Two valves switching modulator for comprehensive two-dimensional gas chromatography

Abstract

The present invention is an improvement to two-dimensional comprehensive gas chromatography. The improvement is a two-valve switching modulator connecting two different type of separation columns. The advantages of current invention are (1) a simple system can be built by readily available parts; (2) no specific materials required (other than electricity) to operate the system, especially, do not need any type of coolant; (3) can be build on any GC as an externally added on unit; (4) The first and the second dimensional column flow are independently controlled, it is easier to design the experiment; and (5) it is cost effective, the cost of building this system is inexpensive than other type of modulation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic diagram of the valve modulation system of the present invention.

FIG. 2 shows a schematic diagram showing the flow of the fluid from the first column through the valve modulation system into the second column.

FIG. 3 shows a comprehensive two-dimensional gas chromatogram of naphtha using the valve modulation system of the present invention.

FIG. 4 shows a comprehensive two-dimensional gas chromatogram of diesel using the valve modulation system of the present invention.

FIG. 5 shows a schematic diagram of an alternative arrangement of the comprehensive two-dimensional gas chromatography switching valve modulation system of the present invention.

FIG. 6 shows a schematic diagram of valve modulation system including only one valve.

Claims

1. In a two-dimensional comprehensive Gas Chromatography system (GC×GC), the improvement which comprises a two valve switching modulator.

2. The GC×GC of claim 1 wherein the two valve switching modulator maintains a carrier gas through both chromatographs.

3. The GC×GC of claim 2 wherein said carrier gas is helium, or hydrogen or nitrogen or other inert (non-reactive gas).

4. The GC×GC of claim 3 wherein said modulator includes two valves and two transfer lines.

5. The GC×GC of claim 4 wherein said carrier gas is switched between said transfer lines.

6. The GC×GC of claim 5 wherein said modulator that connects the first dimensional column, the second dimensional column, the second dimensional column flow, and the vent can have more than one type of valve.

7. The GC×GC of claim 6 wherein said the second dimensional column flow can be independently controlled.

8. The GC×GC of claim 7 wherein said the second dimensional column temperature can be independently controlled.

9. The GC×GC of claim 8 wherein said modulator switching system can be accomplished by only one valve.