Method for the determination of selected organochlorine pesticides and polychlorinated biphenyls in human serum based on a gel permeation chromatographic clean-up

A gel permeation chromatographic (GPC) clean-up based method was developed for determination of selected organochlorine pesticides and polychlorinated biphenyls in human serum. The method permits automation of the sample extract clean-up stage and is designed to work with small amounts of sample. Different working variables were studied in its development, including injection volume, flow rate, and fat amount as the most representative coextract. The method provides solvent and time savings. Initial extraction was performed using 96-well solid-phase disk extraction plates, and quantification was performed by gas chromatography with electron capture detection and mass spectrometry. Recoveries of PCB congeners 28, 52, 101, 118, 138, 153, and 180 and organochlorine pesticides HCB, β-HCH, γ-HCH, heptachlor epoxide, p,p′-DDE, and p,p′-DDT at two spiking levels ranged from 55% to 115% with relative standard deviations ranging from 2.0% to 14.6%. Limits of quantification ranged from 0.06 to 0.16 ng mL⁻¹ for PCBs and from 0.12 to 0.36 ng mL⁻¹ for organochlorine pesticides. Finally, the method was applied to the analysis of 38 serum samples and the results were compared with those of another procedure validated at the laboratory.     

Serum levels of organochlorine pesticides in healthy adults from five regions of Spain

The aim of this study was to measure of serum levels of p,p′-dichlorodiphenyl trichloroethane (p,p′-DDT), p,p′-dichlorodiphenyl dichlorethylene (p,p′-DDE), β-hexachlorocyclohexane (β-HCH), and hexachlorobenzene (HCB) in healthy adults in Spain. Furthermore, we also analyzed these levels according to dietary, other lifestyle factors and anthropometric characteristics. We measured the concentrations of such organochlorine pesticides (OCPs) in serum samples collected during 1992–1996 from 953 subjects aged 35–64 years, they were residents of five Spanish regions, they were randomly selected from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. OCPs were determined by means of gas chromatography with electron-capture detection (GC-ECD). The most frequent compound found in serum was p,p′-DDE, present in 98% of the samples, followed by HCB and β-HCH, found in 89% and 77% of samples, respectively, while p,p′-DDT could be measured only in 26% of subjects. The geometric means of serum concentrations (ng/g lipid) were 822 for p,p′-DDE, 167 for β-HCH, and 379 for HCB. The concentrations of all OCPs were positively associated with age and body mass index, and decreased along the period of blood collection. No association was found between OCPs levels and dietary factors. The concentrations of p,p′-DDE and β-HCB were higher in Murcia, one of southern regions, most likely associated with intensive past use of pesticides related to agricultural practices, while higher levels of HCB were found in Navarra, located in the north, maybe due to industrial use rather than agricultural application.     

Establishment of control site baseline data for erosion studies using radionuclides: a case study in East Slovenia

The aim of the present study was to establish a reference site and its soil characteristics for use of fallout radionuclides in erosion studies in Slovenia. Prior to this study, no reference site and baseline data existed for Slovenia for this purpose. In the agricultural area of Gori?ko in East Slovenia, an undisturbed forest situated in Šalamenci (46°44’N, 16°7’E), was selected to establish the inventory value of fallout ¹³⁷Cs and to establish a baseline level of multi-elemental fingerprint (major, minor, trace elements including heavy metals) and naturally occurring radionuclides in soils. A total of 20 soil profiles were collected at four 10 cm depth increments for evaluation of baseline level of ¹³⁷Cs inventory. An exponential distribution for ¹³⁷Cs was found and the baseline level inventory was established at 7300 ± 2500 Bq m⁻² with a coefficient of variation of 34%. Of this mean present-day inventory, approximately 45% is due to the Chernobyl contribution.The physical degradation of soils through erosion is linked with biochemical degradation. This study introduces an approach to establishment of the naturally occurring radionuclide and elemental fingerprints baseline levels at a reference site which can provide comparative data to those from neighbouring agricultural fields for assessment of soil redistribution magnitude using fallout radionuclides. In addition, this information will be used to determine the impact of soil erosion processes and agricultural practices on soil quality and redistribution within agricultural landscapes in Slovenia.