Flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS) and spectrophotometric methods for determination of lead in environmental samples

Flow Injection Hydride Generation Atomic Absorption Spectrometry (FI-HG-AAS) and spectrophotometric methods have been used for determination of lead in environmental samples. The method, FI-HG-AAS is fast and can analyse one sample from solution within 30 seconds. The method is highly sensitive. The detection limit is 0.002 mg l(-1) for a 50 mu l injection leap. Along with FI-HG-AAS a spectrometric method has also been described. Utility of this method is, any laboratory that can afford a colorimeter can use this method for lead determination. The method is based on step wise removal of interfering cations by dithizone, dibenzyldithiocarbamate followed by final spectrophotometric determination using 4-(2-pyridylazo) resorcinol. The detection limit is 0.5 mg l(-1). These two methods have been tested for lead analysis in various Standard Reference Materials and applied for lead determination in Calcutta's environmental samples and lead in residential areas near a group of lead factories within Calcutta. Results of these two methods have been compared with ICP-AES and Flame-AAS.