Considering size-exclusion chromatography, ion-exchange chromatography, reversed-phase liquid chromatography, and capillary electrophoresis list the possible combinations (there are a total of 6) of techniques that could be coupled to give a 2-dimensional separation.
a. which technique of the two would be best suited as the 1st dimension
b. the orthogonality of the two techniques
c. the comprehensiveness of the combination
a. which technique of the two would be best suited as the 1st dimension
b. the orthogonality of the two techniques
c. the comprehensiveness of the combination
To determine the possible combinations of techniques that can be coupled to give a 2-dimensional separation, we need to consider the characteristics and principles of each technique.
a. The choice of the technique for the first dimension depends on the sample complexity and the desired separation mechanism. In general, size-exclusion chromatography (SEC) or ion-exchange chromatography (IEC) are well-suited as the first dimension, as they can effectively separate molecules based on size or charge.
b. Orthogonality refers to the degree of complementarity between the two techniques, where they separate molecules differently. The higher the orthogonality, the greater the chance of achieving better separation. In this case, SEC and IEC are considered more orthogonal to the other two techniques (reversed-phase liquid chromatography (RPLC) and capillary electrophoresis (CE)).
c. Comprehensiveness refers to the overall separation power of the combination, considering both orthogonality and resolution. The most comprehensive combinations would involve using SEC or IEC as the first dimension and RPLC or CE as the second dimension since these pairs have more orthogonal separation mechanisms.
Considering these factors, the possible combinations of the techniques are as follows:
1. SEC (1st dimension) -> RPLC (2nd dimension)
2. SEC (1st dimension) -> CE (2nd dimension)
3. IEC (1st dimension) -> RPLC (2nd dimension)
4. IEC (1st dimension) -> CE (2nd dimension)
5. RPLC (1st dimension) -> SEC (2nd dimension)
6. CE (1st dimension) -> SEC (2nd dimension)
These combinations offer different levels of orthogonality and comprehensiveness, and the choice between them depends on the specific requirements of the separation.