What is used to send in a sample into the spectrometer?

Answer 1

A test tube.

Answer 2

If you mean a mass spectrometer, one efficient way is electrospray. The sample chamber and pathway to the mass analyzer is under high vacuum. There are also a couple of plates with tremendous electrical potential difference between them. The user sprays a small amount of dissolved sample into the chamber. The potential ionizes the "atomized" sample, and another potential accelerates the ions into the mass analyzer.

In two other ways, the sample is already in the sample chamber. In fast-atom bombardment, there is a bit of Cf-252 there too. Alpha particles hit the sample and break it up into ions, which are accelerated to the mass analyzer.

Or one blends the sample with an organic compound that photolyzes explosively. The user hits the mix with a laser beam, the organic compound destructs, and the sample, now reduced tomolecule-size and ionized, is accelerated.