TD-GC-MS raw data measuring NVOC's in UK Forest Air

 A TD-GC-MS study on the NVOC's in forest air. NVOC's are thought to have many beneficial effects on health however very little is known about the composition of air in a UK forest. This study was a preliminary analysis of forest air in a UK ancient woodland.

Methods

A BUCK Elite™ model Elite-1 Personal Air Sampler was used to pump air through Stainless Steel Tenax GR 60/80 Packed thermal desorption (TD) Sample Tubes (Perkin Elmer). The tubes were all pre-conditioned at a temperature of 300oC and a flow rate of 50ml/min helium. The pump was connected to a manifold allowing collection onto 4 tubes simultaneously. The pump was mounted at a height of 1.5m above the forest floor using a camera tripod. The flow rate of sampling was 500ml/min and air was sampled for 2 hours.4 samples were collected in the forest and 4 samples were collected in a control walled garden area. The tubes were removed from the manifold and end capped immediately after sampling. These tubes were then loaded within 24 hours onto a Perkin Elmer Turbo Matrix 650 thermal desorption unit attached to a Perkin Elmer Clarus SQ8T GC-MS system. The temperature ramp for desorption was 40oC/sec up to a final temperature of 290oC with a flow rate of 50ml/min of helium. The tubes underwent a 2-stage desorption of 5 minutes followed by 2 minutes. The samples were injected into the GC-MS onto a Perkin Elmer MS-5 fused silica capillary column (30 x 25um, Perkin Elmer). The initial oven temperature was 50oC and the temperature of the GC oven was ramped at 20oC per minute to a final temperature of 230oC and held there for 10 minutes. Data was acquired over the mass range 50-400amu.