The Analysis of Polymer Additives using Supercritical Fluid Chromatography

By DJ Tognarelli

Download PDF August 19, 2022

  • Industry

  • Technique

Introduction

SFC has been well established for chiral pharmaceutical separations and purifications and has also recently been utilized for achiral pharmaceutical compounds.

As SFC column technology continues to be explored, the SFC is being applied to various industries analyzing a wider range of compounds than ever before.

A typical polymer additive separation using HPLC can take upwards of 40 minutes. The speed of SFC should be able to significantly reduce that analysis time if it can successfully be applied to polymer additive separations.

Jasco SF-2000

Experimental

Results

Figure 1. Stack chromatograms of Tinuvin 327 (6ug/uL) , Irgafos 168 (4ug/uL), Irgafos 168 Phosphate (8ug/uL)and Chimassorb 81 (10ug/uL). Conditions: Column Luna C18 (150 x 4.6 mm, 5um) , Flow rate 3mLs/min (100% CO2), Temperature 40C, Back Pressure Gradient 150 bar to 250 bar over 4 minutes, 220nm, 50uL Injection each. At these concentrations the detector was clearly overloaded with signal.

The chromatogram of the 4 polymer additive standards separated using a pressure gradient is shown in figure 1. As seen the concentration of each was too high and thus the concentration of each was reduced when a mixture of the 4 was created. Figure 2 shows the separation of that mixture using a solvent gradient, while figure 3 shows the separation using the same pressure gradient used in figure 1.

Figure 2. Chromatogram of Tinuvin 327 (0.8ug/uL), Irgafos 168 (1.5ug/uL), Irgafos 168 Phosphate (3ug/uL) and Chimassorb 81 mixture (0.8ug/uL) in Acetone . Conditions: Column Luna C18 (150 x 4.6 mm, 5um) , Flow rate 3mLs/min (Grad 0% to 20% Methanol over 6 minutes), Temperature 40C, Back Pressure 150bar, 220nm, 15uL Injection.
Figure 3. Chromatogram of Tinuvin 327 (0.8ug/uL), Irgafos 168 (1.5ug/uL), Irgafos 168 Phosphate (3ug/uL) and Chimassorb 81 mixture (0.8ug/uL) in Acetone. Conditions: Column Luna C18 (150 x 4.6 mm, 5um) , Flow rate 3mLs/min (100% CO2), Temperature 40C, Back Pressure Gradient 150bar to 200bar over 4 minutes, 220nm, 10uL Injection.

Conclusion

SFC successfully separated Irgafos 168, Irgafos 168 phosphate, Tinuvin 327 and Chimassorb 81 using only CO2 as the mobile phase on a C18 column.

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About the Author

DJ Tognarelli received his B.S. from the University of Richmond where he studied Analytical Chemistry. He is a Chromatography Applications Scientist at JASCO.