Studies On The Determination Of Perfluorooctanoic Acid (PFOA) And Perfluorooctane Sulfonate (PFOS) In The Waterborne Coating And The Toy Plastic Materials By UPLC-MS/MS

Perfluorooctanoic acid and perfluorooctane sulfonate are new kinds of persistent organicpollutants. And them have been paid much attention to, because of their biological toxicity, highbio－accumulation capacity and stable physical and chemical properties. This paper aims toestablish a efficient and accurate procedure for the determination of perfluorooctanoic acid andperfluorooctane sulfonate in the waterborne coatings and the toy plastic. The main results andconclusions are summarized as follows:(1) Detection conditions of PFOA&PFOS and standard curveBased on the comparison with the advantages and disadvantages of other analyticalinstruments, UPLC－MS/MS was chosen to determine the trace amount of PFOA and PFOS,with negative electrospray ionization and multiple reaction monitoring (MRM) mode. And theconditions parameters of UPLC－MS/MS was optimized to achieve good results.The linear correlation ratio was good (R2=0.9999) at the linear range of2~200μg/L, therelative standard deviations (RSD) of PFOA and PFOS were0.30~6.24%and0.26~3.03%,respectively.Matrical standard curve was used to minimize matrix effect on the waterborne coating. Thelinear correlation ratios of PFOA and PFOS were R2(PFOA)=0.9967and R2(PFOS)=0.9946;recoveries were91.29~100.08%and88.47~103.89%, respectively.(2) Sample pretreatmentStudied about the procedure of sample extraction, the data revealed that the soxhletextraction was selected for the Waterborne Coating with acetonitrile as optimum extractionsolvent, and the recoveries were23.0%and92.5%for PFOA and PFOS, respectively. From theresults we could find that the microwave extraction was selected for the Toy PlasticMaterials(PVC) with ethyl acetate as optimum extraction solvent, and the recoveries were44%and88%for PFOA and PFOS, respectively.(3) Purification of extract solutionConsidering the stability of the test results and the maintenance of testing equipment,extract solution was needed to purify before quantification. The results show that the compositenon－polar weak－anionic extraction column WAX from Waters company was chosen, with therecoveries of standard diluent of PFOA and PFOS were94%,91%, respectively.(4) Detection limit and recoveryCalculated in three times of ratio of signal to noise, detection limit could be speculated lessthan1ng/mL. While the quantify detection limit under2.6496ng/mL(S/N≥10.5)，2.6624ng/mL (S/N≥19.5) for PFOA and PFOS, respectively.The recoveries of the waterborne coatings spiked sample were21.99~21.32%,82.78~92.54%for PFOA and PFOS, respectively. The recoveries of toy plastic materials spikedsample were41.87~46.18%,88.08~89.19%for PFOA and PFOS, respectively.An analytical method based on ultra－high performance liquid chromatography tandemmass spectrometry was developed for analysis of PFOA and PFOS in the waterborne coating andthe toy Plastic materials. The method not only meets EU regulations on PFOS, but also has thecharacteristic of directly detected, efficient and accurate. The determination of PFOA wasaccurate and reliable in quality, but the recovery was comparative low, which could not reach thetesting requirements. So the study of PFOA needs for further improvements.