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 and Negative Affect Schedule They chose terms that met a strong correlation to one corresponding dimension but exhibited a weak correlation to the other. Through multiple rounds of elimination and preliminary analyses with a test population, the researchers arrived at 10 terms for each of the two scales, as follows: The PANAS for Children (PANAS-C) was developed in an attempt to differentiate the affective expressions of anxiety and depression in children. The tripartite model on which this measure is based suggests that high levels of negative affect is present in those with anxiety and depression, but high levels of positive affect is not shared