Inductively coupled plasma mass spectrometry argon ions. Making the plasma from argon, instead of other gases, has several advantages. First, argon is abundant (in the atmosphere, as a result of the radioactive decay of potassium) and therefore cheaper than other noble gases. Argon also has a higher first ionization potential than all other elements except He, F, and Ne. Because of this high ionization energy, the reaction (Ar + e → Ar) is more energetically favorable than the reaction (M + e → M). This ensures that the sample remains ionized (as M) so that the mass spectrometer can detect it. Argon can be purchased
Copia: Foundations of the Abundant Style on Quintillian's rhetorical guide, "Institutio Oratoria". The first chapter of book 10 in Quintillian's "Oratoria" is titled ""De copia verborum"". This is quite possibly where Erasmus received his most direct inspiration for the book. In that 10th chapter, Quintillian declined to give examples for employing the abundant style, on the grounds that each individual case requires a unique solution. This left the door open for Erasmus to detail the abundant style in "Copia". Erasmus acknowledges Quintillian in the preface, and borrows from him (and other classical authors) throughout "Copia", sometimes citing, sometimes not. As further revisions of "Copia" are printed,