Separation of NyQuil Active Ingredients on Zodiac HST C

Zodiac HST C effectively separates the active ingredients found in the over-the-counter cold medicine, NyQuil. While succinate and bromate co-elute early, acetaminophen, pseudoephedrine, doxylamine, and dextromethorphan are baseline resolved. The separation is driven by a combination of cation exchange, complex formation, and hydrophobic interactions, using a mobile phase of water, acetonitrile (MeCN, ACN), and triethylamine (TEA) phosphate, with UV detection at 205 nm.