Laser Diffraction Particle Size Analysis of Mycotoxin Samples
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Contributing OfficeCenter for Food Safety and Applied Nutrition
Abstract
Due to heterogenous distribution of mycotoxins in foods, mycotoxin samples are required to be homogenized prior to extraction. Required homogeneity threshold of samples is often defined by sample particle sizes (e.g., sample particles pass through #20 sieve, 850 µm). Conventionally, the measure of particle size is achieved via manual or mechanic sieving, a time-consuming and laborious process. In this study, particle size distributions of mycotoxin samples are characterized using dry and/or wet dispersion methods developed on a laser diffraction particle size analyzer. Key parameters such as dispersant solvent, particle type, refractive index, obscuration rate, scattering model, and feed rate are compared and evaluated. The performance of selected parameters used for particle size analysis are tested using reference materials, followed by the analysis of representative food matrices that are commonly used for mycotoxin analysis. This study compares particle size distributions (e.g., Dv90<850 µm) for corn, wheat flour, peanut butter, raisin, and oat samples prepared using established dry, cryogenic milling, or water slurry procedures in an effort to characterize homogeneity for representative sampling . Compared to sieving, laser diffraction-based measurements offer a more practical and time-efficient alternative for particle size analysis and can be incorporated into routine sample analysis to characterize homogeneity of prepared samples.