Exhaled breath analysis in health and disease is an area of growing clinical interest with the potential to be adopted through the whole respiratory healthcare continuum. However, currently there is no standard for exhaled breath collection, and the optimal way to preconcentrate the highly humid exhaled breath is not known. Described is an optimized combination of sorbent materials and sample handling methods that allows quantitative capturing of exhaled molecules over a broad range in highly humid conditions. The invention can be applied in pre-concentration units of future devices for exhaled breath analysis, for example at the bedside.