Dr. Florian Meier(a), Dr. David Müller(b), Zhengchao You(c), Dr. Steffen Weidner(c), Dr. Thorsten Klein(a)
(a)Postnova Analytics GmbH, (b)Centre Suisse d’Electronique et de Microtechnique (CSEM), (c)Bundesanstalt für Materialforschung und -prüfung (BAM)
Introduction
Asymmetrical Flow Field-Flow Fractionation (AF4) is a powerful tool for the separation of particles in the size range of approximately 1 - 3000 nm. However, particularly for polydisperse samples, analysis times may easily reach one hour or longer, hampering its application to high-throughput analyses. One possibility to significantly reduce analysis times in AF4 is the application of a miniaturized fractionation cartridge [1,2].
Miniaturized Asymmetrical Flow Field-Flow Fractionation
In miniaturized AF4 (mAF4), both external dimensions as well as the separation area are significantly reduced in comparison to a conventional analytical fractionation cartridge (Figure 1).
The benefits of mAF4 include:
• Significantly reduced sample consumption and sample dilution giving improved limits of detection
• Improved compatibility with mass spectrometric detection systems due to lower flow rates
• Significantly reduced analysis time
The reduced analysis time is a major advantage of mAF4 as demonstrated in figure 2 where the elution times for a mixture of three gold nanoparticle size standards (10 nm, 30 nm and 60 nm) could be dramatically reduced in comparison to conventional AF4.
Conclusion
Miniaturized Asymmetrical Flow Field-Flow Fractionation is a powerful complement to AF4 performed with a conventional analytical cartridge. Its low operational costs along with its fast analysis times and low sample consumption renders mAF4 a valuable tool for fast screening analyses and studies, when fully optimized peak resolution is not required.
References
[1] Müller D., Cattaneo S., Meier F., Welz R., deMello A.J., Frontiers in Chemistry, 2015, 3.
[2] You Z., Meier F., Weidner S., Separations, 2017, 4(1), 8-19.
