The production and use of engineering nanomaterials (ENMs) leads to the release of manufactured or engineered
nanoparticles into environment. The quantification and characterization of ENMs are crucial for the assessment
of their environmental fate, transport behavior and health risks to humans. To analyze the size distribution and
particle number concentration of AgNPs and AuNPs in environmentalwater and track their stability at lownumber
concentration, a systematic study on SP-ICPMS was presented. The Poisson statistics was used to discuss the
effect of dwell time and particle number concentration theoretically on the detection of NPs in solution by SPICPMS.
The dynamic range of SP-ICPMS is approximately two orders of magnitude. The size detection limits for
silver and gold nanoparticle in ultrapurewater are 20 and 19 nmrespectively. The detection limit of nanoparticle
number concentration is 8 × 104 particles L−1. Size distribution of commercial silver and gold nanoparticle dispersions
is determined by SP-ICP-MS,whichwas in accordancewith the TEMresults. High particle concentration
recoveries of spiked AgNPs and AuNPs are obtained (80–108% and 85–107% for AgNPs and AuNPs respectively in ultrapure
and filtered naturalwater). It indicates that SP-ICPMS can be used to detect AgNPs and AuNPs. The filtration study
with different membranes showed that filtration might be a problematic pre-treatment method for the detection of
AgNPs and AuNPs in environmental water. Furthermore, the stability of citrate-coated AgNPs and tannic acid-coated
AuNPs spiked into filtrated natural and waste water matrix was also studied at low concentration using SP-ICP-MS
measurements. Dissolution of AgNPswas observed while AuNPs was stable during a ten day incubation period. Finally
SP-ICPMS was used to analyze NPs in natural water and wastewater. Theresults indicate that SP-ICPMS canbeusedto
size metallic nanoparticles sensitively of low concentration under realistic environmental conditions.The production and use of engineering nanomaterials (ENMs) leads to the release ofmanufactured or engineered
nanoparticles into environment. The quantification and characterization of ENMs are crucial for the assessment
of their environmental fate, transport behavior and health risks to humans. To analyze the size distribution and
particle number concentration of AgNPs and AuNPs in environmentalwater and track their stability at lownumber
concentration, a systematic study on SP-ICPMS was presented. The Poisson statistics was used to discuss the
effect of dwell time and particle number concentration theoretically on the detection of NPs in solution by SPICPMS.
The dynamic range of SP-ICPMS is approximately two orders of magnitude. The size detection limits for
silver and gold nanoparticle in ultrapurewater are 20 and 19 nmrespectively. The detection limit of nanoparticle
number concentration is 8 × 104 particles L−1. Size distribution of commercial silver and gold nanoparticle dispersions
is determined by SP-ICP-MS,whichwas in accordancewith the TEMresults. High particle concentration
recoveries of spiked AgNPs and AuNPs are obtained (80–108% and 85–107% for AgNPs and AuNPs respectively in ultrapure
and filtered naturalwater). It indicates that SP-ICPMS can be used to detect AgNPs and AuNPs. The filtration study
with different membranes showed that filtration might be a problematic pre-treatment method for the detection of
AgNPs and AuNPs in environmental water. Furthermore, the stability of citrate-coated AgNPs and tannic acid-coated
AuNPs spiked into filtrated natural and waste water matrix was also studied at low concentration using SP-ICP-MS
measurements. Dissolution of AgNPswas observed while AuNPs was stable during a ten day incubation period. Finally
SP-ICPMS was used to analyze NPs in natural water and wastewater. Theresults indicate that SP-ICPMS canbeusedto
size metallic nanoparticles sensitively of low concentration under realistic environmental conditions.