Detection of Agglomerates Using Hydrodynamic Chromatography Hyphenated with Single Particle Inductively Coupled Plasma Mass Spectrometry

Abstract

A fast method for the detection of nanoparticles and their state of agglomeration was 10 developed by combining hydrodynamic chromatography (HDC) and single particle inductively 11 coupled plasma mass spectrometry (spICP-MS). Gold nanoparticles were measured under 12 different conditions including the simulation of one of the most important human body functions, 13 the human digestion. Nanoparticle detection and characterization was clearly demonstrated by the 14 analysis of individual particles and a mixture of 30, 60, 100 and 200 nm particles at mass-based 15 concentrations in the ngL-1 (ppt) range. For HDC a clear linear relationship was observed between 16 the retention time and the square root of the particle diameter. An agglomeration experiment to 17 determine the packing density of the detected particles showed that it is possible to determine 18 whether the detected particles are primary particles or agglomerates. In addition, the application of 19 HDC hyphenated with spICP-MS was able to elucidate the fate of nanoparticles in the 20 gastrointestinal track. The results showed that primary gold particles that enter the body in the 21 saliva stage, agglomerate in the stomach to larger sized agglomerates which de-agglomerate back 22 to the primary particles in the intestine stage. The results of this experiment show that 23 HDC-spICP-MS is able to detect nanoparticles and agglomerates thereof in complex matrices. 24 25