Controlling interdetector band broadening
Methods and apparatus for controlling interdetector band broadening during the analysis of a sample injected into a chromatography system. A column flow is diluted with a dilution flow after the sample exits the chromatography system, and the diluted sample is analyzed by one or a combination of analysis instruments such as a light scattering detector, refractive index detector, an ultraviolet absorption detector.
1. A method to minimize interdetector band broadening and narrow peak breadth of a chromatographic elution of a sample, the method consisting essentially of the steps of
A. providing a column flow;
B. providing a dilution flow;
C. introducing an unfractionated sample into said column flow;
D. passing said column flow borne unfractionated sample through a fractionation means, causing thereby a fractionated sample to elute from said fractionation means;
E. mixing said column flow eluting from said fractionation means with said dilution flow, creating, thereby, a diluted, fractionated sample;
F. passing, by interconnecting, tubing said diluted, fractionated sample to one or more analysis instruments connected in series by tubing; and
G. analyzing said diluted, fractionated sample with said one or more analysis instruments.
2. The method of claim 1 , wherein said column flow comprises a first solvent.
3. The method of claim 2 , wherein said dilution flow comprises a second solvent.
4. The method of claim 3 , wherein said first solvent and said second solvent are the same.
5. The method of claim 3 , wherein said first solvent and said second solvent are different.
6. The method of claim 1 , wherein said at least one analysis instrument comprises an instrument selected from the group consisting of a light scattering detector, a refractive index detector, an ultraviolet absorption detector, and combinations thereof.
7. The method of claim 1 , wherein said fractionation means is configured to perform high performance liquid chromatography.
8. The method of claim 1 , wherein said fractionation means performs chromatography techniques selected from the group consisting of ion exchange chromatography, size exclusion chromatography, affinity chromatography, gas-liquid chromatography, gas chromatography, and combinations thereof.
9. The method of claim 1 , wherein said column flow is diluted by said dilution flow in a ratio ranging from 1:1 (1 part column flow to 1 part dilution flow 1) to 1:10 (1 part column flow to 10 parts dilution flow 1).
10. The method of claim 1 further comprising the step of filtering said diluted, fractionated sample prior to analysis by said one or more analysis instruments.
11. The method of claim 1 further comprising the step of filtering said unfractionated sample bearing column flow prior to said passage through said separation means.
12. The method of claim 1 further comprising the step of filtering said dilution flow prior to mixing with said column flow.
13. The method of claim 1 wherein said column flow and said dilution flow are mixed at a T-union.
14. The method of claim 13 wherein said mixing is continued in a downstream filter prior to analysis by said one or more analysis instruments.