10-12-2012

Increase sensitivity analyzing trace elements by using electroThermal vaporization

By using electrothermal vaporization (ETV) for sample introduction, SPECTRO has greatly improved the sensitivity of the SPECTRO ARCOS ICP-OES spectrometer for material analysis applications. Trials verify that detection limits can be improved by an order of magnitude. At a much lower cost, ICP-OES penetrates the sensitivity range of glow discharge sector field mass spectrometers, opening new application areas in solid material analysis for ICP-OES.

Typically, ICP-OES samples are first dissolved and then introduced to the instrument using a nebulizer. When using electrothermal vaporization (ETV), however, the solid samples are vaporized in an oven with a temperature range up to 3,000 degrees Celsius. The graphite vaporization chamber uses argon as the inert gas. After vaporization, the analyte is transported as a dry aerosol to the ICP instrument with an argon/reaction gas stream. Sample vaporization takes just two minutes.

“With ETV, the sample is not diluted, but flows to the instrument as a concentrated stream of micro particles" explains Olaf Schulz, who is responsible for SPECTRO's line of ICP-OES products. “This increases the sensitivity of the ICP instrument significantly. We shifted the sensitivity range of the SPECTRO ARCOS into the range of a few micrograms per kilogram. This allows for applications in pure metal analysis with ICP-OES technology possible for the first time. A much larger sample amount can be analyzed compared with laser ablation, which is better suited to spot testing. Homogeneity differences within a sample also have less of an influence on the analytical result. One example is the examination of cathodically obtained copper for electrical wires, where even trace amounts of impurities can greatly impair electrical conductivity. For this reason, material analysis is imperative.

“Our trials with pure copper indicate that the SPECTRO ARCOS can achieve similar sensitivity as a glow discharge sector field mass spectrometer. The corresponding application report documenting this can be requested at www.spectrolive.com" notes Olaf Schulz.  

ETV analysis opens up whole new possibilities especially for samples that are difficult to dissolve. No longer is it necessary to create solutions of ceramic materials, such as the extremely resistant silicon carbide, using time-consuming chemical digestion.

ETV Systems is now user-friendly
Electrothermal vaporization as a method for sample preparation has been available on the market for some time. “However, first generation ETV systems were often difficult to operate, not especially suited to routine use and prone to errors. There has been major success in making ETV more compact and user friendly" reports ICP-OES Product Manager, Olaf Schulz.

SPECTRO offers the ICP-OES ARCOS together with the ETV system as a complete system with an autosampler for up to 50 solid samples in its range of products.

For more information, please visit www.spectro.com