Multiplexing capillary array for atmospheric pressure ionization-mass spectrometry

An apparatus for introducing a sample from a fluid stream into a mass analyzer comprising:

• a first chamber;
• a second chamber having a lower pressure than said first chamber and in fluid communication with said mass analyzer;
• a transfer capillary having two channels, each channel having an inlet located within said first chamber and an outlet located within said second chamber;
• a multiplex selector that allows ions to flow through a selected subset of said two channels and that is capable of changing the set of channels comprising said selected subset, and
• two ionizers in fluid communication with said two fluid streams, wherein said ionizers generate ionized sample within said first chamber and direct said ionized sample into corresponding inlets of said transfer capillary.

A method for introducing two or more samples from two or more fluid streams into a mass analyzer comprising:

• ionizing said two or more samples within a first chamber having a first pressure;
• directing each of said two or more ionized samples toward corresponding inlets of a transfer capillary, wherein said inlets are in fluid communication with inlet channels, said inlet channels are in fluid communication with an outlet channel, said outlet channel is in fluid communication with an outlet and said outlet is located within a second chamber, said second chamber in fluid communication with said mass analyzer and said second chamber having a second pressure, wherein said second pressure is less than said first pressure thereby causing said two or more ionized samples to flow through said inlet channels;
• and
• retarding flow through a selected subset of said inlet channels using a multiplex selector within said transfer capillary such that a subset of said two or more ionized samples are retained within said transfer capillary, and wherein said multiplex selector is capable of changing the set of inlet channels comprising said selected subset.

A method for introducing two or more samples from two or more fluid streams into a mass analyzer comprising:

• ionizing said two or more samples within a first chamber having a first pressure;
• directing each of said two or more ionized samples into corresponding inlets, wherein each of said inlets is in fluid communication with a channel, each of said channels is in fluid communication with an outlet, and each outlet is located within a second chamber, said second chamber in fluid communication with said mass analyzer and said second chamber having a pressure less than said first chamber thereby causing said two or more ionized samples to flow through said channels;
• and
• retarding flow through a selected subset of said channels using a multiplex selector within said transfer capillary such that a subset of said two or more ionized samples are retained within said transfer capillary, and wherein said multiplex selector is capable of changing the set of channels comprising said selected subset.