Nanoparticle tracking analysis versus dynamic light scattering: Case study on the effect of Ca 2+ and alginate on the aggregation of cerium oxide nanoparticles.

•Effect of Ca2+ and alginate on stability of CeO2 NPs studied.•Dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA) employed.•Aggregation of CeO2 NPs with alginate exhibited a heteroaggregation mechanism.•DLS and NTA provided insight into aggregation mechanisms.•DLS and NTA are complementary techniques to study nanoparticles in water.