Functionalized Material Used In Sample Pre-treatment Technology For HPLC Analysis

Chromatographic analysis is the most important field in analytical chemistry,which has been widely applied in medicine, environment control, life science, andpetrochemical research. In the analytical process, the sample matrices are mostlycomplicated, and the analytes are with low concentration in the environment. Thus, inorder to avoid the interference, improve the sensitivity, insure the accuracy of theresults, the sample pre-treatment becomes of great importance. With the advances ofscience, especially for the instrument and analytical technology, sample pre-treatmenthas addressed tremendous attentions of scientists. In order to develop simple, quickand environmentally-friendly method, we have carried out the following works.1. Isoquinoline-functionalized magnetic microspheres were synthesized in athree-stage system and characterized by Fourier transform infrared （FT-IR） spectraand scanning electron microscopy （SEM）. The prepared material was used for thepreconcentration of three perfluorinated compounds （PFCs） in water combinedwith high-performance liquid chromatography coupled with mass spectrometry（HPLC-MS）. Several factors that may affect the extraction efficiency such aseluent and its volume, amount of sorbents and standing time were optimized.Under the optimal conditions, satisfactory recoveries （77.79-85.27％） wereachieved with relative standard deviations （RSDs） less than5.0%. The limits ofdetection for perfluoroheptanoic acid （PFHpA）, perfluorooctanoic acid （PFOA）and perfluorooctanes sulfonate （PFOS） were20.00,15.00and5.30ng L-1,respectively. The results indicated that the isoquinoline-functionalized magneticmicrospheres are with significant promise for the analysis of PFCs inenvironmental samples.2. Triphenylamine （TPA）-functionalized magnetic microspheres （Fe₃O₄/SiO₂/TPA）were prepared and applied as solid phase extraction （SPE） adsorbents for theanalysis of polycyclic aromatic hydrocarbons （PAHs） in environmental samples incombination with high-performance liquid chromatography （HPLC）. The magneticsolid-phase extraction （MSPE） conditions affecting the extraction efficiency wereoptimized, including elution solvent, standing time, amount of sorbents, and saltconcentration. Due to the strong Ï€-Ï€ conjugate effect between the benzene rings ofTPA and PAHs, high extraction efficiency was achieved with spiked recoveries of 80.21–108.33%and relative standard deviations （RSDs） of less than10%. Goodlinearities （R2>0.999） for all calibration curves were obtained with low limits ofdetection （LOD） of0.25,0.5,0.5,3.75,0.2and0.04ng/L for anthracene,fluoranthene, pyrene, chrysene, benzo（b）fluoranthene and benzo（k）fluoranthene,respectively. The achieved results indicate the applicability of Fe₃O₄/SiO₂/TPA asMSPE adsorbents.3. After investigation on the sample of pollutants, a sample preparation method hasbeen developed to remove pollutants from the sample by filtration, solid phaseextraction and dilution. Using gradient elution, all of seven anions have beenseparated in one injection. The linear range of this method was0.01-0.5mmol/Land the limits of determination （LODs） were lower than0.2mg/L, the relativestandard deviation （RSD） of the method in peak area was1.11%to3.79%.