ABSTRACT
In the 1970s, characterization of cerebrospinal fluid (CSF) began in earnest and as the technology for its analysis developed, much was learned about the cation, anion, and nonelectrolyte content of CSF. In the 1980s, significant discoveries within CSF included sphingolipids, brain-specific proteins, nucleic acids, transfer ribonucleic acids, and amino acids. The attempt to identify sleep molecules in CSF requires an efficient method for screening its molecular content. Electrospray ionization and matrix-assisted laser desorption/ionization mass spectrometry both offer molecular weight information on the types of compounds. While molecular weight information is of course useful in the preliminary stages of molecular characterization, it is also important to gather structural information. Tandem mass spectrometry, with its ability to induce fragmentation and perform successive mass spectrometry experiments on these fragment ions, is generally used to obtain this structural information. Fragmentation is usually achieved by inducing ion/molecule collisions.
