This article reviews the available literature on the analysis of brominated dibenzo-p dioxins and furans (PBDD/Fs) by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). Sample extraction and clean up, injection techniques, chromatographic separation, labelled standards and QA/QC works are discussed. Furthermore, full separation of PBDD/Fs from polybrominated diphenyl ethers (PBDEs) during clean up and control of possible chromatographic interference of PBDEs during instrumental analysis as well as possible actions to further enhance the quality of published data are discussed in detail. 相似文献
A column chromatography procedure was developed for the clean-up of solvent-extracted sediment samples for the fractionation of polybrominated diphenyl ethers (PBDEs) and polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs). The procedure included multiple column chromatography steps for clean-up for the separation of PBDEs from PBDD/Fs. The separation of the two chemical groups overcame the mutual interfering problem during the GC-ion trap MS analysis. The method was validated with the analysis of quality control samples. The method accuracy represented with relative error was less than 16% for all targeted PBDEs and PBDD/Fs congeners. Recoveries of the 13C-labeled standards ranged from 64% to 117% with relative standard deviation from 7.3% to 15%. Results from the analysis of environmental sediment samples collected in the vicinity of a recycling site for electronic wastes showed high levels of PBDEs (1.5-12 ng/g, dry weight), trace levels of PBDFs (0.025-0.92 ng/g, dry weight) and non-detectable PBDDs. 相似文献
The aim of this work was to implement a chemometric analysis to detect the relationships between the analysed variables in samples of solid fuels. Efforts are being made to apply chemometrics methods in environmental issues by developing methods for the rapid assessment of solid fuels and their compliance with the required emission characteristics regulations. In the present investigation, two clustering techniques—hierarchical clustering analysis (HCA) and principal components analysis (PCA)—are used to obtain the linkage between solid fuel properties and the type of sample. These analyses allowed us to detect the relationships between the studied parameters of the investigated solid fuels. Furthermore, the usefulness of chemometrics methods for identification of the origin of biofuels is shown. These methods will enable control of the degree of contamination. 相似文献
Since the discovery of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs) in the process of municipal solid waste incineration(MSWI),a large number of researches have been conducted to reveal their formation mechanisms and emission characteristics.As one of national priority control pollutants,chlorinated organics are inclined to transfer into PCDD/Fs in the heterogeneously catalyzed process,which has been considered to be one of great challenges in environmental catalysis.However,so far direct evidences to support such a conversion process are insufficient,and the reaction mechanisms are lack of exploration.This study investigated the catalytic elimination of chlorobenzene(CBz) over a range of industrially applied active species including Pt,Ru,V,Ce and Mn oxides,and explored their reaction byproducts,chlorine adsorption/desorption behaviors and PCDD/F formations.We found that all of these species could generate the PCDD/Fs,amongst which,Mn species were the most active for PCDD/F formation.Approximately 140 ng I-TEQg-1 PCDD/Fs were detected on the Mn-CNT surface after ageing at250℃ for 30 h.Even using the dichloromethane(DCM) as a precursor,significant PCDD/Fs were still detected.The Ru and V species were shown to generate much less polychlorinated byproducts and PCDD/Fs,owning to their sufficiently high abilities in Cl desorption,which were through the semi-Deacon and Br(?)nsted H reactions,respectively. 相似文献
There is a need for cost-efficient alternatives to gas chromatography (GC)–high-resolution mass spectrometry (HRMS) for the
analysis of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs) in food and feed. Comprehensive two-dimensional
GC–micro electron capture detection (GC×GC-μECD) was tested and all relevant (according to the World Health Organisation,
WHO) PCDD/Fs and PCBs could be separated when using a DB-XLB/LC-50 column combination. Validation tests by two laboratories
showed that detectability, repeatability, reproducibility and accuracy of GC×GC-μECD are all statistically consistent with
GC-HRMS results. A limit of detection of 0.5 pg WHO PCDD/F tetrachlorodibenzo-p-dioxin equivalency concentration per gram of fish oil was established. The reproducibility was less than 10%, which is below
the recommended EU value for reference methods (less than 15%). Injections of vegetable oil extracts spiked with PCBs, polychlorinated
naphthalenes and diphenyl ethers at concentrations of 200 ng/g showed no significant impact on the dioxin results, confirming
in that way the robustness of the method. The use of GC×GC-μECD as a routine method for food and feed analysis is therefore
recommended. However, the data evaluation of low dioxin concentrations is still laborious owing to the need for manual integration.
This makes the overall analysis costs higher than those of GC-HRMS. Further developments of software are needed (and expected)
to reduce the data evaluation time. Combination of the current method with pressurised liquid extraction with in-cell cleanup
will result in further reduction of analysis costs.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
Screening serum for the presence of prostate specific antigen (PSA) belongs to the most common approach for the detection of prostate cancer. This review (with 156 refs.) addresses recent developments in PSA detection based on the use of various kinds of nanomaterials. It starts with an introduction into the field, the significance of testing for PSA, and on current limitations. A first main section treats electrochemical biosensors for PSA, with subsections on methods based on the use of gold electrodes, graphene or graphene-oxide, carbon nanotubes, hybrid nanoparticles, and other types of nanoparticles. It also covers electrochemical methods based on the enzyme-like activity of PSA, on DNA-, aptamer- and biofuel cell-based methods, and on the detection of PSA via its glycan part. The next main section covers optical biosensors, with subsections on methods making use of surface plasmon resonance (SPR), localized SPR and plasmonic ELISA-like schemes. This is followed by subsections on methods based on the use of fiber optics, fluorescence, chemiluminescence, Raman scattering and SERS, electrochemiluminescence and cantilever-based methods. The most sensitive biosensors are the electrochemical ones, with lowest limits of detection (down to attomolar concentrations), followed by mass cantilever sensing and electrochemilumenescent strategies. Optical biosensors show lower performance, but are still more sensitive compared to standard ELISA. The most commonly applied nanomaterials are metal and carbon-based ones and their hybrid composites used for different amplification strategies. The most attractive sensing schemes are summarized in a Table. The review ends with a section on conclusions and perspectives.
Graphical abstract Schematic representation of nanostructure-based biosensors for detection of prostate specific antigen using various detection schemes and biorecognition elements such as antibodies (Abs), aptamers (APT), lectins (LEC), and molecularly imprinted polymers (MIP).
