1 Method Summary
Diethylenetriaminepentaacetic acid‑calcium chloride‑triethanolamine (DTPA‑CaCl₂‑TEA) buffer solution at pH 7.3 is used as extracting agent to chelate and extract available copper from soil.
DTPA acts as chelating agent; calcium chloride inhibits dissolution of free calcium carbonate in calcareous soil to avoid interference caused by release of wrapped zinc, iron and other elements; triethanolamine serves as buffer to maintain solution pH at approximately 7.3 and also suppresses calcium carbonate dissolution.
The copper concentration in extracting solution is determined by atomic absorption spectrophotometer with air‑acetylene flame.
2 Scope of Application
Applicable to the determination of available copper content in soil with pH＞6.
3 Reference Standard
NY/T 890-2004 Determination of Available Zinc, Manganese, Iron and Copper Contents in Soil by DTPA Extraction, Clause 7.3.1 Flame Atomic Absorption Spectrometry
4 Testing Instruments
· Flame Atomic Absorption Spectrophotometer 1 set — Copper hollow cathode lamp
