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 or that its items are redundant. The PANAS does not encompass higher order mood states. Positive and Negative Affect Schedule The Positive and Negative Affect Schedule (PANAS) is a self-report questionnaire that consists of two 10-item scales to measure both positive and negative affect. Each item is rated on a 5-point scale of 1 "(not at all)" to 5 "(very much)". The measure has been used mainly as a research tool in group studies, but can be utilized within clinical and non-clinical populations as well. Shortened, elongated, and children's versions of the PANAS have been developed, taking approximately 5–10 minutes