Effect of organic solvents on the flame atomic absorption spectrometry of copper using discrete nebulisation of mixed aqueous solutions

Abstract

The relationships between the relative viscosity of mixed aqueous-organic solvents and signal height, signal area, aspiration time and the ratio of the signal area to the aspiration time have been investigated in the flame atomic absorption spectrometry of copper with discrete nebulisation of 100 µl of solution under constant flame conditions. The signal area and aspiration time increased with increasing viscosity, while the signal height varied irregularly with the viscosity and with the combination of solvents. The aqueous-organic solvents studied were the ethanol-water, acetone-water, propan-1-ol-water and butan-1-ol-water systems. For 43%m/m(50%V/V) aqueous ethanol and acetone solutions, i.e., at their maximum viscosities, the signal areas were ca. 2.3 and 1.9 times larger than that for the aqueous solutions alone, but the signal heights were 0.80 and 1.06 times larger, respectively. In the presence of 25%m/m ethanol, copper was determined in bovine liver by the signal area and absolute mass methods using 50-µl injection volumes, with good sensitivity and accuracy.