تسجيل الدخول

تسجيل

Metals and anions

المؤلف:  Sue Jickells , Adam Negrusz (Editors)

المصدر:  Clarkes Analytical Forensic Toxicology

الجزء والصفحة:  P101-102

2026-09-21

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Metals and anions

Metals and anions form an important, but disparate, group of poisons that present many difficulties in their systematic chemical analysis. Acute poisoning with these agents is rare in developed countries, but remains common in many underdeveloped parts of the world. Chronic poisoning, as a result of industrial or environmental exposure, occurs in many countries. The toxicity of metallic poisons may be influenced by the chemical nature of the compound ingested (valence state, solubility, inorganic or organic compound) and the route of admin istration. Inhalation of vapours (e.g. arsine, hydrogen cyanide and mercury phosphine) can cause acute toxicity, including rapid death. The signs and symptoms of acute poisoning may differ from those associated with chronic tox icity. Some metallic (e.g. arsenic) and anionic (e.g. cyanide) substances undergo extensive metabolism after ingestion. These factors have a significant bearing on analytical investigations applied to biological materials and their interpretation. It is important in individual cases, therefore, to know whether poisoning resulted from acute, chronic or acute-on-chronic expo sure. Of equal importance is the time of specimen collection in relation to the alleged time of ingestion or exposure. The wide range of metallic or anionic poisons that might be involved in any case of suspected poisoning means that great care is required in the collection of appropriate specimens and the selection of toxicological and other tests. There is no simple systematic way to investigate cases for which the history is uncertain and the identity of the poison unknown. The investigation is often led by a process of elimination of the more likely causes of poisoning (e.g. pharmaceuticals and illicit drugs), and then a careful examination of the detailed history of the patient or deceased, in particular any access to compounds associated with industrial and agricultural use. Considerable advances in analytical techniques for measuring metals in biological fluids have been made since the early 1980s, particularly in electrothermal atomic absorption spectrometry (ETAAS), inductively coupled plasma–mass spectrometry (ICP-MS) and ICP coupled with atomic emission spectrometry (ICP-AES). Table 4.7 summarises methods for analysis of metallic elements.