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 number Negative number In mathematics, a negative number is a real number that is less than zero. Negative numbers represent opposites. If positive represents a movement to the right, negative represents a movement to the left. If positive represents above sea level, then negative represents below sea level. If positive represents a deposit, negative represents a withdrawal. They are often used to represent the magnitude of a loss or deficiency. A debt that is owed may be thought of as a negative asset, a decrease in some quantity may be thought of as a negative increase. If a quantity may have