In accordance with this discovery, it is an object of the invention to provide an economical system for {HEAD ~ the rapid extraction} of exchangeable ions from soils or sediments under {TAIL ~ ambient oxidation reduction potentials} 
under
In accordance with this discovery , it is an object of the invention to provide an economical system for { HEAD ~ the rapid extraction } of exchangeable ions from soils or sediments under { TAIL ~ ambient oxidation reduction potentials }
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