New Test Method for Determination of Lead in New Paint Samples through the Standardization of XRF via Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES)
1. Scope
1.1 This test method specifies a procedure for the collection, drying, homogenization and analysis of new paint samples for the determination of lead content using the standardization of an X-ray fluorescence analyzer (XRF) against inductively coupled plasma-optical emission spectroscopy (ICP- OES).
1.2 This test method should be used by analysts experienced in the use of XRF, the interpretation of spectral and matrix interferences, and procedures for their correction.
1.3 This test method cites specific methods for preparing test solutions of dried, homogenized new paint samples for analysis.
1.4 It is the user’s responsibility to ensure the validity of this test method for sampling materials of untested matrices.
1.5 No detailed operating instructions are provided because of differences among various makes and models of suitable pXRF analyzers. Instead, the analyst shall follow the instructions provided by the manufacturer of the particular instrument. This test method does not address comparative accuracy of different devices or the precision between instruments of the same make and model. However, this test method used an Olympus Vanta C pXRF analyzer employing the manufacturer’s GeoChem(2) method.
1.6 This test method contains notes that are explanatory and are not part of the mandatory requirements of this test method.
Keywords
XRF analysis; standardization of XRF using ICP-OES; new paint analysis; lead
Rationale
The standard will focus on a novel methodology for low- and middle-income countries to standardize the use of pXRF for studying and mandating policy for lead (Pb) in new paints by incorporating a resultant correlation between pXRF and ICP-OES data. While pXRF can be a valuable screening tool for estimating the concentration of Pb in paint, the accuracy of this technique is affected by its sensitivity to different matrices and sample thicknesses, which may result in different observed concentrations of Pb. Currently, there is no direct method to determine Pb in new paint outside conventional, spectroscopic methods, which are both cost prohibitive and complex to use. This method
fills the gap in low- and middle-income countries to analyze new paint samples as more regulations are being implemented and enforced.
