Ledoux & Company are pioneers in the spent automotive catalyst testing industry. For more that 41-years, we have been analyzing automotive catalysts to determine the amounts platinum (Pt), palladium (Pd), and rhodium (Rh). We have the insight, experience and know-how to test and analyze spent automotive catalysts. Our test methods provide precise and accurate results for our worldwide clients.
In 1975, Ledoux & Company was the exclusive contractor to General Motors for analyzing their automotive catalysts.
Over the past few years, significant changes have been made in the base metal composition, catalyst technology and precious metal loadings. Today, honeycomb catalysts are most common and the precious metals are loaded on metal monolith supports, silica carbide or traditional aluminum magnesium silicate base. Other rare earth and base metals may be present at high concentrations.
Therefore, when analyzing samples, the testing laboratory must realize that each test method has its own limitations. Some methods may require expensive equipment and highly skilled chemists. The fundamental question is which test method to use or even if one method is better than the other. This is where Ledoux & Company is separated from the others.
The approach we have adopted is to eliminate the matrix using an effective group separation technique and to isolate precious metals before final assays. For example,
- lead fire assay through gold, platinum and palladium collections
- nickel sulfide and copper collections
- sulfide group separations, using thiosulfate, hydrogen sulfide, etc.
- reduction to metals using hydrazine, mercurous chloride, zinc, aluminum, borohydride, etc.
The alternative is to determine the metals without any matrix separation. For example,
- acid dissolution
- fusion methods followed by;
- ICP-emission or ICP-Mass