This report describes the integration of a portable Gas Chromatograph-Mass Spectrometer (GCMS) with a Membrane Interface Probe (MIP) site survey system in order to provide on-site qualitative and quantitative Volatile Organic Compound (VOC) data at the SABRE research cell in Derbyshire. The first part of the report gives an introduction to both technologies and a background to the site conditions. Methodologies and limitations are discussed. The second part of the report discusses and compares the results obtained from the MIP pushes, GC-MS analysis of the gas stream and soil samples collected from boreholes drilled adjacent to the MIP wells. An attempt is made to calibrate the MIP voltage responses using data from the GC-MS, results are presented both in the text and in the appendices. A comparison of on-site and off-site soil analysis data is made, highlighting the potential for loss of volatiles when samples are sent away for analysis. Soil data is also compared to the on-site down hole gas data.