Book excerpt: Ionization Methods in Organic Mass Spectrometry is a basic practical guide for scientists of all disciplines who wish to analyse samples by organic mass spectrometry. Concentrating on instrumental operation, this book gives step-by-step instructions on how to set up, and how to achieve the best results, using a range of ionization methods, including atmospheric pressure chemical ionization, electrospray ionization and matrix assisted laser desorption ionization. Ionization Methods in Organic Mass Spectrometry will enable a beginner, or practitioner with limited experience, to choose the most appropriate ionization technique in application areas such as biomolecules, drugs and metabolites, pesticides, polymers and many other organic compounds. It will be a valuable practical guide for technicians, graduates, students or researchers - or indeed anyone new to practical organic mass spectrometry.