samples, the sample introduction system was rinsed thoroughly with 1%
(v/v) HNO3 and 1% (v/v) HCl respectively before each analysis in sequence.
Fresh AgNP (50 and 100 nm) and AuNP (60 and 100 nm) suspensions
certified by TEM as quality control samples were also prepared daily
during each analysis to ensure the accuracy of SP-ICPMS.