1-Chloroethyl chloroformate was used: for N-demethylation reaction during determination of multiple drugs of abuse in biological fluids using capillary electrophoresis with native fluorescence and laser-induced fluorescence detection as catalyst in chemoselective desilylation of silyl-protected alcohols as reagent in N-demethylation of tertiary amines to produce drug metabolite reference material for forensic toxicological applications as reagent to cleave benzhydryl groups from amines