HPLC schematic with integrated sample cleaning system
First Claim
1. An HPLC flow system, comprisinga separation column;
- a detector; and
means connecting the outlet end of the separation column with the detector;
a syringe;
an injector with a sample reservoir;
a sample accumulation loop;
a guard column; and
means connecting the syringe to the accumulation loop, to one end of the guard column, and to the injector, sample reservoir and waste; and
a mobile phase reservoir;
a high pressure pump; and
valve means operable;
in a first operative position to define a first flow schematic serially connecting the injector and sample reservoir, accumulation loop, and syringe, whereby powered syringe intake draws the sample into the accumulation loop; and
in a second operative position to define a second flow schematic serially connecting the pump, accumulation loop, guard column, separation column, detector, and the injector to waste, whereby pump operation advances the mobile phase and sample in one direction serially through these components; and
in the first operative position again to define a third flow schematic, whereby pump operation advances the mobile phase in the same direction through the separation column and detector, while advancing the mobile phase in the reverse direction through the guard column for back flushing it.
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Accused Products
Abstract
The disclosed HPLC flow schematic back-flushes the guard column with mobile phase once every operating cycle, the regular cleaning maintaining its effectiveness and useful life. This mobile phase flow reversal is accomplished by imposing a two position multiple port switching valve between the guard and separation columns. In one valve position, the mobile phase is pumped in one flow direction through both the separation and guard columns, but the switched valve maintains the same flow direction only through the separation column and reverses the mobile phase flow direction through the guard column, for effectively cleaning the guard column. Moreover, the mobile phase back flow is directed over the emptied sample drawing needle for cleaning it to reduce possible sample cross contamination. The improved flow circuits use basically only the typical HPLC system components, except for some insignificant modifications from existing injector designs.
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Citations
12 Claims
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1. An HPLC flow system, comprising
a separation column; - a detector; and
means connecting the outlet end of the separation column with the detector;a syringe;
an injector with a sample reservoir;
a sample accumulation loop;
a guard column; and
means connecting the syringe to the accumulation loop, to one end of the guard column, and to the injector, sample reservoir and waste; anda mobile phase reservoir;
a high pressure pump; and
valve means operable;in a first operative position to define a first flow schematic serially connecting the injector and sample reservoir, accumulation loop, and syringe, whereby powered syringe intake draws the sample into the accumulation loop; and in a second operative position to define a second flow schematic serially connecting the pump, accumulation loop, guard column, separation column, detector, and the injector to waste, whereby pump operation advances the mobile phase and sample in one direction serially through these components; and in the first operative position again to define a third flow schematic, whereby pump operation advances the mobile phase in the same direction through the separation column and detector, while advancing the mobile phase in the reverse direction through the guard column for back flushing it. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
- a detector; and
Specification