AASHTO T 392:2021 Standard Method of Test for Determination of Heavy Metal Content of Glass Beads Using X-Ray Fluorescence (XRF).
This test method covers the determination of the total heavy metal content of glass beads using X-ray fluorescence (XRF). Heavy metals include but are not limited to lead, antimony, and arsenic. This test method is intended as a quality assurance tool for agencies to verify the manufacturer’s certified test results for heavy metals provided in accordance with Environmental Protection Agency testing methods 3052, 60 lOB, and 6010C as they relate to compliance with Section 1504 ofMAP-21.
The values stated in SI units are to be regarded as the standard.
This test method is used to determine the total concentration of heavy metals using XRF testing. Testing may be performed with a handhcld portable XRF or a laboratory XRF.
3.2. For a handheld XRF, the glass beads to be tested are placed in a loose state in a sample cup with or without a helium flush.
3.3. For a laboratory model XRF, the glass beads can be tested either in a loose state in a sample cup, using helium flush or as a pressed pellet under vacuum.
Note 1—Testing the glass beads in a loose state using a helium flush is the preferred method.
This method is designed to identify the presence and concentration of heavy metals in samples of glass beads. The method determines the total concentration and may be used to determine compliance with total concentration limits in M 247.
XRF Spectrometer—Either a handheld portable or a laboratory model XRF spectrometer may be used. The XRF used must have a minimum limit of detection (LOD) that will allow accurate measurement for each heavy metal element.
5.2. Sample Cup— if the test includes using loose beads with or without a helium flush. use a thin- walled container to hold the loose glass beads. Sample cup includes a collar and cap.
5.3. Pressed Pellet Press—If the test includes using a vacuum in a laboratory model XRF, use a pressed pellet press to prepare the sample for testing.
5.4. MLier or Ring and Puck Mill—If the test includes using a vacuum in a laboratory model XRF, use a mixer or ring and puck mill to pulverize and blend the glass bead sample with the binding agent to prepare the pressed pellet for testing.
For loose samples of beads tested in a sample cup, polypropylene film, filter paper, and polyester fiber stuffing are needed.
6.1.1. Filrn—For detection of heavy metals, any thin film is acceptable. l2-im polypropylene is acceptable.
6.1.2. Filter Paper—Filter paper disk to fit over the sample.
6.1.3. Fiber Stuffing—Polyester fiber stuffing such as used for aquarium tilter or pillow tilling.
6.2. For pressed pellets, a binder is required to form the glass beads into a pellet.AASHTO T 392 pdf download.