We have demonstrated a highly sensitive trace gas sensor for real-time detection of benzene. With a 90 s sampling cycle, we reach a detection limit of 150 ppt (3σ). Common interferents were found to have little effect on the benzene measurements, but for accurate measurements of low benzene concentrations in the ambient air, it may be necessary to measure humidity of the sample flow and apply a correction to the measured concentration. Compact size and simple design of the measurement setup are ideal for development towards a portable instrument for on-site measurements. The small form factor and a simple measurement principle based on fitting of reference absorption spectra, support the potential of its use also in autonomous monitoring applications. Our results also show great compatibility between CEPAS and enhancement through enrichment. The CEPAS cell requires a sample volume of less than 10 mL and as long as the desorption can be performed efficiently with equally small gas volume, the spectral measurement can be performed from a highly enriched sample.