Equivalency of hydrochloric acid and distilled water extraction media for determining residual ethylene oxide in medical devices.

An alternate method for determining residual ethylene oxide (EtO) in medical devices was compared with the aqueous extraction method suggested by the Association for the Advancement of Medical Instrumentation (AAMI). Residual EtO was extracted from EtO-sterilized samples of acrylic polymer (XT250-301 glass-tinted formulation) in pellet form by immersion in 1 M HCl at 37 +/- 2 degrees C (alternate method) or immersion in distilled water (AAMI method). The EtO residuals in the extracts were determined using gas chromatography and were statistically compared using a two-sample t test. Results obtained using the alternative method agreed within 10% of those obtained using the AAMI method.