Process sampling module coupled with purge and trap-GC-FID for in situ auto-monitoring of volatile organic compounds in wastewater.
An automatic sampling device, i.e., process sampling module (PSM), connected with a purge and trap-GC-FID system has been developed for real-time monitoring of VOCs in wastewater. The system was designed to simultaneously monitor 17 compounds, including one polar compound, i.e., acetone, and 16 non-polar compounds. The trapping tube is packed with two adsorbents, Carbopack B and Carbosieve III, to trap target compounds. For the purpose of in situ monitoring, the flush valve of the sampling tube is composed of two two-way valves and a time controller to prevent absorption interference of the residue. The optimal conditions for the analytical system include a 12 min purge time at a temperature of 60 degrees C, and 4 min of desorption time with a desorption temperature of 260 degrees C. Good chromatograms have been obtained with the analytical system even if a cryogenic device and de-misting were not used. The relative standards deviation (RSD) of the system is between 2% and 13.4%, and accuracies between 0.3 and 23.5% have been achieved. The detection limits of the method range from 0.32 to 2.39 ppb. In this system, the four parts, i.e., PSM, P&T, GC, and FID, were simple, reliable and rugged. Also, the interface of these four parts was simple and dependable.
Liu
Hsin-Wang
HW
Department of Biomedical Engineering and Environmental Science, National Tsing-Hua University, Hsinchu, Taiwan, ROC.
Liu
Yung-Tsun
YT
Wu
Bei-Zen
BZ
Nian
Hung-Chi
HC
Chen
Hsing-Jung
HJ
Chiu
Kong-Hwa
KH
Lo
Jiunn-Guang
JG
D000096:Acetone / Q000032:analysis; D000327:Adsorption; D002725:Chloroform / Q000032:analysis; D002849:Chromatography, Gas / Q000295:instrumentation / Q000379:methods*; D004784:Environmental Monitoring / Q000379:methods*; D015203:Reproducibility of Results; D014050:Toluene / Q000032:analysis; D055549:Volatile Organic Compounds / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
D055549:Volatile Organic Compounds; D014874:Water Pollutants, Chemical; D000096:Acetone; D014050:Toluene; D002725:Chloroform