Diaphragm-sealed valve, analytical chromatographic system and method using the same

A diaphragm-sealed valve comprising:

• a first body having a first interface provided with a plurality of distinct recessed fluid communication channels extending therein, said first body having a plurality of port sets, each comprising a first, a second and a common fluid port, each port of a corresponding set opening into a corresponding one of said recessed fluid communication channels respectively for interconnecting each port of said corresponding set together through said corresponding fluid communication channel respectively, each of said first and second ports of each of said sets being provided with a seat disposed so as to allow fluid communication therearound within said corresponding communication channel;
• a second body interconnected with said first body and having a second interface facing said first interface, said second body having a plurality of passage pairs, each comprising a first and a second passage, each passage of a corresponding pair respectively facing one of said first and second ports of a corresponding set;
• a seal member compressibly positioned between said first and second interfaces, said seal member having a shape adapted to cover each of said first and second ports of all of said port sets;
• a plurality of pairs of first and second plungers, each plunger of a corresponding pair being respectively slidably disposed in one of said passages of a corresponding pair, each of said plungers having a closed position wherein the corresponding plunger presses down the seal member against the seat of the corresponding port for closing said corresponding port, and an open position wherein said plunger extends away from the seat of the corresponding port for allowing a fluid communication between the corresponding port and a corresponding channel;
• and
• actuating means for actuating each of said plungers between said closed and open positions thereof.

An analytical chromatic method comprising the steps of:

• a) providing a fluid sampling system comprising a diaphragm-sealed valve provided with a plurality of independently actuated ports serially interconnected to each other, said fluid sampling system further comprising a sample inlet, a carrier inlet, a sampling loop having an inlet and an outlet, a sample vent line and analytical means provided with an inlet, each being operatively interconnected to said valve through a corresponding one of said ports;
• b) providing fluid communication from said sample inlet to the inlet of the sampling loop by actuating the corresponding ports, thereby providing a fluid sample in said sampling loop;
• c) closing the outlet of said sampling loop by actuating the corresponding port to isolate said sampling loop;
• d) providing fluid communication from the carrier inlet to the inlet of the sampling loop by actuating the corresponding port to pressurize said sampling loop;
• e) preventing fluid communication from each of said ports to the remaining ports by actuating the corresponding ports;
• and
• f) providing fluid communication from the outlet of the sampling loop to the inlet of the analytical means by actuating the corresponding port, thereby injecting said sample in said analytical means.