Membrane countercurrent exchanger and membrane inlet mass spectrometer for the analysis of gas partial pressure in liquid samples

A countercurrent membrane exchanger which equilibrates a carrier fluid with a sample of a liquid containing a dissolved gas therein, comprising:

• a membrane;
• and
• first and second plates each having an inlet port and an outlet port and a groove formed therein so as to form a channel between said inlet port and said outlet port, said first and second plates being disposed on opposed sides of said membrane so that the grooves of said first and second plates are complementary to each other and the groove of each plate is exposed to opposed sides of said membrane, whereby when said liquid is passed through the channel of said first plate and said carrier fluid is passed through the channel of said second plate so as to flow in an opposite direction of said liquid adjacent said membrane, said gas passes from said liquid through said membrane to said carrier fluid.

A tubular direct insertion membrane probe (t-DIMP) type mass spectrometer which receives a liquid containing a dissolved gas therein via an inlet tube and expels said liquid via an outlet tube and measures said gases, comprising:

• a silicone membrane connected to an inlet side of said inlet tube and an outlet side of said outlet tube;
• and
• an insulating sleeve disposed about the connections between said silicone membrane and said inlet and outlet tubes so as to substantially prevent said gases from leaking out at said connections in a non-uniform manner.