Features of RSpak DE Series

RSpak DE-413 is a polymer-based column for reversed phase chromatography and has unique separation characteristics and superior chemical stability. The column can be used under the same conditions as those for ODS columns. Here, lactitol and erythritol were separated by DE-413, though they could not be separated by a ODS column from other manufacturer. The polarity of the packing material of DE-413 is close to that of ODS columns, however, the separation characteristics of DE-413 is a little different from that of ODS columns and some substances which cannot be separated by ODS columns can be separated by DE-413.

Sample : 0.2% each, 5micro-L
1. Lactitol, 2. meso-Erythritol

Columns      : (Left); Shodex RSpak DE-413 (4.6mmID*150mm), (Right); ODS column
Eluent       : 10mM H3PO4 aq.
Flow rate    : 1.0mL/min
Detector     : Shodex RI
Column temp. : 50deg-C

Since hinokititol and oxin-Cu are strong metal coordination compounds, they are adsorbed with the impurity metals in silica gel and the adsorption causes peak tailing. In case of RSpak DE series (polymer-based columns for reversed phase chromatography), the column is free from the effect of metals and sample will not be adsorbed by the column.

Column       : Shodex RSpak DE-413 (4.6mmID*150mm)
Eluent       : (Left); (1mM EDTA + 20mM KH2PO4) aq./CH3CN=60/40
               (Right); 20mM H3PO4 aq./CH3CN=95/5
Flow rate    : 1.0mL/min
Detector     : UV(254nm)
Column temp. : 40deg-C

RSpak DE series is stable in wide eluent pH range.

Column       : Shodex RSpak DE-413 (4.6mmID*150mm) 
Eluent       : 10mM Sodium phosphate buffer/CH3CN=82/18
Flow rate    : 0.6mL/min 
Detector     : UV(254nm) 
Column temp. : 40deg-C

The production of packing materials for RSpak DE-413 is done in single stage, and, that of ODS columns is done in two stages, production of base material and bonding of C18 group. The simple production process of DE series ensures good reproducibility between production lots.

Sample : 5micro-L
1. 0.2% Methylethyl ketone
2. 0.2% Diethyl ketone
3. 0.4% Di-n-propyl ketone
4. 0.6% Di-n-butyl ketone

Column       : Shodex RSpak DE-413 (4.6mmID*150mm)
Eluent       : CH3CN/H2O=50/50
Flow rate    : 1.0mL/min
Detector     : UV(262nm)
Column temp. : 40deg-C

To realize the best performance of RSpak DE-413 column, we recommend to use the following HPLC system with the column.

Device Recommended specifications and/or setting Example
Pump Flow rate: max. 1mL/min.
Injector Low dead volume type
Sample loop: max. 50micro-microL(5micro-L loop is recommended)
From injector
to column		 0.1 to 0.13mmID, 100mm length piping
From column
to detector		 0.1mmID piping
Detector Detector with a micro cell should be used.
Response should be set to “FAST”.		 Shodex RI-104
(small cell volume)

Sample : (A); 1.5micro-L, (B); 5micro-L
1. Methylethyl ketone 0.2%
2. Diethyl ketone 0.2%
3. Di-n-propyl ketone 0.4%
4. Di-n-butyl ketone 0.6%

Column       : Shodex RSpak DE-413 (4.6mmID*150mm)
Eluent       : CH3CN/H2O=50/50
Flow rate    : 1.0mL/min
Detector     : UV(262nm)
Column temp. : 40deg-C

When di-n-butyl ketone is analyzed using RSpak DE-413 and DE-413L with water/acetonitrile eluent, a decease of theoretical plate number was observed according to an increase of flow rate. The decrease was marked when the flow rate was faster than 1mL/min.

Sample :
(Right); Di-n-butyl ketone
(Center, Left);
1. 0.1% Methylethyl ketone
2. 0.1% Diethyl ketone
3. 0.2% Di-n-propyl ketone
4. 0.3% Di-n-butyl ketone

Columns      : Shodex RSpak DE-413 (4.6mmID*150mm), DE-413L (4.6mmID*250mm)
Eluent       : CH3CN/H2O=50/50
Detector     : UV(262nm)
Column temp. : 40deg-C

Di-n-butyl ketone were analyzed using RSpak DE-413 (a column for reversed phase chromatography). When the sample concentration was constant, a decrease of column efficiency was observed accroding to an icrease of injection volume. The decrease started from 50micro-L and it was marked when the injection volume exceeded 100micro-L. To the contrary, when the injection volume was constant, a decrease of column efficiency was not observed until sample load exceeded 500micro-g.

Column       : Shodex RSpak DE-413 (4.6mmID*150mm)
Eluent       : CH3CN/H2O=50/50
Flow rate    : 1.0mL/min
Detector     : UV(262nm)
Column temp. : 40deg-C