exchange cartridges. The final extract is analyzed by liquid chromatography (LC) coupled to positive electrospray ionization tandem mass spectrometry employing [13C3]-acrylamide as internal standard. For the chromatographic step, a LC column based on a polymethacrylate gel is employed which shows good retention of acrylamide under isocratic flow conditions (k' = 1.2). Mass spectral acquisition is done by selected reaction monitoring, choosing the characteristic transitions m/z 72-->55, 72-->54 and 72-->27. In-house validation data for breakfast cereals and crackers show good precision of the method, with intra- and interassay variation below 10%. The limits of detection for crackers and breakfast cereals, respectively are estimated at 15 and 20 microg/kg, and recoveries of fortified samples ranged between 58 and 76%. Furthermore, the method is applicable to a number of different food products, including biscuits, crisp bread, wafers, confectionery cocoa liquor, and nuts. Finally, the good results obtained in several small-scale interlaboratory tests provided additional confidence in the performance of the method. 相似文献
16.
17.
K. P. Naikwadi F. W. Karasek 《International journal of environmental analytical chemistry》2013,93(3):329-342
Abstract Positive identification and quantitation of polychlorinated dibenzo-p-dioxins (PCDD) in complicated environmental samples is described using a C-13 labelled dioxin mixture as an internal reference standard. Environmental samples are spiked with the C-13 labelled dioxin mixture and monitored for labelled and unlabelled dioxins using GC-MS in the electron impact selected ion monitoring (EISIM) mode. The C-13 labelled dioxin mixture and a municipal solid waste (MSW) incinerator fly ash extract show the same number of isomers in each tetra to octa-chlorodioxin congener groups. Quantitation of the C-13 labelled dioxin mixture was carried out using a reference standard mixture of unlabelled dioxins consisting of at least one isomer for each congener group. The C-13 labelled dioxin standard is highly useful for the determination of retention windows for tetra- to octa-chlorodioxins, identification of dioxins in each congener group, and calculation of the recovery of dioxins in samples that require extensive sample clean-up prior to GC-MS analysis. Its application for retention time window determination and as an internal reference standard for quantitation of dioxins in MSW incinerator fly ash extract and identification of dioxins in a complex sample from a PCB fire is demonstrated. 相似文献
18.
痕量铼的同位素稀释中子活化分析 总被引:6,自引:2,他引:6
将同位素稀释法的准确性与中子活性分析(NAA)的高灵敏度相结合,建立了一种新的痕量铼的测试方法,实验中对Re的检出限为0.004ng,全流程空白为0.05ng,地于Re含量为64ng/g的样品,在取样量为50mg时,单次测定误差(2σ)为3.1%,测定Re一为30ng/g的样品,本方法的2σ在3%以内,4次分析的RSD为4.1%,而采用一般的NAA,结果偏低约20%,并且RSD大于5%。 相似文献
19.
20.
Point D Davis WC Christopher SJ Ellisor MB Pugh RS Becker PR Donard OF Porter BJ Wise SA 《Analytical and bioanalytical chemistry》2007,387(7):2343-2355
An accurate, ultra-sensitive and robust method for speciation of mono, di, and tributyltin (MBT, DBT, and TBT) by speciated isotope-dilution gas chromatography-inductively coupled plasma-mass spectrometry (SID-GC-ICPMS) has been developed for quantification of butyltin concentrations in cryogenic biological materials maintained in an uninterrupted cryo-chain from storage conditions through homogenization and bottling. The method significantly reduces the detection limits, to the low pg g(-1) level (as Sn), and was validated by using the European reference material (ERM) CE477, mussel tissue, produced by the Institute for Reference Materials and Measurements. It was applied to three different cryogenic biological materials-a fresh-frozen mussel tissue (SRM 1974b) together with complex materials, a protein-rich material (whale liver control material, QC03LH03), and a lipid-rich material (whale blubber, SRM 1945) containing up to 72% lipids. The commutability between frozen and freeze-dried materials with regard to spike equilibration/interaction, extraction efficiency, and the absence of detectable transformations was carefully investigated by applying complementary methods and by varying extraction conditions and spiking strategies. The inter-method results enabled assignment of reference concentrations of butyltins in cryogenic SRMs and control materials for the first time. The reference concentrations of MBT, DBT, and TBT in SRM 1974b were 0.92 +/- 0.06, 2.7 +/- 0.4, and 6.58 +/- 0.19 ng g(-1) as Sn (wet-mass), respectively; in SRM 1945 they were 0.38 +/- 0.06, 1.19 +/- 0.26, and 3.55 +/- 0.44 ng g(-1), respectively, as Sn (wet-mass). In QC03LH03, DBT and TBT concentrations were 30.0 +/- 2.7 and 2.26 +/- 0.38 ng g(-1) as Sn (wet-mass). The concentration range of butyltins in these materials is one to three orders of magnitude lower than in ERM CE477. This study demonstrated that cryogenically processed and stored biological materials are a promising alternative to conventional freeze-dried materials for organotin speciation analysis, because these are, at present, the best conditions for minimizing degradation of thermolabile species and for long-term archival. Finally, the potential of the analytical method was illustrated by analysis of polar bear (Ursus maritimus) and beluga whale (Delphinapterus leuca) liver samples that had been collected in the Arctic and archived at the Marine Environmental Specimen Bank. Significant concentrations of butyltin compounds were found in the samples and provide the first evidence of the presence of this class of contaminant in the Arctic marine ecosystem. Figure Eye catch image. 相似文献