ION MOBILITY SPECTROMETRY AS FLOW-INJECTION DETECTOR AND CONTINUOUS-FLOW MONITOR FOR ANILINE IN HEXANE AND WATER

Ion mobility spectrometry (IMS) was used as a flow-injection detector to quantitatively examine the ionization chemistry of aniline in hexane. A 5-mu-l sample was vaporized at 15-90-sec intervals in a flowing air stream and analyzed with an IMS equipped with acetone reactant ion chemistry, ambient temperature drift tube and membrane-based inlet. Precision was 3-11% relative standard deviation for 1-100 ppm aniline in hexane with 90-sec injection intervals and detection limits were ca. 0.5 ppm with 5-mu-l injections. Matrix effects with amine and organic solvent mixtures were observed and corrected for low and medium proton affinity interferences with standard addition methods. Pronounced fouling of the IMS occurred when a continuous water flow was introduced for aqueous flow injection-IMS. Continuous water monitoring without degraded IMS performance was possible by sampling air flow through a Silastic tube immersed in an aqueous sample.