Novel pressurized solvent extraction vessels for the analysis of polychlorinated biphenyl congeners in avian whole blood

Field confirmation of modified pressurized solvent extraction vessels for the analysis of polychlorinated biphenyl congeners in blood samples from Great Lakes Mallards (Anas platyrhynchos)

Miniaturized pressurized solvent extraction vessels were used to examine polychlorinated biphenyl congener (PCB) concentrations in 0.2 g sample sizes of whole blood, liver, heart and breast tissue sampled from twelve Great Lakes Mallard ducks (Anas platyrhynchos). This study successfully supported the blood extraction method, previously validated only using laboratory prepared blood samples, using field samples. In situ clean-up offered excellent sample throughput without degradation of GC-MS performance; using this method, extraction, instrument analysis and data interpretation for 100 samples could be accomplished within a one to two week time period. Results indicated contamination in the blood (∑PCB = 1.9-13 ng g(-1) ww), liver (∑PCB = 0.8-11 ng g(-1) ww), breast (∑PCB = <0.1-9 ng g(-1) ww) and heart tissue (∑PCB = <0.1-6 ng g(-1) ww). Quality control included the analysis of blank samples, NIST SRM 1589a and a duplicate of each sample type (blood or tissue). All blank samples were below the method detection limit, SRM values were within 70% of their certified values and duplicates were within 70% of each other. Correlations were examined for the suite of analysed congeners between blood and various tissues; within select individuals a strong and significant correlation was observed. TEQs were calculated and compared against known toxicity data for bird species. Based on the PCB levels found in this study, no adverse health effects are expected in the birds themselves. ∑PCB concentrations in the breast tissue were also compared against both the Canadian and American guidelines for the consumption of edible poultry and based on these values, the Mallards used in this research would be safe for human consumption.

Chemical and bioanalytical characterization of dioxins in indoor dust in Hong Kong

In the present work, air-conditioner filter dust samples collected from commercial office, secondary school, shopping mall, electronic factory and manufacturing plant in Hong Kong were collected for 7-ethoxyresorufin O-deethylase (EROD) assay using a hepatoma cell line (H4IIE) and chemical analysis of dioxins including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and PCBs with dioxin-like structure. The result of EROD assay showed that bioassay derived TEQ of 2,3,7,8-TCDD (TEQ(bio)) of dust samples varied from 320 to 730 pg/g. Chemical analyses revealed that chemical derived TEQ of 2,3,7,8-TCDD (TEQ(cal)) of dust samples ranged from 134 to 531 pg/g. In addition, the TEQ(cal) of samples were significantly correlated with TEQ(bio) of samples (R=0.83, P<0.01). The average daily doses (ADDs) of dioxins via indoor dust with the estimated ADDs of dioxins via air and food were compared. The results showed that indoor dust is an important medium of exposure to dioxins.

Modifications of commercial pressurized solvent extraction (PSE) systems for the analysis of polychlorinated biphenyls in avian whole blood and serum

The present study considers simple and cost-effective modifications to commercial pressurised solvent extraction cells to extract polychlorinated biphenyls (PCBs) from avian blood and serum. Blood and serum samples of mass 0.2 g were examined. Such masses are consistent with those which may be obtained from many avian species without sacrificing individuals or compromising breeding and (or) migratory success. Extraction vessels are modified by the use of Teflon inserts, which are readily fabricated at low cost. These inserts reduce internal cell volume and surface area. Thus, background contamination is reduced whilst extraction and rinse solvent is used more effectively to afford a small extract volume. Packing of the cell void with sodium sulfate and florisil achieves in situ sample dehydration and lipid removal. When combined with extraction concentration and large volume injection gas chromatography – ion-trap mass spectrometry (LVI-GC–ITMS), the extraction method is capable of polychlorinated biphenyl analysis without post-extraction clean-up. Validation was accomplished using commercial chicken whole blood and serum, and PCB congeners 28, 77, 105, 126, 153, 167, 170, 180, 183, and 194. Surrogate corrected recoveries in the range of 75% to120% for whole blood and 80% to115% for serum were obtained. Detection limits were in the range of 0.01 to 0.22 ng g–1 for whole blood and 0.03 to 0.45 ng g–1 for serum. The relative standard deviations for all congeners investigated were better than 15%.

Rapid quantitative analysis of lipids using a colorimetric method in a microplate format

A colorimetric sulfo-phospho-vanillin (SPV) method was developed for high throughput analysis of total lipids. The developed method uses a reaction mixture that is maintained in a 96-well microplate throughout the entire assay. The new assay provides the following advantages over other methods of lipid measurement: (1) background absorbance can be easily corrected for each well, (2) there is less risk of handling and transferring sulfuric acid contained in reaction mixtures, (3) color develops more consistently providing more accurate measurement of absorbance, and (4) the assay can be used for quantitative measurement of lipids extracted from a wide variety of sources. Unlike other spectrophotometric approaches that use fluorescent dyes, the optimal spectra and reaction conditions for the developed assay do not vary with the sample source. The developed method was used to measure lipids in extracts from four strains of microalgae. No significant difference was found in lipid determination when lipid content was measured using the new method and compared to results obtained using a macro-gravimetric method.