Investigation of chemical modifiers for the determination of boron by electrothermal atomic absorption spectrometry

A fast and efficient method for the determination of boron in aqueous solutions is described, using electrothermal atomic absorption spectrometry with a transversely heated graphite tube atomizer. The investigations were carried out with calcium chloride, zirconium chloride, and with mixtures of both reagents as chemical modifiers. Furthermore, the influence of zirconium treated graphite tubes on the sensitivity and stability of the analytical results was investigated. The developed method is suitable for the determination of boron over a concentration range from 0.1 to 2.0 mg/l without any additional dilution or enrichment steps. The atomization temperature could be lowered to 2550°C, and the best characteristic mass for boron of 0.19 ng was obtained for a zirconium-treated graphite tube and the addition of calcium chloride as a chemical modifier to the measurement solution. Sensitivity and precision of the measurement did not change significantly over an 8-h working day under these conditions.