Study On Extraction And Determination Methods Of Nanoparticle Fe And Ti In Coastal Seawater

This paper mainly study the extraction technology and determination methods of nanoparticle Fe and Ti in coastal seawater.Firstly,with Minimate TFF Capsule w/1Kd Omega system,we detected the function of cross-flow system and corrected the ultrafiltration membrane pore size.Then for determining the ultrafiltration process,we selected the best cleaning process,optimized the concentration factor.Secondly,with flow-injection system,we used Toyopearl AF 650M resin to fill the column,optimized the best experimental conditions.Finally,we took Fotan Bay and Jiulong River as demonstration area,and extracted and determined the nanoparticle Fe and Ti.Study results are as follows:(1)The initial normalized water permeability of ultrafiltration membrane is 1.6 ultrafiltration membrane with 10 psi transmembrane pressure.The integrity and membrane recovery of ultrafiltration membrane keeping good along the experimentation.The calibration result of ultrafiltration membrane pore size is 39.0 kDa?56.5 kDa,and has a great difference with the 1 kDa marked by the manufacturer.(2)The cleaning methods of cross-flow system is 0.1 mol/L NaOH and 0.1 mol/L HCl wash the system and circulate 30 minutes and then wash to neutral by ultra-pure water.The concentration factor is defined less than 4.(3)We used Toyopearl AF 650M resin to fill the column.The best experimental conditions of flow-injection system is:1 mL/min flow rate of injection,1 mL/min flow rate of elution,0.8 mol/L HNO3 as elution solution,buffer solution pH 5.5.And seawater sample need 120 W UV-oxidation 90 min.(4)The detection limit(MDL)of the method determination Fe and Ti in seawater are respectively:0.057 ?g/L,0.007 ?g/L,The precision of Fe and Ti is 6.8%and 8.8%respectively.The recovery rates of standard addition experiment of Fe and Ti are respectively:96.1%?118.8%,87.3%?106.4%.(5)The recovery of Fe and Ti is 70.3%?111.2%,80.2%?99.2%respectively in Fotan Bay.The recovery of Fe and Ti is 69.6%?99.7%,66.3%?110.8%respectively in Jiulongjiang River.Indicate the cross-flow system can achieve mass balance of Fe and Ti.(6)The concentration of dissolved Fe in Fotan Bay is 0.262 ?g/L?0.451?g/L,average value is 0.335 ?g/L,and The concentration of nanoparticle Fe(NFe)in Fotan Bay is 0.022 ?g/L?0.092 ?g/L.The percentage of NFe in dissolved Fe is 5.8%?26.8%,The concentration of nanoparticle Ti is 0.000 ?g/L?0.003 pg/L,and it's percentage in dissolved Ti is 0.8%?5.7%.means soluble Fe and is in the majority in Fotan Bay.(7)In Jiulong River,the concentration of dissolved Fe and Ti(?0.8 ?m)are 0.493?g/L-29.865 ?g/L,0.026 ?g/L?0.107 ?g/L respectively,and the concentration of NFe and NTi are 0.082 ?g/L?20.157 ?g/L,0.002 ?g/L?0.051 ?g/L respectively,their percentage in total dissolved Fe or Ti are bath reduce with the increase of salinity.