Patent ID: 8312762
Filing Date: 2012-11-20
Classification: G01N,G05D

Abstract:
1. A device for placing a sample in a chromatography system having a system pressure at which solvent flows, the device comprising: a valve means for selectively placing a sample in a column line comprising a sample port, withdrawing port, first loop port, second loop port, column port and constant flow port; said valve means having a plurality of positions comprising a first position in which said one of said first loop port and said second loop port is in communication with said sample port and the remaining first loop port and second loop port is in communication with said withdrawal port, and said constant port is in communication with said column port, a second position in which at least one of said first loop port and said second loop port is in fluid communication with a pressure source, and a third position in which said first loop port and said second loop port are in fluid communication with said constant flow port and said column port; said valve means in signal communication with control means and assuming said first position upon receiving a first signal command, assuming said second position upon receiving a second signal command and assuming said third position upon receiving a third signal command; a sample introduction line in fluid communication with said sample port and with a source of sample and, upon said valve means assuming a second position, a source of pressure, said sample introduction line for receiving sample and conveying said sample into said valve means and through at least one of said first sample port and second sample port and into a sample loop when said valve means is in said first position and pressurizing said sample in said sample loop upon said valve means assuming said second position; a withdrawal line in fluid communication with said withdrawal port and a source of reduced pressure to withdraw sample through said sample introduction line and into valve means and said sample loop upon said valve means assuming said first position; a sample loop in fluid communication with said first sample port and said second sample port for receiving sample withdrawn through said valve means and holding said sample, and upon said valve means assuming said second position, pressurizing said sample, and upon said valve means assuming a third position, discharging said pressurized sample through said valve means and said column port as said sample loop is placed in communication with said constant flow port and said column port; a column line in fluid communication with said column port for receiving sample from said sample loop and for directing sample to one or more columns; a constant flow port for being placed in communication with a source of the solvent; a withdrawal pump in fluid communication with said withdrawal line and in signal communication with control means, said withdrawal pump depressurizing said withdrawal line to pull sample into said sample introduction line in said first position; a pressure source in fluid communication with at least one of said sample introduction line and said sample loop for placing said sample in said sample loop under pressure; and, a control means in signal communication with said pressure source, said withdrawal pump and said valve means, said control means instructing said valve means to assume said first position in which a sample is received in said sample introduction, said control means issuing said valve means to assume said second position and signaling said pressure source to pressurize said sample loop while said sample is received therein to 70 to 100% of the system pressure to reduce pressure perturbations when said valve means moves to said third position and introduces the pressurized sample to the solvent flowing at the system pressure.