4.1 The determination of metals in water often requires the measurement of total (suspended and dissolved) metals as well as soluble (dissolved) metals. In such cases, consistent and dependable digestion procedures must be used so that data derived for the total metals content is reliable.
4.2 The practices given are applicable to a wide variety of sample types for the purpose of preparing a sample for metals analyses by atomic absorption spectrophotometry or plasma emission spectroscopy (see Test Method D1976, Practice D3919, Practice D4691, and Test Method D4190) or plasma-mass spectrometry (see Test Method D5673) and have been shown to give good recovery in the following matrices: industrial effluents; waste water treatment plant influents, sludges, dewatered sludges, and effluents; river and lake waters; and plant and animal tissues. Elements which have shown good recovery include: copper, nickel, lead, zinc, cadmium, iron, manganese, magnesium, and calcium.
4.2.1 Good recovery for the indicated sample types and metals may not be achieved at all times due to each sample's unique characteristics. Users must always validate the practice for their particular samples.
4.3 The analytical results achieved after applying these practices cannot necessarily be deemed as a measure of bioavailable or environmentally available elements.
4.4 These three practices may not give the same recovery when applied to the same sample, nor will they necessarily give the same results as achieved using other digestion techniques. An alternate digestion technique is Practice D4309.
1.1 Most atomic absorption and plasma emission spectroscopy, and plasma-mass spectrometric test methods require that the metals of interest be dissolved in a liquid phase before being introduced into the spectrophotometer. These practices describe digestion or dissolution procedures whereby analyte metals associated with the solid fraction of a sample can be brought into solution for subsequent analysis. The following practices are included:
| Sections |
Practice A—Digestion with Mineral Acids and | 8199;8 through 13 |
Practice B—Digestion with Mineral Acids and |
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