Apha emission

Cadmium in acidified aqueous solution may be analyzed at trace levels by various instrumental techniques such as flame and furnace atomic absorption, and ICP emission spectrophotometry. Cadmium in solid matrices is extracted into aqueous phase by digestion with nitric acid prior to analysis. A much lower detection level may be obtained by ICP-mass spectrometry. Other instrumental techniques to analyze this metal include neutron activation analysis and anodic stripping voltammetry. Cadmium also may be measured in aqueous matrices by colorimetry. Cadmium ions react with dithizone to form a pink-red color that can be extracted with chloroform. The absorbance of the solution is measured by a spectrophotometer and the concentration is determined from a standard calibration curve (APHA, AWWA and WEF. 1999. Standard Methods for the Examination of Water and Wastewater, 20th ed. Washington, DC American Public Health Association). The metal in the solid phase may be determined nondestructively by x-ray fluorescence or diffraction techniques. 

APHA. 1989d. Metals-Plasma emission spectrometry, 3120B. Inductively coupled plasma (ICP) method. In Standard methods for the examination of water and wastewater. 17th Edition. Washington, DC American Public Health Association, 3-54-3-63. 

AAS = atomic absorption spectrometry APDC = ammonium pyrrolidine dithiocarbamate APHA = American Public Health Association EPA = Environmental Protection Agency FPD = flame photometric detection ICP/AES = inductivity coupled plasma atomic emission spectroscopy MED = microwave emission detector MIBK = methyl isobutyl ketone NIOSH = National Institute for Occupational Safety and Health XRF = x-ray fluorescence... 

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