Commerical reference shape standards use in the study of particle shape effect on laser diffraction particle size analysis
The purpose of this paper is to describe the use of LGC Promochem AEA 1001 to AEA 1003 monosized fiberanalog shape standards in the study of the effect of particle shape on laser diffraction (LD) particle size analysis (psa). The psa of the AEA standards was conducted using LD psa systems from Beckman Coulter, Horiba,; Malvern Instruments. Flow speed settings, sample refractive index values,; sample cell types were varied to examine the extent to which the shape effect on LD psa results is modified by these variables. The volume; number probability plots resulting from these measurements were each characterized by a spread in the particle size distribution that roughly extended from the breadth to the longest dimension of the particles. For most of the selected sample refractive index values, the volume probability plots were characterized by apparent bimodal distributions. The results, therefore, provide experimental verification of the conclusions from theoretical studies of LD psa system response to monosized elliptical particles in which this apparent bimodality was the predicted result in the case of flow-oriented particles. The data support the findings from previous studies conducted over the past 10 years that have called into question the verity of the tenets of,; therefore the value of the application of, the equivalent spherical volume diameter theory; the random particle orientation model to the interpretation of LD psa results from measurements made on nonspherical particles.
Richard N. Kelly2Email:RKelly@prdus.jnj.com?Jacqueline Kazanjian1
[1] Yves Rocher North America Inc, Exton, PA ;[2] Johnson & Johnson Pharmaceutical Research & Development, LLC, Room P-1029 McKean & Welsh Roads, 19477-0776 Spring House, PA
