Each common inactive ingredient in hand sanitizer gels serves a specific purpose. Water acts as a solvent and is necessary to allow the active ingredient alcohol to penetrate bacterial cells in order to kill them. Glycerin and propylene glycol are humectants to help prevent the loss of moisture in the skin. Isopropyl myristate is an emollient. Along with Vitamin E acetate, isopropyl myristate helps smooth skin. Carbomer is a thickening agent that causes the gel-like texture in hand sanitizers, and triethanolamine functions as a pH adjuster as well as promoting emulsification.
Two types of screening methods by GC/MS were utilized: 1) a volatile screening method for ingredients like ethanol, isopropanol and propylene glycol (see Figure 1) and 2) a semi-volatile screening method for ingredients like glycerin, Vitamin E acetate, and isopropyl myristate (see Figure 2).