PCDFs sampling

Buser and Bosshardt reported on the results of a survey on the PCDD and PCDF contents of pentachlorophenol (PCP) and PCP-Na from commercial sources in Switzerland (UO). From the results, the grouping of the samples into two series can be observed a first series with generally low levels (hexa-CDD < 1 ppm) and a second series with much higher levels (hexa-CDD > 1 ppm) of PCDDs and PCDFs. Samples of high PCDD contents had also high PCDF contents. For most samples, the contents of these contaminants were in the order tetra- penta < hexa < hepta octa--CDD/CDF. The ranges of the combined levels of PCDDs and PCDFs were 2-l6 and 1-26 ppm, respectively, for the first series of samples, and 120-500 and 85 570 ppm, respectively, for the second series of samples. The levels of octa-CDD and octa-CDF were as high as 370 and 300 ppm, respectively (UP). 

For the quantitative determination of polychlorinated diben-zodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), sample treatment and conservation play crucial roles, too. Only some of the 75 PCDD isomers and 135 PCDF isomers are highly toxic. The collection and analysis of the hazardous compounds present at ultratrace levels in environmental samples must preferably be isomer-specific. The exposure routes for these compounds originate from combustion processes (18-19). 

In general, capillary gas chromatography provides enough resolution for most determinations in environmental analysis. Multidimensional gas chromatography has been applied to environmental analysis mainly to solve separation problems for complex groups of compounds. Important applications of GC-GC can therefore be found in the analysis of organic micropollutants, where compounds such as polychlorinated dibenzodioxins (PCDDs) (10), polychlorinated dibenzofurans (PCDFs) (10) and polychlorinated biphenyls (PCBs) (11-15), on account of their similar properties, present serious separation problems. MDGC has also been used to analyse other pollutants in environmental samples (10, 16, 17). 

PCCD/PCDFs have been found to be present in Arctic air samples, e.g. during the winter of 2000/2001 in weekly filter samples (particulate phase) collected at Alert in Canada. PCDD/PCDFs have been monitored since 1969 in fish and fish-eating birds from the Baltic. The levels of PCDD/PCDFs in guillemot eggs, expressed as TEQ, decreased from 3.3 ng/g lipids to around 1 ng/g between 1969 and 1990. Since 1990, this reduction seems to have levelled off and today it is uncertain whether there is a decrease or not. Fish (herring) show a similar picture. 

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. 

Two-dimensional GC can be used to separate complex mixtures of polyaromatic compounds, and MS used to subsequently identify the compounds. In this method, the original sample is injected into a gas chromatograph with one type of column. As the components exit the first GC, they are fed into a second GC, with a different column, for further separation and finally into a mass spectrometer. In this way, compounds that coeluted from the first column are separated on the second. Focant et al. [19] were able to separate polychlorinated dibenzo-p-dioxin (PCDD), polychlorinated dibenzofuran (PCDF), and coplanar polychlorinated biphenyl (cPCB) using this type of analytical procedure, including isotope dilution TOF-MS. These compounds are frequently found as contaminants in soils surrounding industrial settings thus, the ability to separate and identify them is extremely important [6,12,19],... 

TEQ calculations were made based on both - the WHO-TEFs and I-TEFs for seventeen 2,3,7,8-substituted PCDDs and PCDFs. Dioxin like PCBs were not measured. Total WHO-TEQ PCDD/F values for the analyzed samples range from 53.50 to 65.26 ng/kg dry mass. Calculations, based on I-TEFs were also made, to allow comparison with the literature data. The variation in the TEQ concentration may be attributed to varying loads during the sample collection period. Obtained results are higher, than medium... 

Naf, C., Broman, D., Ishag, R., Zebuhr, Y., PCDDs and PCDFs in water, sludge and air samples from various levies in a waste water treatment plant with respect to composition changes and total flux, Chemosphere 20,1990,1503-1510. 

Bergqvist, P.-A. Strandberg, B. R pe, C. 1998, Lipid removal using semipermeable membranes in PCDD and PCDF analysis of fat-rich environmental samples. Chemosphere 38 933—943. 

Sampling rates at different temperatures have been determined by Huckins et al. (1999) for PAHs at 10,18, and 26 °C, by Rantalainen et al. (2000) for PCDDs, PCDFs, and non-ortho chlorine substituted PCBs at 11 and 19 °C, and by Booij et al. (2003a) for chlorobenzenes, PCBs, and PAHs at 2,13 and 30 °C. The effect of temperature on the sampling rates can be quantified in terms of activation energies (A a) for mass transfer, as modeled by the Arrhenius equation... 

Figure 3.5 Sampling rates at 15 4 °C as a function of log Kov, for PCBs—open circles Meadows et al. (1998), PAHs—closed circles Huckins et al. (1999), closed triangles Huckins et al. (2004) chlorobenzenes/PCBs/PAHs—open triangles Booij et al. (2003a) HCHs/HCB— diamonds Vrana and SchCiurmann (2002) non-ortho PCBs/PCDDs/PCDFs—asterisks Rantalainen et al., 2000) and pesticides—squares Huckins et al. (2002b).

For the determination of the intralaboratory repeatability of the DR CALUX bioassay for sediment samples, two sediment extracts were analyzed 10 times. Each analysis was performed in triplicate. As a prerequisite for a correct triplicate analysis, the percentage standard deviation in the triplicate determination should be below 15%. This is in accordance with the harmonized quality criteria for eell-based bioassay analyses of PCDDs/PCDFs in feed and food as formulated by Behnisch et al. (Behnisch et al, 2001 a) and as detailed in European Union directive 2002/69/ EC and direetive 2002/70/EC. The repeatability for the low-2,3,7,8-TCDD-content sediment... 

A similar relationship between PCDF isomers retained and apparently excreted has been observed for patients with the Yusho disease, an intoxication by a rice oil contaminated with PCBs and PCDFs. The contaminated rice oil and liver samples from two of the patients were analyzed and all the major PCDFs were identified. A comparison revealed that none of the isomers retained had two vicinal hydrogenated C-atoms in any of the two... 

In analyses using high-resolution GC/MS and MS confirmation, Rappe et al. (35.1 and Norstrom et al. (30) have reported that in other samples of Herbicide Orange, as well as in European and US 2,U,5-T formulations from the 1950 s and 1960 s, 2,3,7,8--tetra-CDD was the dominating compound of this group. Only minor amounts of other PCDDs and PCDFs could be found, primarily lower chlorinated PCDDs in samples of Herbicide Orange, see ref 35. 

Rappe et al. have reported on the analysis of two commercial chlorophenate formulations from Scandinavian sources using a 50. m OV-17 column (7). The tetrachlorophenol was known to contain approximately 5 2,U,6-tri-, 50 2,3,l, 6-tetra- and 10 pentachlorophenol as their sodium salt. The combined levels of PCDDs and PCDFs (tetra- to octa-) were 10 and l60 yg/g, respectively. Whereas on the earlier analyzed PCP samples 0 0 ] the... 

Using the same analytical technique the major PCDFs in the Scandinavian 2,U,6-trichloro- and 2,3,, 6-tetrachlorophenol samples have been identified and quantified. In addition a US PCP-Na formulation was also analyzed, and the quantitative results are collected in Table III (7.) In this table we have also included the results of a few other investigations (17, Ul). 

The chlorophenols in the formulations analyzed differed in their degree of chlorination and were likely synthesized in different ways. Nevertheless, the same penta-, hexa- and hepta-CDF isomers were found as the main PCDF components in all three samples although in somewhat different proportions (7.), see Figure... 

D. PCBS. Vos et al. in 1970 were able to identify PCDFs (tetra- and penta-CDFs) in two samples of European PCBs but not in a sample of Aroclor 1260 (k2). The toxic effects of the PCBs were found to parallel the levels of PCDFs present. Bowes et al. examined a series of Aroclors as well as the samples of Aroclor 12 0, Phenoclor DP-6 and Clophen A-60, that had previously been analyzed ( 2). They used packed column GC and mass spectrometry, and found that the most abundant PCDFs had the same retention time as 2,3,7 8-tetra- and 2,3 , 7 8-penta-CDF their results are collected in Table IV 0 3). Using high-resolution GC and MS, Rappe and Buser (unpublished) have analyzed a number of commercial PCBs, and the results are also collected in Table IV. In general the PCBs contained quite a complex mixture of PCDFs, up to UQ different isomers. The highest level of PCDFs was found in a Japanese PCB used for two years in a heat exchange system, which was found to have about 10 yg/g. The dominating isomer was identified as P j tetra-CDF at a level of 1.25 yg/g (UU ]. 

E. Fly ash. Olie et al. reported in 1977 on the occurrence of PCDDs and PCDFs in fly ash and flue gas samples from municipal incinerators in the Netherlands (UjO. No quantitative data were given in this report, but Buser and Bosshardt made a... 

One of the branches under study is the saw-mill industry. In Finland 2,3,, 6-tetrachlorophenol is used for bluestain control of the timber during the summer season (May - OctoberI. It is known that PCDFs are the major contaminants in this particular formulation, see Table III. The sampling was performed twice, the first set of samples was taken after 6 months of non-exposure. The other sampling was performed after one month of chlorophenol exposure. In Table VIII we have collected the levels of chlorophenols found in the urine samples as well as the levels of PCDDs and PCDFs found in the blood samples. 

Table VIII. Levels of PCDDs and PCDFs in blood samples from workers in...

PCDDs and PCDFs were also found at similar levels in-blood following a 6-8 months1 long period of non-exposure as compared to samples taken after one month of exposure, although the level of chlorophenols in the urine increased up to 100 times after the period of exposure. Consequently no good correlation was found between the blood and urine analyses. 

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