Residual solvents are organic volatile chemicals used in synthesis or purification processes, and their presence—if left uncontrolled—can pose toxicological, chemical reactivity, or stability concerns. Pinnacle Compounds utilizes Gas Chromatography coupled with Mass Spectrometry (GC-MS) to identify and quantify Class I, II, and III residual solvents in accordance with the International Council for Harmonisation (ICH) Q3C guidelines. Class I solvents (e.g., benzene, carbon tetrachloride) are strictly prohibited; Class II solvents (e.g., methanol, toluene, dichloromethane) must fall below tightly regulated exposure limits; and Class III solvents (e.g., ethanol, acetone) are permissible in limited quantities. Our GC-MS testing methods are validated to detect residual solvent levels in the parts- per-million (ppm) range, thereby ensuring that final lyophilized peptides and research compounds are both safe and chemically stable for sensitive experimentalprocedures.