[No abstract available]

We have analyzed 19 samples of human adipose tissue obtained from general population of Madrid (Spain), determining the levels of tetra- to octachlorinated dibenzo-p-dioxins and -furans. We found that PCDD are present in higher concentrations than PCDFs, with the levels for PCDDs increasing by about two orders of magnitude with chlorination, from tetra- to octa-. The distribution of PCDFs among groups of congeners was more uniform than that of PCDDs. The concentration of penta-, hexa- and hepta-congeners was usually below 70 pg/g. Levels and patterns of PCDDs and PCDFs in Spanish adipose tissues were similar to those found in other industrialized countries. © 1993.

[No abstract available]

The modified sequential simplex method was applied to optimize the oven temperature programming of a single-column gas chromatography procedure developed to determine polychlorinated biphenyl congeners in a mixture of technical Aroclors. Both the overall resolution of fourteen congeners of interest and the time of analysis were taken into account in the optimization. Successful seperations of some clusters usually unresolved with a single column have been obtained. © 1992.

Human adipose tissue samples collected in Madrid (Spain) were analyzed to understand the levels of organochlorine insecticides and polychlorinated biphenyls (PCBs); p,p’-DDE, the major metabolite of p,p’-DDT, and PCBs were found in all samples and the mean value was 8.48 and 0.87 mg/kg fat weight, respectively. Mean values for a-HCH, j8-HCH, y-HCH, hexachlorobenzene (HCB), heptachlor epoxide, dieldrin, dichlorobenzophenone (DBP), p,p’-TDE, and p,p’-DDT also are given. Aldrin, heptachlor, chlordane, and mirex were not found in any of the fat samples. Concentrations of organochlorine compounds in human adipose tissue samples in this paper were lower than those taken previously in Spain and proves the effectiveness of regulatory actions adopted. No relation was found between the organochlorine compounds content and the donors sex. Significant differences were observed between most persistent fat-soluble compounds (p,p‘-DDT, p,p’-DDE, and PCBs) and the donors age. © 1992, Taylor & Francis Group, LLC. All rights reserved.

The direct zonal on-column injection method was applied to a high-performance liquid chromatographic study of pollutant-protein binding interactions in solution. The protein and the protein-ligand complex are excluded on the basis of the size from the diol support, and the free ligand penetrates into the pores and is more retained. The pattern of the ligand elution profile depends on the protein ligand dissociation constant. This effect was quantitatively analysed by developing a numerical simulation algorithm in which the column is divided into slices of given thickness. The column length, flow-rate and shape of the injection signal are given as input parameters. A global dispersion coefficient accounts for peak broadening. A rapid equilibrium is assumed with the hypothesis that a monovalent ligand interacts with a single binding site on the protein. The interaction of bovine serum albumin with pentachlorophenol was studied, and an apparent dissociation constant for the protein-ligand complex was determined by fitting the theoretical profile to the experimental one. The effect of the acetonitrile content in the solvent was studied. An important decrease of the dissociation constant is observed that affects the chromatographic elution pattern. © 1992 Elsevier Science Publishers B.V.

The separation of fifteen standard isomers of polychlorodibenzofurans (PCDFs) and polychlorodibenzo-p-dioxins (PCDDs) with a 2,3,7,8-substitution pattern by high-performance gas chromatography using capillary columns with bonded phases was studied in order to obtain better resolutions than those usually reported. The modified simplex method was used to improve the overall separation achievable with the analytical procedure by optimizing the experimental conditions that affect chromatographic resolution. © 1991.

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in human fat and milk samples arise from a variety of sources. It is generally assumed that food intake is mainly responsible for the presence of these contaminants in man. Data on levels in food samples are, however, relatively rare. This review reports the levels found in various foodstuffs which are easily obtained in daily life. From the data, it is clear that most animal foodstuffs have already been contaminated by these contaminants, even though in very small amounts. However, the plant products are free of most PCDDs and PCDFs. It is difficult to evaluate the different sources of contamination of food, but municipal solid waste incinerators and chlorophenol industries are likely to be the most important sources. © 1990.

PCDDs, PCDFs and PCBs have been analysed in soil samples where waste electrical equipment has been burned directly on the ground in three locations of Burgos (Spain). High levels of PCDDs, PCDFs and PCBs were detected in the centre of combustion sites. The results show PCB levels between 0.824 and 1.240 µg/g, and PCDDs and PCDFs levels between 8.73–36.37 ng/g and 12.79–50.95 ng/g. The I-TEF values between 2.96–9.15 for dioxins and furans indicate that these soils are heavily polluted and may represent a risk for human and animal health. © 1991, Taylor & Francis Group, LLC. All rights reserved.

An exhaustive extraction and a good clean-up method for analysis of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in incinerator fly ash is presented. After Soxhlet extraction of the fly ash with benzene, a multi-step clean-up is necessary to remove all interferences from the sample. The principal problem is the separation of PCDDs and PCDFs from the polychlorinated biphenyls. There are two key conditions: the alumina activation and the polarity of the solvents used. The recovery of the PCDDs and PCDFs is good, ranging from 87.1 to 118 percent. © 1990.

A principal components multivariate statistical approach (SIMCA) was used to examine complex mixtures of polychlorinated biphenyl residues (PCBs) in fly ash from municipal incinerators.