Anupreet Kaur

A review on applications of nanoparticles for the preconcentration of environmental pollutants

Advances in nanoscale science and engineering suggest that many of the current problems involving water quality could be resolved or greatly improved using nanoparticles. Currently, the most widely used method for the removal and separation of toxic metal ions/organic compounds is the solid phase extraction technique. Recently, there have been reports in the literature on the enrichment and separation of trace elements and organic compound in the sample solutions by means of nanoparticles like TiO2, Al2O3, ZrO2, MnO and CeO2. Nanoparticles have unique properties like large specific surface area, high adsorption capacity and low temperature modification, so they are promising solid-phase extractants and have contaminant scavenging mechanisms. This feature article includes research work concerned with preparation, characterization and application of nanoparticles in preconcentration, separation and determination of trace pollutants from various environmental samples.

A Preconcentration Procedure Using 1-(2-Pyridylazo)-2-napthol Anchored to Silica Nanoparticle for the Analysis of Cadmium in Different Samples

A new analytical method using 1-(2-pyridylazo)-2-naphthol modified SiO2 nanoparticles as solid-phase extractant has been developed for the preconcentration of trace amounts of Cd(II) in different water samples. Conditions of the analysis such as preconcentration factor, effect of pH, sample volume, shaking time, elution conditions and effects of interfering ions for the recovery of analyte were investigated. The adsorption capacity of nanometer SiO2-PAN was found to be 60.57 μmol/g at optimum pH and the detection limit (3σ) was 0.76 μg/L. The extractant showed rapid kinetic sorption. The adsorption equilibrium of Cd(II) on nanometer SiO2-PAN was achieved just in 15 minutes. Adsorbed Cd(II) was easily eluted with 6 mL of 6 M hydrochloric acid. The maximum preconcentration factor was 50. The method was applied for the determination of trace amounts of Cd(II) in various synthetic samples and water samples.

PRECONCENTRATION OF Cd2+ IN DIFFERENT SAMPLES BY CHEMICALLY MODIFIED SIO2-DHAQ NANOPARTICLES

ABSTRACT A new analytical method using 1,8-dihydroxyanthraquinone modified SiO 2 nanoparticles as solid-phase extractant has been developed for the preconcentration of trace amounts of Cd 2+ in different samples. Conditions of the analysis such as preconcentration factor, effect of pH, sample volume, shaking time, elution conditions and effects of interfering ions for the recovery of analyte were investigated. The adsorption capacity of nanometer SiO 2 -DHAQ was found to be 85.83µmol/g at optimum pH and the detection limit (3σ) was 0.60ng/mL. The extractant showed rapid kinetic sorption. The adsorption equilibrium of Cd 2+ on nanometer SiO 2 -DHAQ was achieved within 20 min. Adsorbed Cd 2+ was easily eluted with 6mL of 1M hydrochloric acid. The maximum preconcentration factor has been found to be 66.70. The method was applied for the determination of trace amounts of Cd 2+ in different samples. Keywords : Chemically modified SiO 2 -nanoparticles, 1,8-dihydroxyanthraquinone, Preconcentration, Separation.

Sorption and Preconcentration of Lead on Silica Nanoparticles Modified with Resacetophenone

The silica-resacetophenone (SiO2-RATP) nanoparticles were used as a new sorbent for extraction of trace amounts of Pb(II) by batch technique. Conditions of the analysis such as preconcentration factor, effect of pH, sample volume, shaking time, elution conditions and effects of interfering ions for the recovery of analyte were investigated. The adsorption capacity of nanometer SiO2-RATP was found to be 167.24 µ mol/g at optimum pH and the detection limit (3σ) was 0.58 µg/L. The adsorption equilibrium of Pb(II) on nanometer SiO2-RATP was achieved in 20 min. Adsorbed Pb(II) was easily eluted with 5 mL of 0.5 M hydrochloric acid. The maximum preconcentration factor was 60. The method was applied for the determination of trace amounts of Pb(II) in various natural water rivers.

Preparation of Silica-PAN Functionalized Nanoextractants for the Extraction of Ferbam from Various Samples

1-(2-pyridylazo)-2-naphthol modified SiO2 nanoparticles were synthesized and evaluated as a nanoadsorbent for removing Ferbam from various environmental sources and fortified grain and vegetables samples. The 1-(2-pyridylazo)-2-naphthol modified SiO2 nanoparticles were prepared by the sol-gel method. Nanoparticles were characterized by SEM and FT-IR. The adsorption of Ferbam was examined by the batch equilibrium technique. Conditions of the analysis such as preconcentration factor, effect of pH, sample volume, shaking time, elution conditions, and effects of interfering ions for the recovery of analyte were investigated. The equilibrium data analyzed by using the Langmuir isotherm, and the Freundlich and Temkin isotherm models, showed better agreement with the former model. The adsorption capacity of nanometer SiO2-1-(2-pyridylazo)-2-naphthol was found to be 50.70 μmol/g at optimum pH and the detection limit (3σ) was 0.40 μg/L. The extractant showed rapid kinetic sorption. The adsorption equilibrium of Ferbam on nanometer SiO2-1-(2-pyridylazo)-2-naphthol was achieved in 10 mins. Adsorbed Ferbam was easily eluted with 6 mL of 6 M hydrochloric acid. The maximum preconcentration factor was 58.33. The method was applied for the determination of trace amounts of Ferbam in various water samples and fortified samples.