chromatographic (GC) analysis in a simple and inexpensive apparatus involving very little
solvent consumption. A small drop (8 μL) of a water-immiscible organic solvent, containing
an internal standard, is located at the end of a Teflon rod which is immersed in a stirred
aqueous sample solution. After the solution has been stirred for a prescribed period of time,
the probe is withdrawn from the aqueous solution, and the organic phase is sampled with a …