The document discusses various analytical techniques in toxicology for the analysis and identification of drug metabolites and toxic substances. Key methods include protein precipitation, liquid-liquid extraction, solid-phase extraction, and several chromatography techniques such as LC-MS/MS and GC-MS, each with their advantages and applications in biomedical analyses. It also covers qualitative and quantitative tests for specific toxins like arsenic, mercury, cyanide, and pesticides, highlighting the clinical implications of toxic exposure.