Competitive immunoassay for monitoring polybrominated diphenyl ethers in PM2.5 in Shanghai

In this paper, a sensitive biotin–streptavidin (BS)-ELISA was developed for determining the polybrominated diphenyl ethers in PM_2.5. For establishing this proposed BS-ELISA, we prepared the biotinylated antibody primarily. And for reducing the background interference, some in?uencing factors and procedures for this immunoassay were also discussed and optimised. Under the optimal conditions, the IC₅₀ = 0.53 ng/mL; IC₁₀ was 0.002 ng/mL; and the results were almost consistent with those using the gas chromatography and electron capture detection (GC-ECD). Less procedures and simpler sample preparation were required for this method compared with the GC-ECD. The results showed that the highest value of BDE-47 concentration occurred in December, which might re?ect the combination of heating and industrial pollution. In our analysis, we studied the Pearson correlations between BDE-47/PM_2.5 and gaseous pollutants (such as NO₂, SO₂, CO, O₃, PM₁₀ and PM_2.5). BDE-47 showed a higher correlation with NO₂ than that with PM₁₀, PM_2.5 and SO₂, which implied that the BDE-47 emission process might be accompanied by the emission of NO₂. Moreover, during the Spring Festival, the concentration of BDE-47 in PM_2.5 decreased significantly, whereas the PM_2.5 changed little. This suggested factories and vehicles might be the major contributors to BDE-47 emissions (but not to PM_2.5).