Study on the chemical speciation of trace elements in stenoloma chusana (L.) Ching

The primary and second speciation of eight trace elements in Stenoloma chusana (L.) Ching were determined by atomic absorption spectrometry. The results of primary speciation showed that the content characters of eight elements in primary sample are as follows: Ca > Mg > Fe > Mn > Cu > Zn > Cr > Ni. The total extraction rations of Ni and Mg are more than 50% and those of the rest elements are less than 40%. The residue rations of Cr and Zn are higher (88.09% and 81.35%) than those of other elements. The residue ration of Ni is the least (63.09%). The results of second speciation showed that the contents of eight elements in particulate are far more than that in dissolved. Eight elements exist mostly in inorganic forms after extraction of CHCl₃. The contents of free ions form of Zn, Ca and Mg are more than 75%. Mn hasn't any free ions form. After the separation of D-411 Chelating resin, the content of Zn in labile form is 62.82%. The contents of else elements in stable form are higher than those in labile form and Ni hasn't any labile form.