New antibody and immunoassay pretreatment strategy to screen polychlorinated biphenyls in Korean transformer oil.

Development and modifications are described that expand the application of an immunoassay from the detection of Kanechlors (Japanese technical PCBs mixtures) to the detection of Aroclors (U. S. technical PCB mixtures, used in Korea) in contaminated Korean transformer oil. The first necessary modification was the development of a new antibody with a reactivity profile favorable for Aroclors. The second modification was the addition of a second column to the solid-phase extraction method to reduce assay interference caused by the Korean oil matrix. The matrix interference is suspected to be caused by the presence of synthetic oils (or similar materials) present as contaminants. The modified assay was validated by comparison to high-resolution gas chromatography/high-resolution mass spectrometry analysis, and was shown to be tolerant of up to 10% of several common synthetic insulating oils. Finally the screening performance of the modified assay was evaluated using 500 used transformer oil samples of Korean origin, and was shown to have good performance in terms of false positive and false negative rates. This report provides evidence for the first establishment of immunoassay screening for Aroclor based PCB contamination in Korean transformer oil.

Polychlorinated biphenyl congeners in river sediments: distribution and source identification using multivariate factor analysis.

To assess the level of polychlorinated biphenyl (PCB) contamination and identify their sources, surface sediments were collected from selected locations along Nakdong River, Korea, and analyzed for 209 PCB congeners using high-resolution gas chromatography/high-resolution mass spectroscopy. PCB levels ranged from 0.124 to 79.2 ng/g dry weight (coplanar PCBs 0.295 to 5720 pg/g dry), which were similar to those of three other major rivers (Han, Geum, and Youngsan rivers) in Korea but slightly lower than those in neighboring countries. Regarding homologue composition, tetra-CBs were most abundant in most samples, but some samples with much higher PCBs concentrations had relatively lower proportions of tetra-CBs and higher proportions of penta- to hepta-CBs. To identify the sources of PCBs in sediment samples, principal component analysis/absolute principal component scores (PCA/APCS), positive matrix factorization (PMF), and multiple linear regression (MLR) were used with the congener composition of aroclors (1242, 1248, 1254, and 1260) and the flue gas of waste incinerators (data obtained from a previous article) as source profiles. Results showed that the three models showed similar source apportionments. Most sediment samples with lower PCB concentrations had higher proportions of incineration-derived materials, and some sediment samples with much higher PCB concentrations had higher proportions of aroclor 1260. This occurred because many industrial facilities, such as landfill leachate-treatment facilities, were gathered around sampling points with high PCB concentrations, and high-chlorinated PCBs are more stable in the elution process of landfill leachate than the incineration process. PCB concentrations estimated by APCS, PMF, and MLR were similar to the measured values with coefficients of determination ranging from 0.77 to 0.99.

Source identification of atmospheric polycyclic aromatic hydrocarbons in industrial complex using diagnostic ratios and multivariate factor analysis.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants worldwide; currently, they are being described as potential persistent organic pollutants (POPs). This study is aimed to identify sources of PAHs in the atmosphere around the Sihwa and Banwol industrial area by using diagnostic ratios and multivariate factor analysis such as principal component analysis/absolute principal component score (PCA/APCS) and positive matrix factorization (PMF). The atmospheric PAHs level was 8.07-177 ng/m(3) (gaseous phase: 5.93-68.4 ng/m(3); particulate phase: 1.85-128 ng/m(3)) and PAHs concentration in the warm period was lower than the cold period. As a result of the examination of relative BaP concentration, photodecomposition was found not to be an important factor in the seasonal difference of PAHs concentration in this study. Source identification was first carried out through a double ratio plot. As a result of double ratio plots, atmospheric PAHs in this study were found to stem from the combination of vehicular emission, combustion (coal or biomass-wood or grass), and petroleum. Moreover, PCA/APCS and PMF showed that the main sources were vehicular emission and coal combustion and and incineration-related source with a summed contribution of about 72.6-86.7%. Finally, the fitness of the two models was very good; the estimated values were highly correlated with the measured values (R(2) = 0.991-0.999, p < 0.05).