Injector with minimal flow-interrupt transient

An injector comprising:

• stator and rotor elements which can rotate relative to one another angularly about an axis of rotation between predetermined load and inject positions, and which have adjacent interface surfaces;
• a first of said elements having a pump port for receiving a mobile phase fluid high pressure, a column port for delivering fluid to a chromatography column, first and second sample ports for connection to opposite ends of a sample loop, and a vent port for venting fluid, each port having at least one opening at the interface between the elements;
• a second of said elements having a sample-receive port for receiving a sample fluid, said second element also having first and second largely circumferentially-extending channels in its face;
• said openings positioned with the opening of said second-sample port lying angularly between a pump opening and the opening at said vent port, and said second channel positioned so in said load position said second channel extends between said second-sample and vent openings, and in said inject position said second channel extends between said second-sample opening and a pump opening;
• said column opening lying angularly between a pump opening and said first-sample opening, and in the load position said first channel extends between a pump opening and said column opening, and in the inject position said first channel extends between said column opening and first-sample opening;
• said pump port has two angularly-spaced pump openings at the interface surface of said first element, including a first pump opening positioned so it opens to said first channel and is connected therethrough to said column opening in the load position, but does not open to either channel in the inject position, and a second pump opening positioned so it opens to said second channel and is connected therethrough to said second-sample opening in the inject position.

An injector comprising:

• stator and rotor elements which can rotate relative to one another angularly about an axis of rotation between predetermined load and inject positions, and which have adjacent interface surfaces;
• a first of said elements having a pump port for receiving a mobile phase fluid under high pressure, a column port for delivering fluid to a chromatography column, first and second sample ports for connection to opposite ends of a sample loop, and a vent port for venting fluid, each port having at least one opening at the interface between the elements;
• a second of said elements having a sample-receive port for receiving a sample fluid, said second element also having first and second largely circumferentially-extending channels in its face;
• said openings positioned with the opening of said second-sample port lying angularly between a pump opening and the opening at said vent port, and said second channel positioned so in said load position said second channel extends between said second-sample and vent openings, and in said inject position said second channel extends between said second-sample opening and a pump opening;
• said column opening lying angularly between a pump opening and said first-sample opening, and said first channel is positioned so in the load position said first channel extends between a pump opening and said column opening, and in the inject position said first channel extends between said column opening and first-sample opening;
• said channels each have leading and trailing edges, said channels are positioned so that at a predetermined transition position between the load and inject positions, the trailing edge of said first channel and the leading edge of said second channel are each partially connected to the pump port.

A method for using an injection device having stator and rotor elements that lie adjacent at an interface, to transfer a sample fluid from a container to an analyzing apparatus such a chromatographic column at high pressure, comprising:

• placing said rotor element in a load position and loading said device, including pumping said sample fluid at low pressure from said container through a port of a first of said elements to an interface between said elements, through a first-sample port of a second of said elements, through a sample loop, through a second-sample port of said second element to said interface, and through a second channel in said second element;
• said step of loading also includes pumping a solvent fluid from a high pressure pump through a pump port of said second element to said interface, through a first channel in said first element and from said first channel to a column port of said first element that is connected to an analyzing apparatus;
• turning said rotor element to an inject position and at said inject position pumping said solvent at high pressure from said pump port, through said second channel, through said second-sample port and said loop to said first sample port, and through said first channel to said column port, to said analyzing apparatus;
• said pump port has two spaced pump openings at said interface, and said step of turning includes disconnecting a first of said pump openings from said first channel and connecting said second channel to a second of said pump openings, all within 10.degree. of rotation of said rotor.