Stable isotopic composition of perchlorate and nitrate accumulated in plants: Hydroponic experiments and field data.

Natural perchlorate (ClO) in soil and groundwater exhibits a wide range in stable isotopic compositions (δCl, δO, and ΔO), indicating that ClO may be formed through more than one pathway and/or undergoes post-depositional isotopic alteration. Plants are known to accumulate ClO, but little is known about their ability to alter its isotopic composition. We examined the potential for plants to alter the isotopic composition of ClO in hydroponic and field experiments conducted with snap beans (Phaseolus vulgaris L.