Estimation of halothane in tissues by gas chromatography

Halothane was extracted from tissues by n-heptane and estimated by gas-chromatography using an electron capture detector unit. Variation in halothane concentrations between adjacent pieces of tissue was found. The 95% confidence limits of a single estimation was +/- 10.8% of the mean for liver and +/- 6.1% for the muscle in pigs. The corresponding figures in rats were +/- 9.5% and +/- 3.0%.