Rapid Determination of Residues of 6 Pollutants in Soil around Rubber Products Industrial Park by Ion Chromatography-Mass Spectrometry

A method for rapid determination of residues of 6 pollutants including butyl xanthan acid, dichloroacetic acid, trichloroacetic acid, gallic acid, tartaric acid, and p-coumaric acid in soil around rubber products industrial park by ion chromatography-mass spectrometry (IC-MS) was proposed. 10 g of the dried and sieved soil sample was taken, and placed in the extraction tank. 20 g of diatomite was added, and the mixture was extracted with a mixed solution of methanol and acetone at a volume ratio of 2∶1 by accelerated solvent extraction. The extract was passed through a 0.22 μm polyether sulfone filter membrane, in which 6 pollutants were determined by IC-MS. DIONEX Ion-Pac AS17 chromatographic column was used as the stationary phase, and 0.1 mol·L⁻¹ potassium hydroxide solution was used as the rinsing solvent to separate the 6 pollutants. Electrospray ion (ESI) source was used for mass spectrometry. The targets were detected by multiple reaction monitoring (MRM) mode in negative ion (ESI⁻) scanning mode. As shown by the results, linear relationships between the corresponding peak areas and mass concentrations of 6 pollutants were found within 0.005-5.0 mg·L⁻¹, with detection limits (3S/N) in the range of 0.009-0.023 μg·L⁻¹. Test for recovery was made by the standard addition method, giving results in the range of 83.8%-95.1%, with RSDs (n=6) of the determined values less than 5.0%. This method was used to determine the residues of 6 pollutants in actual soil samples around rubber products industrial park, tartaric acid was not detected, and the detected amounts of the other pollutants were in the range of 13.04-61.25 µg·L⁻¹.