Patent ID: 9128106
Filing Date: 2015-09-08
Classification: G01N

Abstract:
1. A dispersive liquid-liquid microextraction method of detecting N-nitrosoamines, comprising the steps of: adding microliters of an extraction solvent, the extraction solvent being xylene, and microliters of a disperser solvent, the disperser solvent being methanol, to microliters of an aqueous solution to form a test sample; agitating the test sample at an agitation speed of 706.15 RPM to form a cloudy suspension when an analyte is present in the test sample; allowing the test sample to separate into an organic phase and an aqueous phase; withdrawing an aliquot of the organic phase from the test sample with an extraction time of 25.77 minutes; directly injecting the aliquot into a gas chromatograph coupled with a mass spectrometer; and analyzing the aliquot by gas chromatography and mass spectrography for the presence of N-nitrosamines, wherein the steps of adding the microliters of the extraction solvent and the microliters of the disperser solvent, agitating the test sample, withdrawing the aliquot and directly injecting the aliquot are each performed by a programmable array logic auto-sampler.