Material Identification of Single-Organic Particles Realized by Observing Their Field-Induced Translations

A method is proposed that can efficiently identify the material of a single-organic particle; the identification is realized by improving an apparatus formerly used to observe the field-induced translations of particles. Using this new setup, the material of an unidentified organic particle can be determined without consuming the sample. Specifically, the diamagnetic susceptibility χ
_DIA
of the particle was obtained from its translating velocity induced in a field-gradient produced by an Nd magnetic circuit, and its material was identified by comparing the experimental χ
_DIA
value with a list of published values. In principle, the proposed method of identification based on the χ
_DIA
value is effective even for micrometersized particles because the mass measurement of the sample is unnecessary. Hence, the method can be used to thoroughly extract and identify a rare material from a mixture of heterogeneous particles without consuming the sample, before performing a refined analysis.