The objective of this project was to develop sampling and analytical methods for hazardous air pollutants, including ethylene thiourea (ETU), catechol, hydroquinone, and 4,4'-methylenedianiline (4,4'-MDA) in stacks and ambient air. All the compounds were sampled using impingers and then analyzed by LC/MS-MS.
Based on experimental results, as for stacks, the detection limits of ETU, catechol, hydroquinone, and 4,4'-MDA were 0.043 ppbv, 0.060 ppbv, 0.138 ppbv, and 0.002 ppbv, respectively. Accuracy were 99.2%, 99.4%, 103% and 105%, respectively. Precision were 5.86%, 6.38%, 3.86%, and 3.64%, respectively.
As for ambient air, the detection limits of ETU, catechol, hydroquinone, and 4,4'-MDA were 0.072 ppbv、0.118 ppbv、0.161 ppbv, respectively. Accuracy were 98.4%, 99.4%, 102%, and 101%, respectively. Precision were 7.84%, 7.88%, 5.68%, and 5.09%, respectively.
The sampling and analytical methods developed in this project were proven to be practical by surveying at least 4 field samplings (air emission stacks or ambient air). Besides, two technical communication seminars were taken place in July and November. All the study results were reported in the technical drafts for EPA’s reference.
