The major objective of this project is to develop sampling and analysis methods of acrylic acid (AA), ethyl acetate (EA), and methyl acrylate (MA) in ambient air and stack and formic acid (HCOOH) and acetic acid (AcOH) in stack.
We have developed a sampling method for the determination of AA in air and AA, HCOOH, and AcOH in stack by serially connecting impinger and sampling pump. Ion chromatography using KOH as eluent solution was employed for the analysis of acrylate, formate and acetate ion absorbed in the deionized water (DIW). The method detection limit (MDL) of AA was 2.3 ppbv in air and 0.009 ppmv in stack, respectively. The MDL of HCOOH and AcOH were 0.016 and 0.011 ppmv in stack, respectively. Besides, EA and MA in air samples were taken in canisters and analyzed by GC/MS. The MDL were 0.074 ppbv for EA and 0.11 ppbv for MA, respectively. EA and MA in stack samples were collected in sampling bags and analyzed by GC/FID. The MDL were 0.11 ppmv for EA and 0.12 ppmv for MA, respectively.
This project is also to measure the concentrations of these compounds in ambient air and stack at the plastics industry, petrochemical industry, waste incinerator, and dyeing and finishing plant by using the above sampling and analytical methods developed. We have carried out 6 sessions of field tests for these compounds sampling.
AA in ambient air and AA, HCOOH and AcOH in stack were measured by the impinger method. The concentration of AA in ambient air was N.D. (<2.3 ppbv) and the recovery was 100.4 to 106.9%. The concentrations of HCOOH, AcOH and AA in stack were N.D. (< 0.016) to 0.084 ppmv, N.D. (<0.011 ppmv), N.D. (<0.009 ppmv), respectively. The recovery were 92.9 to 99.0%, 90.3 to 101.4%, and 90.4%, respectively.
The concentration of EA in air was N.D. (<0.074 ppbv) to 1.41 ppbv and the recovery were 94.3-96.7%. The concentration of MA in air were all N.D. (<0.11 ppbv) and the recovery was 96.4-101.9%. The concentration of EA in stack was N.D. (<0.11 ppmv) and that of MA in stack was N.D. (<0.12 ppmv) to 136.8 ppmv. These results indicates that measurement methods of these compounds in ambient air and stack developed in this study were feasible.
The samples absorbed in water were refrigerated at 4℃ at the lab and need to be analyzed within 14 days of receipt. The samples collected in canisters were stored at ambient conditions and also need to be analyzed within 14 days of receipt. However, the samples collected in bags were stored at ambient conditions and need to be analyzed within 24 h of receipt.
Ｗe have written the 4 drafts of the measurement of these compounds in ambient air and stack to the reference for EPA. In addition, two sessions of technology demonstration workshop were held in September and October, 2021.