Solid-phase extraction based on amino-functionalized graphene oxide nanocomposites for analysis of short-chain perfluorinated alkyl acids in human serum by ion chromatography mass spectrometry

A highly sensitive method was developed for the analysis of short-chain perfluorinated alkyl acids (PFAAs) in serum samples using solid-phase extraction (SPE) coupled with ion chromatography-electrospray ionization-mass spectrometry. The synthesized amino-functionalized graphene oxide nanocomposites were used as an SPE sorbent for the enrichment of trace analytes and purification of samples. They exhibited high selectivity to polar compounds. The suppressor was employed to remove counterions and reduce background signals of mobile phase. These two crucial steps could effectively eliminate matrix effects and enhance analytical sensitivity. The lowest limits of quantification were 2.0 μg L^-1 for perfluorobutanoic acid and perfluorovaleric acid, 1.0 μg L^-1 for perfluorocaproic acid and 0.50 μg L^-1 for perfluorobutane sulfonic acid, respectively. The procedure was successfully applied for determination of trace PFAAs in 25 serum samples. Mean recoveries ranged from 86.3 to 101.4% with relative standard deviations of 1.6-6.8%. The method allowed an excellent separation and quantification of short-chain PFAAs that were difficult to analyze by conventional chromatography.