【摘要】 以石墨烯/二氧化钛复合材料为吸附剂,结合石墨炉原子吸收光谱法,建立了Pb?和Cd?的检测方法。优化的实验条件为:溶液pH=5.0,吸附时间为60 min,吸附剂用量为0.02 g。结果表明:吸附过程符合拟二级动力学反应模型;吸附反应是吸热过程。建立的石墨烯/二氧化钛复合材料富集-石墨炉原子吸收光谱法对Pb2+和Cd2+的检出限分别为0.086和0.006μg/L,相对标准偏差为3.2%和2.5%。将本方法应用于矿石标准样品的测定,测定结果与标准值相符;用于茶叶实际样品的测定,回收率为96.8%~105.0%。更多还原

【Abstract】 A method for the determination of lead and cadmium was developed with graphene-TiO2 composites(GN-TiO2) as adsorbents combined with graphite furnace atomic absorption spectrometry.Effects of various experimental conditions on the adsorption capacity were investigated.The optimized conditions were: sample pH as 5.0,contact time as 60 min,and adsorbent dosage as 0.02 g.Results showed that the processes could be simulated by a pseudo-second-order model.The adsorption process was proved to be an endothermic one.LODs of lead and cadmium of the developed method were calculated as 0.086 μg/L and 0.006 μg/L with RSDs of 3.2% and 2.5%,respectively.Furthermore,the present method was applied to the determination of lead and cadmium in different reference materials and real tea samples with satisfactory results.更多还原