英文摘要 |
The objective of this project was to develop sampling and analytical methods for volatile organic compounds, including chloroprene, benzotrichloride, 1,2-dichloropropane, vinyl acetate, bromomethane, chloromethane, allyl chloride, 1,1-dichloroethene, and methyl methacrylate in stacks and ambient air. As for stacks, chloroprene, 1,2-dichloropropane, bromomethane, chloromethane, allyl chloride, and 1,1-dichloroethene were sampled using gas sampling bags and then analyzed by GC/ECD; vinyl acetate, and methyl methacrylate were sampled using gas sampling bags and then analyzed by GC/FID; benzotrichloride were sampled using absorption solvent and then analyzed by GC/MS. As for ambient air, all the target compounds were sampled using canisters and then analyzed by GC/MS.
Based on experimental results, as for stacks, the detection limits of chloroprene, benzotrichloride, 1,2-dichloropropane, vinyl acetate, bromomethane, chloromethane, allyl chloride, 1,1-dichloroethene, and methyl methacrylate were 0.037 ppmv,4.798×10-3 ppmv, 0.036 ppmv, 0.210 ppmv, 0.031 ppmv, 0.034 ppmv, 0.038 ppmv, 0.035 ppmv, and 0.189 ppmv, respectively. Accuracy were 103.14%, 97.71%, 107.21%, 98.46%, 105.98%, 103.59%, 101.73%, 106.16%, and 98.23%, respectively. Precision were 5.37%, 6.73%, 6.95%, 2.03%, 4.65%, 6.81%, 5.10%, 5.50%, and 2.27%, respectively.
As for ambient air, the detection limits of chloroprene, benzotrichloride, 1,2-dichloropropane, vinyl acetate, bromomethane, chloromethane, allyl chloride, 1,1-dichloroethene, and methyl methacrylate were 0.388 ppbv (full scan) and 0.143 ppbv (SIM mode), 0.467 ppbv (full scan) and 0.188 ppbv (SIM mode), 0.183 ppbv (SIM mode), 0.716 ppbv (SIM mode), 0.173 ppbv (SIM mode), 0.179 ppbv (SIM mode), 0.164 ppbv (SIM mode), 0.139 ppbv (SIM mode), and 0.185 ppbv (SIM mode), respectively. Accuracy of chloroprene were 91.13% (full scan) and 101.98% (SIM mode); and precision were 6.61% (full scan) and 7.92% (SIM mode). Accuracy of benzotrichloride were 106.78% (full scan) and 105.31% (SIM mode); and precision were 6.85% (full scan) and 7.47% (SIM mode).
The sampling and analytical methods developed in this project were proven to be practical by surveying at least 4 field samplings (stacks or ambient air). Besides, two technical communication seminars were taken place in July and October. All the study results were reported in the technical drafts for EPA’s reference.
|