On-Line Flow Injection Preconcentration of Palladium in Environmental Waters Using a Microcolumn Packed with Silica Nanoparticles Modified by γ-Aminopropyltriethoxisilane and Determination by Flame Atomic Absorption Spectrometry

Abstract

A novel solid phase sorbent with silica nanoparticles modified by γ-aminopropyltriethoxysilane (modified nanometer SiO₂-γ-APS) was employed for the separation and preconcentration of palladium(II) before determination by flame atomic absorption spectrometry. The analytical conditions including pH, the eluent, and flow rates were optimized. Trace palladium(II) was quantitatively absorbed on a microcolumn of the sorbent at pH 5.0. The enrichment factor and sampling frequency were 45 and 12 h⁻¹, respectively. Palladium(II) adsorbed on microcolumn was eluted quantitatively with 9% KSCN solution; the eluent solution was introduced into a flame atomic absorption spectrophotometer. The detection limit for palladium was 2.48 µ gL⁻¹ and the relative standard deviation (RSD) was 1.8% (n = 11) at the 0.1 mg L⁻¹ palladium level. The recoveries of palladium were 95.0% to 100.3%. The proposed method was successfully applied to the determination of palladium in pond and river water samples.

Keywords:

• Environmental water
• Flow injection
• Palladium
• Preconcentration
• Silica nanoparticle

Notes

LOD: limit of detection; RSD: relative standard deviation; EF: enhancement factor; SV: sample volume; FAAS: flame atomic absorption spectrometry; ICP-AES: inductively coupled plasma mass spectrometry; SF-FIS: selective stopped-flow injection spectrophotometry; ETAAS: electrothermal atomic absorption spectrometry.

River water: Xiangjiang River, Xiangtan, China; Sewage water: Xiangtan University, Xiangtan, China; Pond water: Xian-feng village, Xiangtan, China.