| Polycyclic aromatic hydrocarbons are popular carcinogen for mammals, which derived from combustion of organic matrices. Exposure to these environmental contaminants and their potential damage to public health has become a worldwide concern. It is urgent to find a way to evaluate human exposure to PAHs. The metabolite of PAHs in urine (OH-PAHs) could be used as the biomarkers of exposure to PAHs. The monohydroxy polycyclic aromatic hydrocarbons level in human urine can provide useful information for environment exposure to polycyclic aromatic hydrocarbon.A new magnetic solid-phase extraction method (MSPE) based on magnetic nanoparticles (MNPs) was developed and had received increasing interests in recent years. MNPs have high extraction efficiency because of the high surface area-to-volume ratio compared with other adsorbents. They exhibit the advantage of rapid separation from matrix due to the excellent magnetic response. Besides the superiormagnetic response, many researches focused on the surface modifications of MNPs to improve their binding capacity and extraction efficiency.In this paper, two magnetic solid-phase extraction-liquid chromatography-mass spectrometry (MSPE-LC-MS) methods were established. One was off-line MSPE-LC-MS, the other one was on-line MSPE-LC-MS. Two different magnetic materials were prepared. The target analytes of two method were both OH-PAHs in urine. Details are as follows:(1) Novel Fe3O4/graphene oxide composites were prepared and their application in magnetic solid phase extraction of monohydroxy polycyclic aromatic hydrocarbons in urine was investigated by coupling to liquid chromatography-mass spectrometry. In the hybrid material, Fe3O4 nanoparticles provide strong magnetic response property to simplify the analytical procedure and graphene oxide provide large functional surface for the adsorption. At optimum condition, the linear correlation coefficients of 2-naphthol, 3-hydroxyphenanthrene,1-hydroxypyrene were all above 0.99, the limits of detection (LOD) were from 0.01 to 0.15 ng mL-1, the relative standard deviation (RSD) were between 6.8-15.5%. The recoveries were between 98.3-125.2%. This proposed method was applied for the determination of three OH-PAHs in the urine of no-smoking men, who aged 18-20 (n=38) and lived in two cities with different environment (Wuhan, Enshi). The results indicated that the urinary level of OH-PAHs could reflect the pollution level and the proposed method has the potential to determine pollutants and their metabolites in human urine.(2) Multi-functional magneticnano-adsorbent (TW/CM-β-CD/Fe3O4 MNPs) was fabricated by the surface modification of Fe3O4 nanoparticles (MNP) with carboxymethyl-β-cyclodextrin (CM-β-CD) and the surfactant TW20. The morphology and composition were characterized via x-ray diffraction and scanning electron microscopy. The specific surface area and selectivity of the prepared materials were also investigated. The result showed they exhibited good selectivity and large adsorption efficiency. Based on this material, a simple analysis of polycyclic aromatic hydrocarbon metabolites in urine was studied by on-line coupling MSPE to liquid chromatography-mass spectrometry. At optimum condition, the linear correlation coefficients of three targets were all above 0.99, the LOD were from 0.005 to 0.018 ng mL-1, the relative standard deviation were between 1.8-14.7%. The proposed method possesses the numerous advantages, including high automatization, good selectivity and excellent sensitivity. |
PDF Full Text Request