Chemical ionization source, the reagent gas is present in large excess compared to the analyte. Electrons entering the source with energy around 200-500 eV will preferentially ionize the reagent gas. Then, the ion/molecule reactions produces more stable reagent ions and the resultant collisions with other reagent gas molecules will create an ionization plasma. Positive and negative ions of the analyte are formed by reactions with this plasma. The following reactions are possible with methane as the reagent gas. If ammonia is the reagent gas, For isobutane as the reagent gas, Self chemical ionization is possible if the reagent ion is an ionized
Positive element to the natural order on the real numbers, but only to some extent. For example, it respects multiplication by positive reals and addition of self-adjoint elements, but formula_76 need not hold for positive elements formula_77 with formula_78 and formula_79. Positive element In mathematics, especially functional analysis, a self-adjoint (or Hermitian) element formula_1 of a C*-algebra formula_2 is called positive if its spectrum formula_3 consists of non-negative real numbers. Moreover, an element formula_1 of a C*-algebra formula_2 is positive if and only if there is some formula_6 in formula_2 such that formula_8. A positive element is self-adjoint and thus normal. If