A liquid separation apparatus for removing a liquid from a respiratory gas is disclosed herein. The liquid separation apparatus includes a housing (10) having an input (15) for delivering a sample withdrawn from the respiratory gas and a first output (18) for discharging at least part of the sample of the respiratory gas and a first filter (24) with a hydrophobic property for removing the liquid from the gas sample flowing through the input and first output of the housing. The first filter (24) also having an oleophobic property to improve a removal of the liquid in case a surface tension of the liquid is lower than a surface tension of bodily fluids. Also a respiratory gas analyzing system including the liquid separation apparatus is disclosed.
