The Inductive Coupled Plasma Machine: A Look into The Technology Behind Catalytic Converter Analysis


In the world of scrap vehicle parts, there’s one piece in particular that can be as valuable as the car itself – and sometimes even more! Catalytic converters are devices that control vehicle emissions through a catalyst made of platinum, palladium, and rhodium. Because they contain precious metals, converters are extremely valuable to scrap metal and automotive recyclers.

For this reason, when converters are recycled, they end up at a toll-refiner’s facility. This is where converters are cut, crushed, and commingled in order to extract the precious metals they contain. To help you get paid based on the amount of metals found in your material, toll-refiners have to analyze your converters with two primary technologies: X-ray Fluorescence (XRF) benchtop and Inductive Coupled Plasma (ICP).

We asked our laboratory manager, Alex Benoit, to give us an in-depth explanation about ICP to help you understand how your material is analyzed – and how you get paid based on the science behind it.

What is ICP and How Does it Work?

The ICP machine determines the amount of platinum, palladium, and rhodium in your converters by measuring the light intensity of each metal. Let’s take a look at the steps behind this type of analysis.

In contrast to the XRF benchtop machine, ICP requires a liquid sample. Once the sample is prepared, it gets aspirated by a peristaltic pump until it enters the nebulizer. The sample is then mixed with argon gas to create fine droplets, which move to the spray chamber.

The role of the spray chamber is to separate the finest droplets from the bigger ones. This step is necessary because the finest droplets will provide the most accurate results.

Once the finest droplets are isolated, they move into the plasma, which is heated to around 10,000 degrees Celsius (18,032 degrees Fahrenheit). At this extremely high temperature, the atoms of the sample absorb a lot of energy, and when this energy is expulsed from the plasma, it emits light.

Depending on which element we’re analyzing, the light intensity will be at different wavelengths. To determine the exact amount present, the intensity of the wavelength is measured for each element.

Why PMR Uses ICP

At PMR, we believe in helping you achieve the most from your material. For this reason, we use both XRF and ICP to analyze your catalyst material. With ICP, the number-one benefit is accuracy, which helps us provide the best possible financial returns for your converters.

For more information, visit PMR’s Resource Center.

Published: April 13, 2023
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