Characterising volatile organic compounds from sewer emissions by thermal desorption coupled with gas-chromatography-mass spectrometry

An analytical method was developed to characterise volatile organic compounds (VOCs) emitted from sewer networks by actively collecting the samples using sorbent tubes followed by the Thermal Desorber coupled with Gas Chromatography-Mass Spectrometry (TD-GC-MS). The method parameters including sorbent tubes materials, tube desorption temperature, desorption time and cold trap desorption temperature were selected and optimized. Validation of TD-GC-MS method showed good precision, linearity and accuracy. Breakthrough tests showed that there is no significant breakthrough when 5,000 ppm (v/v) stock solution was spiked into sorbent tubes (breakthrough volume<1 %). The method was evaluated by collecting VOCs from two sewer sites in Sydney. The identification of key chemical groups at individual site is important for monitoring odour annoyance and developing design criteria for odour and VOC abatement systems.