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Direct and simultaneous determination of metal impurities in catalysts based on platinum group elements

100%

Abusenaina A., Vojteková V., Flórián K., Poperníková Z., Mičková V., Hámborská M., Ružičková S.

issue 6

678-686

Production of new catalysts requires effective analytical quality control. The study of trace element composition of heterogeneous catalysts, based on C+PdO, using atomic emission spectrometry (AES) was carried out. A new method for the direct solid-state analysis by means of AES with direct current arc discharge was developed. On the basis of the qualitative analysis of elements, Al, Fe, Ni, Si and Ti have been identified, and for these elements, the quantitative method of determination has been developed. Optimization of excitation parameters and validation of the analytical method are presented. Calibration samples of the following composition were prepared: graphite powder (as a matrix), 3% of PdO and increasing contents of determined element oxides (spectrally pure). Calibrations were calculated by means of the least squares method. Working range for element impurities was from 1% to 0.0003%, and the limits of quantification - LOQ, (10-σ criterion) varied in the range from 0.002% (Ti) to 0.0038% (Si). For the control of active component, palladium was calibrated (working range - 0.01%–10.00%; LOQ −0.027%). The developed method can be used, also, for the elemental determinations of the other carbon based catalysts with the different active components (of platinum group elements).

Sono-extraction as a pretreatment approach for the screening evaluation of element mobility of sediment samples

84%

Blašková J., Vojteková V., Nováková J., Mackových D., Bazeľ Y., Lapčík L., Poperníková Z., Abusenaina A.

Open Chemistry

2013

vol. 11

issue 7

1201-1212

Application of economically important and time saving pretreatment for the screening element mobility evaluation of contaminated sediments is presented. Ultrasonically-assisted single-step extraction (USAE) was carried out by EDTA solution. The extraction time of USAE was optimized and obtained results were compared with results estimated by conventional (EDTA extraction) and by sequential extraction (modified BCR protocol). The original three step BCR protocol was modified by addition of the first step (water leaching) and the fifth step, total digestion of sediment residue (acid mixture with HF). Zn, Cu and Pb have been determined in extracts by ICP-OES. Good conformity of the ultrasonically-extracted element contents and sum of contents, extracted during first three steps (water-soluble, acid-extractable, reducible - i.e., the most mobile fractions) of sequential extraction, was found. The sono-extraction reduced operating time of the first three steps of sequential extraction from 48 h to 15 min. Thus, USAE can serve as a rapid screening assessment of the mobile and potentially mobile element portions in sediments and other similar solid state environmental media. Analytical quality control was realized by comparison of the sums of element contents obtained at individual (five) extraction steps. Total element contents were also determined by an independent method (XRF).

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2 Open Chemistry

1 2014

1 2013

2 Abusenaina A.

2 Poperníková Z.

2 Vojteková V.

1 Bazeľ Y.

1 Blašková J.

1 Flórián K.

1 Hámborská M.

1 Lapčík L.

1 Mackových D.

1 Mičková V.

1 Nováková J.

1 Ružičková S.

Search results

Direct and simultaneous determination of metal impurities in catalysts based on platinum group elements

Sono-extraction as a pretreatment approach for the screening evaluation of element mobility of sediment samples