Stability studies of arsenic,selenium,antimony andtellurium species in water,urine,fish an dsoil extracts using HPLC/ICP-MS

摘要

The stability of arsenic, selenium; antimony and tellurium species in water and urine (NIST SRM 2670n) as well as in extracts offish and soil certified reference materials (DORM-2 and NIST SRM 2710) has been in- vestigated. Stability studies were carried out with As(III), As(V), arsenobetaine, monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), phenylarsonic acid (PAA), Se(IV), Se(VI), selenomethionine, Sb(III), Sb(V) and Te(VI). Speciation analysis was perfom1ed by on-line coup- ling of anion exchange high-performance liquid chro- matography (HPLC) with inductively coupled plasma mass spectrometry (ICP-MS). Best storage of aqueous mixtures of the examined species was achieved at 3 °C whereas at -20 °C species transfom1ation especially of se- lenomethionine and Sb(V) took place and a new selenium species appeared within a period of 30 days. Losses and species transformations during extraction processes were investigated. Extraction of the spiked fish material with methanol/water led to partial conversion of Sb(III), Sb(V) and selenomethionine to two new antimony and one new selenium species. The other arsenic, selenium and tellurium species were almost quantitatively extracted. For soil spiked with MMA, PAA, Se(IV) and Sb(III), recoveries after extraction with water and sulfuric acid (0.01 mol/L) were below 20%.