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Dioxins analysis

The dichlorodibenzo-p-dioxin component was isolated by passing a dioxane solution of the mixture through acetate ion exchange resin to remove phenolics. The eluted product was recrystallized from benzene. The x-ray powder diffraction pattern of the precipitate was identical with that of 2,7-dichlorodibenzo-p-dioxin. Analysis of the mother liquor by GLC showed a singular peak consistent with 2,7-dichlorodibenzo-p-dioxin. The mother liquor was cooled to 5°C and yielded transparent crystals. This material had an x-ray diffraction pattern congruent to a sample of 2,8-dichlorodibenzo-p-dioxin obtained from A. E. Pohland (FDA). The two patterns were quite distinct from each other 14, 15). [Pg.133]

Several attempts have been made to set up immunochemical techniques for dioxin analysis (reviewed in [230,238,239]). Frequently the detectability and selectivity accomplished have not been considered appropriate for the direct analysis of environmental samples. We should notice that due to the poor solubility of PCDDs and PCDFs in water, the levels of these contaminants in aqueous samples is very low. For this reason analysts usually prefer the use of chromatographic and spectrometric methods that perform using organic solvents. However, the speed and high sample throughput that can be accomplished with the immunochemical methods have prompted several research groups and companies to establish immunochemical methods. [Pg.159]

Tanaka K, Hara S, Makino S. 1992. Development of new program for dioxin analysis using mass spectrometry. Kankyo Kagaku 2(2) 428-9. [Pg.694]

Kociba RJ (1987), in Solving Hazardous Waste Problems - Learnings from Dioxins" Analysis of animal toxicity studies of 2,3,7,8-tetrachlorodibenzo-p-dioxin , p. 54-67, Exner JH (Ed.), American Chemical Society, Washington DC... [Pg.12]

Hockel J, Hagenmaier H (1995), Organohalogene Compounds 23 139-140.. .Selective separation of 2,3,7,8 - Substituted tetra to hexa CDD/CDF from other PCDD/PCDF by fractionation on Alumina. B Super I for Dioxin Analysis", Eds. Droxin 95 Secretariat, Edmonton, Canada, ISBN 3-928379-13-5... [Pg.80]

Apart from GPC with Bio-Beads, there are other automated clean-up approaches. Although GPC has several advantages, Focant and co-workers claimed that for the high-fat-content samples (4 g lipids) required in dioxin analysis, GPC suffered from several practical limitations and therefore could not be performed 100% automatically (59). Consequently, new high-capacity disposable silica (HCDS) columns were developed for the Power-Prep system. The combination of PLE and Power-Prep clean-up allowed 10 dioxin samples to be analyzed in 48 hrs. [Pg.133]

The third method involved equilibration of dioxin present in a compact film on a glass slide, (formed by evaporation of dioxin dissolved in hexane), with water in a 2 liter volumetric flask. A glass stirrer was used for mixing the contents. To avoid problems with the formation of an interfacial film, the flask was rigorously cleaned with boiling concentrated nitric acid, and the cleaned flask was filled to the neck with water for equilibration. A capillary GC/MS method was used for dioxin analysis. Solubility results using this method are given in Table III. [Pg.107]

Brenner, K. S., I. H. Dorn, and K. Herrmann. 1986. Dioxin analysis in stack emissions, slags and the wash water circuit during high-temperature incineration of chlorine-containing industrial wastes Part 2. Chemosphere 75(9-12) 1193-99. [Pg.344]

MS has been the leading technique used in dioxin analysis. Until the 1990s, ultratrace determinations of polychlorinated dibenzo-p-dioxins and furans (PCDDs/Fs) were routinely performed using GC-HRMS, operating in the El mode (electron energy... [Pg.2921]

Sensitivity strictly refers to the slope of the calibration curve for the method but is widely used (including in this book) in a more general sense of a low value for the limit of detection (LOD, the lowest concentration of an analyte that the bioanalytical procedure can reliably differentiate from background and noise, see discussion in Section 8.4.1). Sensitivity can also refer to the lower limit of quantitation (LLOQ, the lowest amount of an analyte in a sample that can be quantitatively determined with acceptable precision and accuracy. Section 8.4.2). While it is true that a higher sensitivity in the strict sense can lead to lower values of LOD and LLOQ, the latter parameters also vary with the level of chemical background and statistical noise (see discussion of Figure 8.10 in Section 8.4). While the LLOQ is usually the more important parameter in quantitative analyses, the LOD can be significant for some applications (e.g. dioxin analysis. Section 11.4.1). [Pg.542]

For GC-HRMS, El with a nominal electron energy 30eV is generally used for dioxin analysis instead of the otherwise almost universal 70 eV. Although such a decrease of electron energy results in a decrease in the total ionization yield, this is more than compensated... [Pg.631]

Laboratory diagnosis. Clinical signs alone are insufficient to establish a diagnosis. Analysis ot tissues is necessary to confirm exposure unfortunately, few laboratories offer routine dioxin analysis. [Pg.222]

Spinnel et cd. further developed the modular PFE approach for dioxin analysis. A matrbc retainer module filled with sulfuric acid impregnated silica gel was introduced between the sample. In this case, salmon muscle was mixed with sodium sulfate and the carbon trap. This procedure provided extracts clean enough to be analysed by GC-HRMS (high-resolution mass spectrometry) analysis after solvent evaporation to an appropriate final volume. [Pg.24]

High and Low Mass Resolution In the Case of Dioxin Analysis... [Pg.254]

Can dioxin analysis be carried out with quadrupole and ion trap instruments ... [Pg.254]

High mass resolution is therefore also required to verify positive screening results in dioxin analysis (see also section 4.29). A comparison of the two spectrometric methods of the lower and higher resolution SIM techniques is shown in Figure 2.192 for the mass traces in the detection of TCDF (tetrachlorodibenzofuran) traces. [Pg.257]

A reference compound is leaked continuously from the reference inlet system during the GC run into the ion source. Typically perfluoro-tributylamine (FC43) is used as reference compound in HRGC-HRMS for dioxin analysis. Other reference compounds may be used to suit individual experimental conditions. [Pg.301]

A typical example for extended use of the isotope dilution method is the quantification of polychlorinated dioxins. Sixfold and twelvefold labeled dioxins and furans in the required chlorination degrees are used as recovery and surrogate standards during sample preparation and GC-MS analysis, as described in the widely applied EPA 1613 method. The nearly identical compound characteristics during clean-up, the chromatographic process and detection, guarantees most reliable quantitation results based on the sample individual recovery values in one analysis run (see details in the application Section 4.14 on dioxin analysis). [Pg.476]

The applications given here have been chosen in order to describe typical areas of use of GC-MS, such as air, water, soil, foodstuffs, the environment, waste materials, drugs or pharmaceutical products. Special emphasis has been placed on current and reproducible examples which give successful templates for routine laboratories. The selection cannot be totally representative of the use of modern GC-MS, but shows the main areas into which the methodology has spread and will continue to do so. In addition, in special areas of application, such as the analysis of isotope-specific measuring procedures and the isotope dilution method for dioxin analysis are described. [Pg.493]

A compound for quantitative reference not contained in the sample with chemical characteristics similar to those of the analyte. Labeled analogues of the target analytes are typically applied, for example, in dioxin analysis. The ISTD provides an analytical response that is distinct from the analyte and not subject to interference. Internal standards are used to adjust for variations in the analytical response due to... [Pg.798]


See other pages where Dioxins analysis is mentioned: [Pg.540]    [Pg.1253]    [Pg.1253]    [Pg.36]    [Pg.231]    [Pg.403]    [Pg.89]    [Pg.238]    [Pg.267]    [Pg.275]    [Pg.874]    [Pg.265]    [Pg.433]    [Pg.619]    [Pg.853]    [Pg.854]    [Pg.855]    [Pg.857]    [Pg.1914]    [Pg.3770]    [Pg.629]    [Pg.631]    [Pg.631]    [Pg.403]    [Pg.257]    [Pg.257]    [Pg.303]    [Pg.800]   
See also in sourсe #XX -- [ Pg.255 ]

See also in sourсe #XX -- [ Pg.169 ]




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