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 by the Czech jurist Karel Vasak, may include other civil and political rights such as police protection of person and property and the right to counsel, as well as economic, social and cultural rights such as food, housing, public education, employment, national security, military, health care, social security, internet access, and a minimum standard of living. In the "three generations" account of human rights, negative rights are often associated with the first generation of rights, while positive rights are associated with the second and third generations. Some philosophers (see criticisms) disagree that the negative-positive rights distinction is useful or valid.