γ-Al_2O_3-氧化石墨烯吸附材料用于尿液中核苷的检测

γ-Al_2O_3-graphene oxide absorbent material for detection of nucleosides in urine

用γ-Al_2O_3纳米粒子键合的氧化石墨烯(GO)作为固相萃取吸附剂,与高效液相色谱法联用,建立了一种对人体尿液中4种核苷分离测定的新方法。采用透射电镜(TEM)、热重分析(TGA)及傅里叶红外光谱(FT-IR)对吸附剂进行表征。考察了洗脱液种类、吸附剂用量、样品体积及样品pH值对吸附性能的影响,通过平衡吸附量衡量吸附效果。在最佳萃取条件下,该吸附剂对核苷具有一定的富集能力。胞苷、肌苷、鸟苷在0. 10～10 mg/L,尿苷在0. 05～10 m g/L范围内呈现良好的线性关系,线性相关系数为0. 996 7～0. 997 3,检出限为0. 010～0. 021 m g/L,日内和日间相对标准偏差分别为0. 1%～0. 8%和1. 0%～3. 1%。实际尿样中,4种核苷的加标回收率为71. 3%～107. 4%,相对标准偏差(n=3)小于4. 8%。该方法灵敏度高、精密度和回收率良好,可用于尿液样品中核苷类物质的富集和测定。

γ-Al2O3 nanoparticle-bonded graphene oxide(γ-Al2O3-GO)was prepared for use as a solid phase extraction absorbent and for preconcentration of four nucleosides in human urine samples for investigation by high-performance liquid chromatography(HPLC).Transmission electron microscopy(TEM),thermal gravimetric analysis(TGA),and Fourier transform infrared spectroscopy(FT-IR)were employed to characterize the absorbent.Several parameters(eluent species,absorbent amount,sample volume,and sample pH)were optimized,and the absorption efficiency was determined based on equilibrium absorbent amounts.Under optimal conditions,theγ-Al2O3-GO absorbent displayed enhanced absorbent ability for nucleosides.The calibration curve showed good linearities in the range of 0.10-10 mg/L for cytidine,inosine,and guanosine,and 0.05-10 mg/L for uridine;the correlation coefficient was observed to be in the range of 0.996 7-0.997 3.The limits of detection for the four nucleosides were in the range of 0.010-0.021 mg/L.Intra-day and inter-day relative standard deviations were 0.1%-0.8%and 1.0%-3.1%,respectively.The recoveries of the four nucleosides in urine samples ranged from 71.3%to 107.4%,and the relative standard deviations(n=3)were less than 4.8%.The results demonstrated that the proposed method is faster,more sensitive,and more efficient.Therefore,solid phase extraction(SPE)-basedγ-Al2O3-GO can be considered more suitable for the determination and enrichment of nucleosides in urine samples.