ASTM D3335 Low Concentrations of Lead, Cadmium, and Cobalt in Paint by Atomic Absorption Spectroscopy

Scope:

In ASTM D3335 government regulatory authorities set the maximum number of heavy metals that can be present in specific coatings. To verify compliance, this test technique includes a thoroughly documented approach for determining low quantities of lead, cadmium, and cobalt in both aqueous and solvent-reducible coatings.

Procedure:

Dry ashing is used to prepare a liquid coating or dried film specimen for the ASTM D3335 test analysis. Atomic absorption spectroscopy is used to quantify the amount of lead, cadmium, and cobalt in an acid extract of the ash.

Specimen size:

Aliquots of the 1 mg/mL standard lead, cadmium, and cobalt solution are used for the ASTM D3335 test.

Data:

The following formula was used to calculate the mean concentrations of lead, cadmium, and cobalt in the nonvolatile component of the sample:

lead, cadmium or cobalt, ppm (mg/kg) in nonvolatile = (C × F × 5000) / (NV × S)

where: 

C = concentration of lead, cadmium, or cobalt in the aspirated specimen solution, (µg/mL)

F = dilution factor from 9.9 (volume diluted to/volume of aliquot)

NV = percent nonvolatile of paint sample (use 100 if the sample was a dried film)

S= sample, g

Conclusion:

ASTM D3335 is used to determine the amount of lead, cadmium, and cobalt in the nonvolatile component of liquid coatings and dried films. The measurement of lead in samples containing antimony pigments is not possible with this test method.