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 or "positive") requires both kinds of duties at once. In other words, Shue says that honouring a right will require avoidance (a "negative" duty) but also protective or reparative actions ("positive" duties). The negative positive distinction may be a matter of emphasis; it is therefore unhelpful to describe "any right" as though it requires only one of the two types of duties. To Shue, rights can always be understood as confronting "standard threats" against humanity. Dealing with standard threats requires all kinds of duties, which may be divided across time (e.g. "if avoiding the harmful behaviour fails, begin to repair