| 英文摘要 |
The objective of this project was to develop sampling and analytical methods for organic air pollutants, including propylene glycol methyl ether (PGME), propylene glycol methyl ether acetate (PGMEA), diethylene glycol butyl ether (BDG), diethylene glycol methyl ether (DPM), 2-butoxyethanol, 2-ethoxyethanol, ethylene glycol monoethyl ether acetate (EGEEA), 2-methoxyethanol, and 2-methoxyethyl acetate (EGMEA) in stacks and ambient air. All the target compounds in stacks or ambient air were sampled using methanol and then analyzed by GC/MS or GC/FID.
In this project, PGME, PGMEA, BDG, 2-butoxyethanol, 2-ethoxyethanol, EGEEA, 2-methoxyethanol, and EGMEA were analyzed using GC/MS with both qualitative and quantitative analyses. DPM (CAS NO. 34590-94-8) is mixture of 4 structural isomers (CAS NO. 13429-07-7, CAS NO. 20324-32-7, CAS NO. 13588-28-8, CAS NO. 55956-21-3). Each isomer has two asymmetrical carbon atoms, and this each isomer has 4 configurational isomers. Therefore, DPM standard products from different sources may have different isomer ratios due to different manufacturing processes, and thus appear different chromatographic peaks. According to OSHA 101, quantification of DPM can be done by summing the peak areas of the isomers using GC/FID, since the response of all the isomers of DPM are identical. All DPM samples in this project were analyzed by GC/FID.
Based on experimental results, as for stacks, the detection limits of PGME, PGMEA, BDG, DPM, 2-butoxyethanol, 2-ethoxyethanol, EGEEA, 2-methoxyethanol, and EGMEA were 0.038 ppmv, 0.027 ppmv, 0.024 ppmv, 0.018 ppmv, 0.018 ppmv, 0.040 ppmv, 0.024 ppmv, 0.054 ppmv and 0.029 ppmv, respectively (sampling volume was 100L, 5 L/min × 20 min, isokinetic sampling). As for ambient air, the detection limits of PGME, PGMEA, BDG, DPM, 2-butoxyethanol, 2-ethoxyethanol, EGEEA, 2-methoxyethanol, and EGMEA were 31.9 ppbv, 21.4 ppbv, 20.1 ppbv, 13.9 ppbv, 15.5 ppbv, 33.5 ppbv, 20.1 ppbv, 47.2 ppbv, and 25.7 ppbv, respectively (sampling volume was 60L, 1 L/min × 60 min, constant flow). The accuracy and precision of PGME (using GC/MS) were 108.112.51% (@5 mg/L), and 96.793.93% (@2 mg/L). The accuracy and precision of PGMEA (using GC/MS) were 103.912.17% (@5 mg/L), and 100.363.14% (@2 mg/L). The accuracy and precision of BDG (using GC/MS) were 99.433.49% (@5 mg/L), and 94.864.13% (@2 mg/L). The accuracy and precision of DPM (using GC/FID) were 99.062.92% (@5 mg/L), and 99.293.00% (@2 mg/L). The accuracy and precision of 2-butoxyethanol (using GC/MS) were 105.802.18% (@5 mg/L), and 96.714.14% (@2 mg/L). The accuracy and precision of 2-ethoxyethanol (using GC/MS) were 99.232.40% (@5 mg/L), and 96.144.08% (@2 mg/L). The accuracy and precision of EGEEA (using GC/MS) were 104.002.52% (@5 mg/L), and 100.793.91% (@2 mg/L). The accuracy and precision of 2-methoxyethanol (using GC/MS) were 109.403.12% (@5 mg/L), and 97.713.20% (@2 mg/L). The accuracy and precision of EGMEA (using GC/MS) were 102.031.97% (@5 mg/L), and 99.432.99% (@2 mg/L).
The sampling and analytical methods developed in this project were proven to be practical by surveying at least 6 field samplings (stacks or ambient air). Besides, two technical communication seminars were taken place in September and October. All the study results were reported in the technical drafts for EPA’s reference.
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