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USP and Ph. Eur. Allowable adjustments calculator
Harmonized Pharmacopeia Allowable Adjustments of Chromatographic Conditions - Isocratic Elution
| Component | Condition as per monograph | Adjustable from | Adjustable to | Limit |
|---|---|---|---|---|
| Stationary Phase | No change of the identity of the substituent (e.g. no replacement of C18 by C8); the other physico-chemical characteristics of the stationary phase (i.e. chromatographic support, surface modification and extent of chemical modification) must be similar; a change from totally porous particle (TPP) columns to superficially porous particle (SPP) columns is allowed provided the above-mentioned requirements are met. | |||
| Mobile phase minor component (<50%) | 35.32 | 55.32 | ± 30 % (relative) for minor components, but no component is altered by more than ± 10 % absolute. A minor component comprises less or equal than (100/n) %, where n being the total number of components. Cannot be reduced to zero | |
| pH of aqueous component of mobile phase | 0.80 | 1.20 | ± 0.2 pH units, unless otherwise prescribed. | |
| Concentration of salts in buffer component of mobile phase (mM) | 19.80 | 24.20 | ±10 % | |
| Column Temperature (°C) | 12 | 32 | ±10 °C, where the operating temperature is specified, unless otherwise prescribed | |
| Component | Condition as per monograph | Adjusted conditions | Remarks | |
| Column Length (mm) | The particle size and/or length of the column may be modified provided that the ratio of the column length (L) to the particle size (dp) remains constant or in the range − 25 % to + 50 % of the prescribed L/dp ratio. | |||
| Column Diameter (mm) | In the absence of a change in particle size and/or length of the column, the internal diameter of the column may be adjusted | |||
| Particle Size (µm) | Alternatively (as for the application of particle size adjustment to superficially porous particles), other L/dp combinations can be used provided that the number of theoretical plates (N) is within -25% to +50% | |||
| L/dp | 50.00 | 50.00 | ||
| The column with desired dimension | Can be used. | |||
| L/dp deviation | 0.00% | |||
| Flow Rate (mL/min) | The New flow rate as per the desired column dimension is 1.322 mL/min | After an adjustment due to a change in column dimensions, an additional change in flow rate of ± 50 % is permitted | ||
| Injection Volume (µL) | The injection volume for the desired column dimension is 33 µL | When the column dimensions are changed, the injection volume may be adjusted accordingly. | ||
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| Selection by : | Description | Number | ||
| Description according to Pharm. Eur. Pharm. Eur. 11, 4.1.1. Reagents 2023 | Number | Recommended Phenomenex Column | ||
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