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 utilitarianism with respect to disutility. That is, positive utility functions as a tiebreaker in that it determines which outcome is better (or less bad) when the outcomes considered have equal disutility. 'Lexical threshold' negative utilitarianism says that there is some disutility, for instance some extreme suffering, such that no positive utility can counterbalance it. 'Consent-based' negative utilitarianism is a specification of lexical threshold negative utilitarianism, which specifies where the threshold should be located. It says that if an individual is suffering and would at that moment not "agree to continue the suffering in order to obtain something else in the future"