Determination of cadmium in water samples by fast pyrolysis – Chemical vapor generation atomic fluorescence spectrometry using titanium hydride powder as a hydrogen source

Highlights: • Cd can form volatile species with TiH₂ by fast pyrolysis reaction. • Cd signal intensity can remain unchanged over a wide acidity range. • This method has a good tolerance to interferences from transition metal ions. • LOD and efficiency of Cd were 0.21 ng and 60%, respectively. -- Abstract: A method for the determination of cadmium by pyrolysis chemical vapor generation (Py-CVG) atomic fluorescence spectrometry using titanium hydride (TiH₂) as a reducing agent has been proposed. Under optimal conditions (T = 500 °C, TiH₂ = 20 mg, argon = 350 ml min⁻¹), the mass and concentration detection limits were 0.21 ng and 0.52 ng ml⁻¹, respectively, and precision(RSD,%)for ten replicated measurements for a 5 ng cadmium was 5.2. The proposed method has not only a good interference tolerance but also a very stable signal plateau in a very wide range of acid concentrations. The method was successfully applied to analyze trace amounts of cadmium in two reference materials for environmental water, and the results were in good agreement with the certified reference values.