Influence of Instruments for Performance of Semi-micro Columns

The chromatograms show the cell volume of UV and RI detectors affected the performance of the separetion. We set the cell volume of the detectors smaller for down sized chromatography. When the UV detector whose cell volume is 2.4 micro-L is used for the analysis, the plate number is ca. 10,000 higher than when the UV detector whose cell volume is 17.7 micro-L is used. (Fig.1)
We can say the same thing regarding RI detector. The cell volume of RI detector affects the plate number of the peaks. The plate number when RI-101 detector is used is a half of that when RI-104 designed for down sized chromatography is used. (Fig.2)
* When the detector for down sized chromatography is used, it is needed to prepeare the instruments including the columns and the injector designed for the down sized chromatography to get good performance.


Sample :
1. PS, Polystyrene (MW: 66,000)
2. PS, Polystyrene (MW: 3,250)
3. PS, Polystyrene (MW: 580)
4. Propylbenzene
5. Benzene

               (Fig.1)               (Fig.2)                 
Columns      : Shodex GPC KF-402HQ   Shodex GPC KF-402HQ (4.6mmID*250mm) x 2
Eluent       : THF                   THF               
Flow rate    : 0.3mL/min             0.3mL/min
Column temp. : 40°C               25°C