Rapid on-line microextraction method for the analysis of glyphosate in soy and pepper based on fiber-spray/mass spectrometry

We report on the design and testing of a rapid, on-line microextraction kit based on fiber-spray/mass spectrometry. The kit consists of a section of a porous-polypropylene hollow fiber, a serum bottle, a seal cap with a gasket and an electromagnetic stirrer. The kit is placed between the mass inlet and the ESI needle. Using this configuration, glyphosate can be extracted from a very dilute solution and then evaporates and escapes from the fiber surface. When glyphosate molecules make contact with the ESI plume, which arises from the ESI needle tip, they are ionized and then detected by a mass spectrometer. Using the setup, it was possible to improve the limit of detection for glyphosate after microextraction by ∼1000-fold, resulting in a limit of detection of 10 ppb.