Question: what are spectrometers

Jimi Wills answered on 15 Mar 2016:

A mass spectrometer is a machine that measures molecules.

I’ve worked with mass spectrometers for about 15 years. Mass spectrometers are like scales for weighing molecules… molecules are what cells are made of. If you weighed everybody in your class really accurately, you’d be able to tell who was whom just from their weight! And it’s exactly the same with molecules.

So using the mass spectrometer, I can tell other scientists what molecules are in their experiments, and I can tell them how much there is of each too. Then the other scientists can grow cells in a dish and compare cancer cells and normal cells, or cancer cells with and without drugs. This helps us figure out how cancer works, and how the drugs work.

A “column” is used to separate out different types of molecules, so we can measure them one at a time. It’s like a turnstile at a stadium or theatre, to make sure that people get to the ticket window one at a time.

The molecules are pumped into the “source” and it’s the part of the mass spec where molecules get turned into ions. This means they are given an electric charge, then the mass spec can move them around. It’s like when you rub a balloon and then move your hair around with it.

The electric charge in the source is about 2000-3500 volts. That’s 10 times the mains electricity in your house. And the temperature in the source is about 350 degrees C, which is hot enough to melt lead. And inside the mass-spec is a vacuum – there’s no air at all – just like in space.