Table 1.

Summary of detection and characterization methods used to evaluate silver content of consumer products.

Matrix	Techniqueb	Sample preparation and analysisa
		EPA	NIOSH
Textile	ICP	Cut textile sample from fabric and weigh (500–1000 mg, air-dry mass) Submerge sample in 5 mL HNO3 (concentrated, 69–71%, w/w) and 5 mL ultrapure water Cover beaker with watch glass, heat to ~ 100°C Digest in HNO3 Cool, add 3 mL H2O2 (30%) Heat to ~100°C, add H2O2 until effervescence is minimal Cool, filter through glass fiber filter Dilute with ultrapure water Analysis by ICP-MS	Cut textile sample from garment and weigh Digest with 15.6 M HNO3 at 95 °C for 70min Cool, add water + 30% H2O2 Heat, add H2O2 until effervescence stops Continue to heat for 120 min Cool, add 12.1 M HCl Heat for 10 min Cool, dilute with di water Analysis by ICP-AES MDL = 0.7mg Ag/kg textile
	SEM	Cut small piece of fabric from product Adhere fabric to SEM stub with carbon tape Ash piece of material and dust onto carbon tape on SEM stub Sputter coat with ~50 Å gold Image at 10 kV accelerating voltage	Remove individual fibers from garment using tweezers Mount fibers on carbon tape Sputter coat with ~50 Å gold/palladium Image at 20 kV accelerating voltage Cut textile sample from garment Ash at 350°C for 3 h in alumina crucible Disperse residue in deionized water Pass aliquot through 0.4 μm pore TEPC filter Section filter, mount on carbon tape Sputter coat with ~ 50 Å gold/palladium Image at 20 kV accelerating voltage
	TEM	Cut small piece of fabric from product Ash at <550 °C in muffle furnace Dust ashed sample onto carbon-coated TEM grids Suspend ashed sample in distilled water, immerse in sonicating bath, evaporate droplets on carbon-coated TEM grids Image at 120 kV using TEM	-
	UV–vis	Cut textile sample from garment Place sample in integrating sphere Measure absorption spectra from 350 to 700 nm	Cut textile sample from garment Place sample in integrating sphere Measure absorption spectra from 350 to 700 nm
Liquids	ICP	Gently shake product in original container Withdraw sample of known volume Dilute 1:10 with ultrapure water Dilute 1:100 with ultrapure water, add NHO3 to acidify Analysis by ICP-MS	Mix product and withdraw sample of known volume Digest as described for textiles Analysis by ICP-AES MDL = 0.001 mg Ag/L
	SEM	-	Mix product Pass aliquot through 0.1 μm pore TEPC filter Section filter, mount on carbon tape Sputter coat with ~ 50 Å gold/palladium Image at 20 kV accelerating voltage
	TEM	Place 10 μL droplet onto carbon-coated grid Dry TEM grid in desiccator Repeat until total sample volume reaches 20 μL Image at 120 kV accelerating voltage	Mix product Place 4 μL drop onto carbon-coated grid Air dry Image at 80 kV accelerating voltage
	UV–vis	Gently shake product in original container Dilute liquid with deionized water (as necessary) Dispense sample in 1-cm path length plastic cuvette Measure absorption spectra from 350 to 700 nm	Mix product Dilute liquid with deionized water (as necessary) Dispense sample in 1-cm path length plastic cuvette Measure absorption spectra from 350 to 700 nm
	DLS	Gently shake product in original container Pass sample through 1 μm hydrophilic Teflon filter Thermally equilibrate sample in instrument, analyze	Mix product Add aliquot to 10 mM NaCl solution Pass sample through 0.7 μm membrane filter Thermally equilibrate sample in instrument, analyze
	ISE	-	Mix product Dilute aliquot with deionized water (as necessary) Add ionic strength adjuster (5 M NaNO3)1:50 MDL = 0.015 mg/L
Plastics	ICP	Cut sample from plastic and weigh (500–1000 mg, air-dry mass) Digest as described for textiles Analysis by ICP-MS	-
	SEM	Cut small piece from plastic Prepare for microscopy as described for textiles	-

^aHNO₃, nitric acid; H₂O₂, hydrogen peroxide; HCl, hydrochloric acid; MDL, method detection limit; TEPC, track-etched polycarbonate; NaCl, sodium chloride; NaNO₃, sodium nitrate; -, matrix not evaluated.

^bICP, inductively coupled plasma (AES, atomic emission spectroscopy; MS, mass spectroscopy); SEM, scanning electron microscopy; TEM, transmission electron microscopy; UV-vis, ultraviolet-visible absorption spectroscopy; DLS, dynamic light scattering (photon correlation spectroscopy); ISE, ion selective electrode.