The determination of a volatile gas, vinylidene fluoride, in blood during a nose-only exposure.
A method has been developed for measuring the volatile gas vinylidene fluoride (VDF) in the blood of rats during nose-only exposure. Blood was sampled via a jugular cannula constructed from silastic tubing. The silastic cannula was sutured and glued to the vein and was passed subcutaneously to the back of the rat's neck, where it was externalized and anchored in the same manner. Securing the cannula at these two sites stabilized its position in the vein. A strip of Velcro sutured to the skin of the animal's back served to protect and store the external part of the cannula. VDF in blood was measured by headspace sampling and gas chromatography. The gas chromatography was equipped with a packed column and a flame ionization detector. The method requires 250 microL of blood and has a detection limit of 6 ng/mL of VDF in blood (S/N: 3 X 1). Vinylidene fluoride in the blood reached equilibrium with the headspace within 1.5 h and was stable for up to 4.0 h. The relative standard deviation for blood levels determined under experimental conditions was less than 15%. The interday reproducibility of the standard curve was +/- 3.5%.