title: Determination of ultra trace amounts of copper by a multi-injection technique of electrothermal atomic absorption spectrometry after using solid-phase extraction.
abstract: A new method using a multi-injection technique combined with SPE was developed for the determination of copper (Cu) in environmental samples. The method is based on SPE of copper ions on naphthalene as its 2-(5-bromo-2-pyridylazo)- 5-diethylaminophenol (5-Br-PADAP)-ammonium tetraphenylborate complex, in the pH range 6.0-9.5, and determined by electrothermal atomic absorption spectrometry. No chemical modifier is required in the graphite furnace. The detection limit can be reduced to 1.5 ng/L using an injection volume of 25.0 μL (five 5.0 μL) without interference by the matrixes. The optimum pyrolysis and atomization temperatures were 500 and 2200°C, respectively, for the concentrated solution of Cu. The sensitivity for 1% absorption was 2.6 pg Cu. Eight replicate determinations for 0.1 μg Cu in 5.0mL dimethylformamide gave an RSD of 2.3% for a single injection and 2.7% for a multi-injection. The procedure was validated with certified reference materials and successfully applied to the determination of copper in water and plant samples.
authors: Fatemeh
authors: F
authors: Sabermahani
authors: Mohammad Ali
authors: MA
authors: Taher
mesh_terms: D001391:Azo Compounds / Q000737:chemistry; D003300:Copper / Q000032:analysis* / Q000302:isolation & purification; D057230:Limit of Detection; D009281:Naphthalenes / Q000737:chemistry; D010944:Plants / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000379:methods*; D013054:Spectrophotometry, Atomic / Q000379:methods*; D013775:Tetraphenylborate / Q000737:chemistry; D014867:Water / Q000032:analysis*
chemical_list: D001391:Azo Compounds; D009281:Naphthalenes; D014867:Water; C037882:2-(5-bromo-2-pyridylazo)-5-diethylaminophenol; D013775:Tetraphenylborate; D003300:Copper