Device for extracting volatile species from a liquid

A device for extracting volatile species from an associated liquid and being suitable for connection to an inlet of an associated mass spectrometer, the device comprising:

• a. a chamber, wherein the volume of the chamber is 1 ml or less,
• b. a membrane, which:
• i. connects the inside of the chamber with the outside of the chamber,
• ii. forms a barrier for the liquid at zero, or near-zero, differential pressure between the inside and the outside of the chamber,
• iii. allows passage of the volatile species at zero, or near-zero, differential pressure between the inside and the outside of the chamber,
• c. an inlet capillary channel which connects the inside of the chamber with the outside of the chamber, the inlet capillary channel being arranged for intake of a carrier gas, wherein said inlet capillary channel is adapted to flow carrier gas into the chamber to maintain a chamber pressure near an ambient pressure of the associated liquid, and
• d. an outlet capillary channel which connects the inside of the chamber with the inlet of the mass spectrometer, the outlet capillary channel being arranged for connection with the inlet of the mass spectrometer, wherein the outlet capillary channel comprises a length (L), a width (W) and a height (H), and wherein the outlet capillary channel has a length to width ratio (L/W) or a length to height ratio (L/H) to provide a pressure at the inlet of the mass spectrometer that is lower than the chamber pressure such that a pressure reduction factor between the chamber pressure and the pressure at the inlet of the mass spectrometer is at least 105,
• wherein, upon immersion of the device into the liquid, the device allows the liquid to come into contact with the membrane.