قارن الطرق

	تحديد الأنواع الكيميائية للمعادن الثقيلة	الاختبارات السمية البيئية
المجال	الهندسة البيئية	الهندسة البيئية
العائلة	Process / pipeline	Process / pipeline
سنة النشأة	1979	1975
صاحب الطريقة	Tessier and hydrogeochemists	EPA and OECD
النوع	analytical and geochemical modeling pipeline	experimental measurement and analysis pipeline
المصدر التأسيسي	Tessier, A., Campbell, P. G. C., & Bisson, M. (1979). Sequential Extraction Procedure for the Speciation of Particulate Trace Metals. Analytical Chemistry, 51(7), 844–851.	OECD. (2011). Test Guidelines for Chemicals. OECD Publishing.
الأسماء البديلة	metal speciation, metal partitioning, bioavailability assessment, speciation analysis	toxicity testing, aquatic bioassay, ecotoxicity assessment, organism exposure testing
ذات صلة	3	3
الملخص	Heavy metal speciation is the analytical and geochemical determination of the chemical forms (species) and partitioning of toxic metals (lead, cadmium, chromium, zinc, copper) in soil, sediment, and water. Metal bioavailability—the fraction accessible to organisms—depends critically on speciation: metal bound to soil organic matter or iron oxides is immobile and non-bioavailable; dissolved or exchangeable metal is highly bioavailable and toxic. Speciation assessment informs remediation design, risk assessment, and contaminant fate prediction.	Ecotoxicological testing is a suite of standardized laboratory and field methods to assess the toxicity of chemical substances to aquatic and terrestrial organisms (fish, invertebrates, algae, plants, soil fauna). Developed by regulatory agencies (OECD, EPA, EMEA) since the 1970s, these tests measure lethal concentration (LC50, EC50) and sublethal endpoints (growth, reproduction, behavior) under controlled conditions. Ecotoxicological data support chemical hazard classification, environmental risk assessment, and regulatory approval of new substances.