ANALYTICAL INVESTIGATIONS OF ANTIMONY-EDTA COMPLEXES AND THEIR USE IN SPECIATION ANALYSIS

作者：Kolbe Falko; Mattusch Juergen; Wennrich Rainer; Weiss Holger; Sorkau Eduard; Lorenz Wilhelm^*; Daus Birgit

来源：Fresenius Environmental Bulletin, 2012, 21(11C): 3453-3458.

• antimony speciation
• EDTA complexes
• sample pre-treatment
• ESI-MS

An antimony speciation method was optimized using HPLC-ICP-MS and EDTA as eluent with the aim to minimize the carbon intake into the ICP-MS system and to lower the limits of detection. The flow rate was significantly decreased to 0.4 mL min(-1) by using a HPLC column with a smaller inner diameter (Hamilton PRP X-100, 150 mm x 2.1 mm, 10 mu m). This results in short retention times, low limits of detection (<50 ng L-1) and a considerable reduction of carbon intake.
However, different sensitivities were observed for Sb(V) and Sb(III). For understanding this phenomenon, structural information of the formed complexes were achieved via ESI-MS measurements. Antimonite was proven to be mainly complexed as negatively charged [Sb(EDTA)](-) independently from initial reference substance: Sb2O3, SbCl3 and Sb(III)-tartrate. For a complete formation of the Sb(III)-EDTA complex a pre-treatment of the samples and standard solutions was found to be necessary. The addition of EDTA (final concentration 20 mM) results in similar intensities for Sb(V) and Sb(III). The EDTA complex was proven to be formed completely in less than two minutes and in water samples with initial pH values of 2-11.

• 出版日期2012