Loratidine is the active ingredient in the antihistamine Claritin®. Mass spectral analysis of loratidine shows M⁺ at m/z = 382 and M⁺ at m/z = 384 in an approximate ratio of 3:1 in intensity. This data indicates that loratidine contains fluorine.

Question

Quizplus · Accepted Answer

The presence of peaks at m/z = 382 and 384 in a 3:1 ratio suggests the presence of chlorine (Cl) in the molecule, not fluorine (F), as chlorine naturally occurs as approximately 75% ^35Cl (m/z = 35) and 25% ^37Cl (m/z = 37), leading to the observed isotopic pattern.

Loratidine Is the Active Ingredient in the Antihistamine Claritin®