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
Negative and positive rights Under the theory of positive and negative rights, a negative right is a right "not to be" subjected to an action of another person or group—a government, for example—usually in the form of abuse or coercion. As such, negative rights exist unless someone acts to "negate" them. A positive right is a right "to be" subjected to an action of another person or group. In other words, for a positive right to be exercised, someone else's actions must be "added" to the equation. In theory, a negative right forbids others from acting against the right holder, while a positive right