After nebulization of nanoparticle solution mixing with the metal
ion, the dissolved metal ion was distributed homogeneously in the same aerosol drop. The background signal was effected by them (Laborda et al., 2011). 5σ iterative algorithm criterion and short dwell
time are two ways to discriminate the nanoparticle signal from the dis- solved metal ion. The raw signals of the mixed solution of 25 ng/L 60 nm AuNPs and 1 μg/L Au+ under different dwell time were shown in Fig.