Unmodified manganese ferrite nanoparticles as a new sorbent for solid-phase extraction of trace metal–APDC complexes followed by inductively coupled plasma mass spectrometry analysis

Abstract

The applicability of MnFe 2 O 4 nanoparticles as a new sorbent for group pre-concentration of V, Co, Ni, Cu, Zn, As, Se, Cd and Pb was investigated and compared with that of magnetite nanoparticles. A solid-phase extraction (SPE) of target analytes based on sorption of their hydrophobic complexes with ammonium pyrrolidine dithiocarbamate (APDC) on the surface of unmodified nanoparticles (NPs) was optimized. Magnetic NPs with retained metal complexes were easily separated from the bulk solution by a permanent magnet applied for 5 min. Analyte restoration in the final solution was accomplished by heating with 0.5 mL of 7 mol L À1 nitric acid. The obtained solutions were suitable for continuous nebulization in ICP-MS. Spectral and non-spectral matrix effects for urine analysis (direct and after SPE) were studied and adequate calibration strategies are suggested. Under optimized conditions the magnetically assisted SPE procedure enables enrichment of target analytes by factors of between 7.4 and 10, with linear dynamic ranges of 1-100 mg L À1 for V, Co, Ni, Cd, Pb and 10-1000 mg L À1 for Zn, As, Se and method detection limits in the interval 0.01-0.7 mg L À1 . The relative standard deviations (RSD%, for 10 mg L À1 V, Co, Ni, Cd, Pb and for 100 mg L À1 Zn, As, Se, n ¼ 6) were less than 5.5%. The accuracy of the method was evaluated by analysing urine certified reference material SeronormÔ Trace Elements Urine 201205 and obtained recoveries were in the range 85-109%. For correct determination of As and Se in urine, a preliminary microwave sample treatment with a mixture HNO 3 + H 2 O 2 was needed, but it led to a worsening of method detection limits. The developed method was successfully applied for analysis of human urine.

Current developments in clinical sample preconcentration prior to elemental analysis by atomic spectrometry: a comprehensive literature review

“…The most common matrices are hair and urine, but there are also some examples of tissues and biological uids such as bovine liver 22 and plasma. 21 Metal oxide nanoparticles 13,21,[23][24][25][26][27][28][29][30][31][32][33][34] and carbon-containing nanomaterials 6,7,11,13,17,20 have been found to be useful in SPE for metal extraction in clinical samples.…”

“…According to the reported publications, by varying the amount of MNPs used it offers high exibility to accommodate different sample volumes and types of analytes (between 3 mL (ref. 26) and 350 mL (ref. 25)), which is important for clinical analysis where a limited amount of sample is available and the analyte concentration is oen very low.…”

Insitu ultrasound-assisted synthesis of Fe3O4 nanoparticles with simultaneous ion co-precipitation for multielemental analysis of natural waters by total reflection X-ray fluorescence spectrometry

“…Despite the fact that most of the available techniques for trace metal analysis provide a high sensitivity, and direct analysis without sample pre-treatment is feasible for many environmental samples, a preconcentration-separation procedure may be required for determination of trace levels and/or removal of matrix effects. At present, there are a variety of preconcentration methods for trace elements, including solid phase extraction (SPE), [13][14][15][16][17] solid phase microextraction (SPME), 18,19 co-precipitation, 20 cloud-point extraction (CPE) 21 and miniaturized liquidliquid microextraction techniques. 22 SPE is one of the most effective methods for preconcentration of trace metals because of its simplicity, rapidity and ability to attain high enrichment factors.…”

A glance at achievements in analytical atomic spectrometry in Central and Eastern Europe

“…The present online themed issue is a collection of seven papers of researchers from Bulgaria (Tsalev and Ivanova, 1 Stefanova et al 2 ), Czech Republic (Hraníček et al, 3 Moraes et al, 4 Musil et al 5 ), Poland (Jamróz et al 6 ), Romania (Frentiu et al 7 , Constantinescu et al 8 ) and Slovak Republic and Hungary (Andruch et al 9 ). The collection includes two reviews, one overview and six original research papers.…”

“…As a result, under optimal conditions related to the generation of Ag species, their transport to the atomizer as well as trapping, volatilization and atomization temperatures, a very good analytical performance is achieved. Stefanova et al 2 propose the use of magnetic nanoparticles of MnFe 2 O 4 as a new sorbent for the group retention of hydrophobic complexes of ammonium pyrrolidine dithiocarbamate with V, Co, Ni, Cu, Zn, As, Se, Cd and Pb and preconcentration of these elements prior to their determination by inductively coupled plasma mass spectrometry (ICP-MS). This solid phase extraction procedure described gives detection limits in the interval of 0.01-0.7 mg L À1 while its suitability is illustrated by the analysis of human urine.…”