Simplified detection of quaternary ammonium compounds by gas chromatography

An analytical method for the measurement of quaternary ammonium compounds in biological fluids has been developed. Samples are prepared by forming the corresponding iodides, which are extracted and isolated. The residue is taken into n-hexane or into water and part of the solution obtained is injected onto the gas chromatograph where thermal degradation takes place. The methyl iodide released is measured by a 63Ni electron capture detector. This method is quite sensitive and detects with good reliability and reproducibility as little as 10(-14) mole quaternary ammonium compound.