Study On Solid Phase Extraction Of Cu²⁺ And Mn²⁺ And Determination Of Nano Hydroxyapatite Composites

Heavy metals copper and manganese are essential trace elements needed by human body,but also a kind of non-degradable toxic pollutants.Due to the long-term accumulation of heavy metals discharged into the environment,it will cause serious impact on human health.Therefore,it is of great significance to establish a relatively economical and effective method for the determination of trace heavy metals in environmental samples.Firstly,in order to establish an economical and effective method for the detection of heavy metals Cu2+ and Mn2+,we prepared a novel ternary composite using three materials,namely nano-hydroxyapatite,silica gel and Twain 80,with silica gel as the support.The composites were characterized by transmission electron microscopy,scanning electron microscopy,X-ray diffraction,BET and infrared spectroscopy.At the same time,the preparation conditions of the composites were optimized.The selectivity of Cu2+ and Mn2+ for 8 divalent metal ions was studied by using this composite.Therefore,the solid-phase extraction of Cu2+ and Mn2+ for nano-hydroxyapatite composite was established.Secondly,copper is a non-ferrous metal closely related to the ecosystem,which is essential for plant photosynthesis and human metabolism.Both insufficient and excess copper content will have adverse effects on organisms.Therefore,solid-phase extraction of Cu2+ with this material was studied to explore the best conditions for solidphase extraction,and the absorbance signal was detected by flame atomic absorption.The dynamic adsorption model for Cu2+ adsorption by nano-hydroxyapatite composites was studied.The method was applied to the determination of copper in GBW10011 wheat and GBW10043 rice,and the determined value was basically the same as the standard value.It is used for the determination of copper content in actual environmental water samples and food with the recovery of 97.78~103.73 %.Finally,the solid phase extraction of Mn2+ with this material was studied.The flame atomic absorption was used to detect the absorbance signal and explore the best condition of solid phase extraction.The dynamic adsorption model of nanohydroxyapatite composite for the adsorption of Mn2+ was studied.The method was applied to the determination of manganese in GBW10011 wheat and GBW10043 rice,and the measured values were basically consistent with the standard values.It is used for the determination of manganese content in actual environmental water samples and food with the recovery of 95.50~102.60 %.