Performance validation of ScatterX78 against NIST reference materials

Introduction

The set of NIST reference materials RM 8011, 8012 and 8013 consist of highly dilute (0.005 wt.%) aqueous dispersions of gold nanoparticles with nominal particle sizes of 10, 30 and 60 nm, respectively. Generally these are intended for the evaluation and qualification of methodology and/or instrument performance related to the physical/dimensional characterization of nanoscale particles used in pre-clinical biomedical research. The reference materials were used to validate experimental SAXS data acquired with ScatterX78 and analyzed with the EasySAXS analysis software.

Experimental details

SAXS data were acquired on the Empyrean platform configured with ScatterX78 in combination with a focusing X-ray mirror and the PIXcel3D detector used in 1D mode. The liquid samples were loaded in a disposable quartz capillary and measured under ambient conditions. For the background measurement the capillary filled with water was used. The measurement time per sample was only 20 min.

Data reduction and analysis were done with the EasySAXS software. For particle size analysis an indirect Fourier transformation approach was used, yielding volume-weighted size distributions. The particle shape was assumed to be spherical. No a priori assumptions were made about the shape and modality of the size distribution curve.