Table 1.

Comparison of Average Particle Size Measured by spICP-MS to the TEM results provided by the supplier. Particle Number Concentration and Au concentration recovery determined by spICP-MS

AuNP	Au Conc., μg mL−1 a	NP Number Concentration NP mL−1 b	TEM Diameter (nm)c	spICP-MS Diameter (nm)c	spICP-MS NP Number & Au Conc. Recovery (%)c
NIST RM 8012,30 nm	48.17 d	2.3 × 1011	27.6 ± 2.1e	26.8 ± 3.3	100.3 ± 2.2
NIST RM 8013,60 nm	51.86 d	2.9 × 1010	56.0 ± 0.5e	55.3 ± 6.2	101.7 ± 4.1
20 nm	56.60	7.0 × 1011	20.3 ± 1.6	20.5 ± 2.9	85.0 ± 4.8
50 nm	56.80	4.6 × 1010	49.7 ± 3.9	48.3 ± 5.3	95.5 ± 3.2
80 nm	56.69	1.1 × 1010	80.1 ± 6.3	78.0 ± 7.1	95.8 ± 6.6
100 nm	56.60	5.8 × 109	98.9 ± 7.8	95.8 ± 6.6	102.4 ± 2.0
150 nm	56.60	1.7 × 109	149.9 ± 11.8	154.2 ± 15.2	100.6 ± 3.2

^aInformation provided by NIST Reports of Investigation [38, 39] for RM 8012 and RM 8013 and consumer specification from Ted Pella, Inc. for the 20, 50, 80, 100, and 150 nm AuNPs

^bValue obtained using the Au concentration and TEM mean diameter, assuming monodispersed, spherical particles

^cUncertainties correspond to single standard deviations of multiple determinations

^dMass fraction expressed as μg g⁻¹

^eExpanded uncertainty of the mean for 95 % coverage, but only measurement repeatability was accounted for