Flow Injection Analysis Technique for Online Preconcentration of Lead Ions in Airborne Particulate Matter Using Imprinted Polymer as the Sorbent

This work reported a simple and sensitive flow injection analysis(FIA) technique coupled with a Flame Atomic Absorption Spectrophotometer(FAAS) for online preconcentration of lead(Ⅱ) ions in the airborne particulate matter samples(PM2.5)using ion-imprinted polymers as adsorbent packed in minicolumn.A bulk polymerization method was chosen to synthesize the polymer based on a ternary complex of lead ions with 4-2-pyridilazo resorcinol and 4-vinyl pyridine with methacrylic acid as a functional monomer.The optimum pH for sorption was 6,and other variables for the FIA system were optimized,including breakthrough volume,eluent concentration,and eluent volume.The optimum conditions were reached with a breakthrough volume of 4.45 mL,calculated as a dynamic retention capacity of 5.20 mg/g of Pb(II) 40 mg/L,with a 1.5 mL/min flow rate.The eluent used for the FIA system was 0.5 mL HNO3of 3 mol/L.Linearity,precision,and limits of detection of the FIA system were determined before being applied to preconcentration and analysis of lead ions in PM2.5samples.The precision of the method was determined to be 3.09% by calculating the coefficients of the variant.Linearity of the method in the concentration range of 50-1000 μg/L gave a coefficient correlation of 0.9925,showing a good response,and the limit of detection of the system was 5.11 μg/L,better than that of the FAAS method.Performances of the FIA system were evaluated and showed good results with an enrichment factor of more than 20 times higher and a concentration efficiency of 11.65 min-1 with a consumptive index of 4.5 mL.Preconcentration and analysis of the PM2.5 samples in Bandung City showed the concentrations of Pb(II) were 26.67 μg/L and 33.3 μg/L with the accuracy of the method for each sample of104.75% and 107.86%.