10.50.3 Sovent Repacement Method for llil) Organc SEC (GPCCoumnsSize exclusion chromatography (SEC) is a chromatography that separates the analytes based on the size of sample (polymer) molecules. The samples are generally prepared in a solvent that dissolves the target polymer well. Therefore, some target polymers may be dissolved in a solvent different from the shipping solution of SEC columns. In such cases, the column solvent needs to be replaced with the solvent to be used.Shodex offers several SEC column series such as Asahipak GF series and OHpak series. Here, the GPC series, organic SEC (GPC) columns, are used as an example to explain the solvent replacement method.Please consider this page as a general guideline and make sure to read the column-specific operation manual before replacing the solvents in your columns. Before Starting: Check ListIncorrect solvent replacement method may damage the column. Please make sure to check the followings before replacing the solvents (the details follow after the list).1. Applicable Solvents2. Solvent Miscibility3. Solvent Boiling Point4. Column Specifications (maximum allowable pressure, flow rate, column volume, maximum temperature)5. Setting the Pump Limiter's Maximum Pressure6. HPLC System's Solvent Compatibility Applicable SolventsCheck solvent replacement applicability of the column. Please refer to page 60: Solvent Replacement Applicability of Organic SEC (GPC) columns.Please pay an extra attention as different pore-size columns even within the same column series may have different solvent replacement applicability. You may also check the solvent replacement applicability in the column-specific operation manual and Shodex website (https://www.shodex.com/en/dc/06/03/09.html). Solvent MiscibilityCheck miscibility/solubility of the desired new solvent and the solvent currently filled in the column. Please refer to Shodex website (https://www.shodex.com/en/dc/06/0115.html) for the miscibility of the solvents.THF, chloroform, DMF, and HFIP are miscible with each other. On the other hand, sodium trifluoroacetate is soluble in HFIP but difficult to dissolve in THF. Thus, if HFIP with sodium trifluoroacetate and THF are mixed, sodium trifluoroacetate will precipitate. Precipitation of salt in the HPLC system or column may damage the system and/or the column. Therefore, it is important to check solubility of the salt in addition to checking the miscibility of solvents. Solvent Boiling PointThe column pressure sometimes increases during the solvent replacement. Increasing the column oven temperature is an effective way of reducing the column pressure.However, setting the column oven temperature higher than the boiling point of the solvent makes the solvent to generate air bubbles. Since the bubbles may affect the filling condition of the packing material, please pay an attention when increasing the column oven temperature. Column SpecificationsPlease refer to the below table for the maximum pressure allowed per column and the recommended flow rate. Also, please check details of specifications described in the column-specific operation manual and Shodex website.< Column Specifications >Product SeriesGPC KF-800 seriesGPC KD-800 seriesGPC KF-400HQ seriesGPC HK-400 series(for GPC HK-402)GPC LF-804GPC LF-604GPC LF-404Flow Rate(mL/min)0.5 ~ 1.00.5 ~ 1.00.30.3 ~ 1.0Maximum Pressure(MPa/column)Maximum Temperature3.53.5725(20)3.53.53.5(°C)6060456060606066Solvent Replacement Method for Organic SEC (GPC) Columns
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