Soxhlet-Assisted Matrix Solid Phase Dispersion for the quantitative analysis of 2-Ethylhexan-1-ol

Abstract

Background/Objectives: 2-Ethylhexan-1-ol (2-EHN) is a fatty alcohol, an organic compound used as a frother during the production of ground calcium carbonate (GCC) to remove impurities. Methods/Statistical analysis: Matrix solid-phase dispersion (MSPD) using XAD-4 (a non-polar polystyrene resin) was applied to adsorb and concentrate 2-EHN followed by Soxhlet extraction that extract 2-EHN (having a limited solubility for water) by the continuous extraction with recycling the solvent (ethyl acetate).The mass spectral ions of 2-EHN (acquired by GC-MS), m/z 57, 70, 83, 98, and 112 were accessed for the most accurate quantification. Findings: Findings: The amount of 2-EHN adsorbed to XAD-4 resin (1 g) was highest after stirring for 14 hours followed by continuous extraction with 80 mL of ethyl acetate for 3 hours at 90?C. A modified Soxhlet extractor with a glass thimble (having a small hole at the bottom) worked well. The most accurate results were given by the ions at m/z 83 and 98 with 126% each (the value closest to 100%). These may be the most desirable mass spectral ions for the quantitation of 2-EHN because of the lack of background noise. The calibration function was linear with a correlation coefficient of 0.9944. The limit of quantitation was measured as 0.5µg/L. The established 2-EHN analysis method was successfully applied to real surface water sampled far from and close to aground calcium carbonate (GCC) quarry, where the resulting levels of 2-EHN were shown to be 3.0 and 6.8µg/L, respectively. Improvements/Applications: 2-EHN in environmental surface water was accurately quantified by GC-MS analysis using m/z 83 or m/z 98 after sample treatment by adsorption to Amberite XAD-4 and continuous Soxhlet extraction with ethyl acetate enabling ppb level quantitation.