Monday, April 24, 2006

DARTs and MS

I'm sure all the mass spec people have heard about this before because it is so cool and also one year old news. It's a new ionization method called DART (direct analysis in real time) invented by Robert B. Cody of JEOL USA and James A. Laramee of EAI Corp. It is a sample introduction system that can be coupled to a mass spectrometer, currently only coupled to a MS by JEOL.
The major difference here, compared to other mass specs, is the sample inlet is at atmospheric pressure. You can hold an object, such as an orange, up in front of the sample cone and get a reading of masses detected and find fungicides.

This technique works by applying an electrical potential to a gas (N2 or H2) to form a plasma that interacts with the sample and the atmosphere.

It took me a minute to picture the instrument layout in my head, I couldn't, so I went to the website. The path of the ion: First, gas is fed in, a plasma is formed, then the instrument opens up to the atmosphere. So, the open region is between the plasma torch and the sample cone. Then, the rest of the mass spec, the one they use happens to be a time-of-flight.

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