Interlaboratory comparison of analytical methods for residual ethylene oxide in medical device materials

An interlaboratory comparison of four gas chromatographic test procedures for the quantification of ethylene oxide in an acrylic polymer was conducted by thirteen laboratories. The procedures included extractions with water, acetone, and N,N-dimethylformamide, and headspace gas analysis. The results of this study, using only the data from the labs that did not deviate from the procedure, showed that the average estimated total coefficient of variation ranged from 8 to 22% for the four different methods. Each of the methods is suitable for use as a reference test method for determining residual ethylene oxide in polymeric materials.