Evaluation of analytical techniques to determine AQUI-S® 20E (eugenol) concentrations in water

There is a critical need in U.S. public aquaculture and fishery management programs for an immediate-release sedative, i.e. a compound that can be safely and effectively used to sedate fish and subsequently, allow for their immediate release. AQUI-S® 20E (10% active ingredient, eugenol; any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government) is being pursued for U.S. approval as an immediate-release sedative. As part of the approval process, data describing animal safety and efficacy are needed. Essential to conducting studies that generate those data, is a method to accurately and precisely determine AQUI-S® 20E concentrations in exposure baths. Spectrophotometric and solid phase extraction (SPE)–high pressure liquid chromatography (LC) methods were developed and evaluated as methods to determine AQUI-S® 20E (eugenol) concentrations in water, methods that could be applied to any situation where eugenol was being evaluated as a fish sedative. The spectrophotometric method was accurate and precise (accuracy, > 87%; precision, 86%; precision