ABSTRACT
A diatomite supported graphene oxide composite (GO@Dt-NH2) was fabricated and explored as a solid-phase extraction adsorbent coupled with high performance liquid chromatography to determine the trace hydroxyl polycyclic aromatic hydrocarbons (2-hydroxy-naphthalene, 2-hydroxy-fluorene, 1-hydroxy-phenanthrene, and 1-hydroxy-pyrene) in urine samples. The fabricated composites were characterized by X-ray powder diffractometry and scanning electron microscopy. GO@Dt-NH2 offered enhanced adsorption affinity towards the analytes compared with the bare diatomite. The amount of graphene oxide and the factors affecting solid-phase extraction were investigated in detail. Under the optimized conditions, the method gave good linearity (0.30-200 ng/mL) and a low detection limit (0.10-0.15 ng/mL) for the hydroxyl polycyclic aromatic hydrocarbons. The average recovery for spiked urine samples with three levels ranged from 90.6% to 100%. The intra-day and inter-day relative standard deviations were in the range of 1.8-6.4% and 2.7-11.8%, respectively. Besides, the GO@Dt-NH2 provided enrichment factors of 18-20 and superior purification ability. The developed method was successfully applied to the determination of hydroxyl polycyclic aromatic hydrocarbons in urine samples from smoking volunteers.
Subject(s)
Diatomaceous Earth/chemistry , Graphite/chemistry , Hydrocarbons/chemistry , Polycyclic Aromatic Hydrocarbons/chemistry , Solid Phase Extraction , Chromatography, High Pressure Liquid , Humans , Limit of Detection , Molecular Structure , Polycyclic Aromatic Hydrocarbons/isolation & purification , Solid Phase Extraction/methodsABSTRACT
A method based on the magnetic solid-phase extraction using magnetic carbon nitride composites coupled with high performance liquid chromatography-fluorescence detector (HPLC-FLD) was developed for the simultaneous determination of three hydroxyl polycyclic aromatic hydrocarbons (OH-PAHs) in urine. The synthesized sorbent was characterized by scanning electron microscope, X-ray diffractometer, vibrating sample magnetometer and surface area analyzer. The extraction parameters such as amount of sorbent, extraction time, eluting solvent and volume (single eluting volume×eluting times) were investigated in detail. Under the optimized conditions, the method showed a linear range of 0.25-250 µg/L (correlation coefficient=0.999). The limit of detection was 0.08 µg/L and the limit of quantification was 0.25 µg/L for each analyte. The proposed method gave a recovery of 90.1%-102%. The relative standard deviations for the intra-day and inter-day were 1.5%-7.7% and 2.2%-8.7%, respectively. The feasibility of the developed method was further demonstrated during the analysis of real samples. The results indicate that the magnetic carbon nitride composites can be used for the effective purification and enrichment of three OH-PAHs in urine. In addition, the method can be applied for analysis of urinary OH-PAHs in a simple, fast, and effective manner.
