T. Yu. Alekseeva

Determination of platinum and palladium in dead catalysts using inductively coupled plasma atomic emission spectrometry after sample digestion by high-temperature fusion

A technique for the determination of platinum and palladium in dead catalysts using ICP-AES after sample digestion by high-temperature fusion with potassium pyrosulfate is described. The technique is universal; it offers the possibility to analyze various brands of catalysts and their mixtures at a content of platinum and palladium of 0.1% to whole units of percent in a short time. The accuracy of results of determination of platinum and palladium is confirmed by comparison with the data of interlaboratory control. The relative standard deviation in the developed technique is 4–2.5% for the content of platinum and palladium of 0.1 to 0.5% and 2–1% for higher concentrations of these elements.

Chemical preparation of samples of dead automobile catalyzers for subsequent determination of platinum, palladium, and rhodium using atomic emission spectrometry with inductively coupled plasma

Systematic studies of different methods for decomposition of samples of dead automobile catalyzers (ACs) on a ceramic base using mixtures of mineral acids and high-temperature alloying with the aim of subsequent determination of platinum, palladium, and rhodium using atomic emission spectrometry with inductively coupled plasma are presented. The behavior of matrix components of dead ACs under the conditions of sample decomposition is investigated. The effect of the results of determining platinum group metals is studied. The relative standard deviation of the results of the analysis performed according to the developed techniques is 11-9% at platinum, palladium, and rhodium concentrations ranging from 0.01 to 0.3%.

Direct atomic-absorption determination of platinum, palladium, and rhodium in dead ceramic-based autocatalysts

The data on the effect of different concentrations of components of dead automobile catalysts on determination of platinum, palladium, and rhodium using the method of ETAAS are obtained and systematized. The conditions for direct atomic-absorption determination of Pt, Pd, and Rh are optimized. The technique of atomic-absorption determination of PM in secondary raw and technogenic materials is developed (n × 10−4−n × 10−1 wt %, sr = 0.12–0.07).

Sorption-atomic-absorption determination of platinum, palladium, and rhodium in dead autocatalysts

The conditions for determination and group concentration of platinum metals (PMs) in the presence of matrix components using new S,N-containing complex-forming sorbents in solutions obtained after decomposition of decontaminated autocatalysts are proposed. The technique of atomic-absorption determination of PMs from a solution (n × 10−4−n × 10−2; sr = 0.15–0.07) and a solid phase (n × 10−5−n × 10−4; sr= 0.20–0.12) is developed.

Decomposition of samples of used ceramic-based automotive catalytic converters in analytical autoclaves with resistive heating

Different ways of chemical sample preparation of used automotive catalytic converters (ACCs) in analytical autoclaves with resistive heating are studied for subsequent determination of platinum, palladium, and rhodium by AES-ICP. Conditions of autoclave decomposition of ACCs samples using binary mixtures of HCl-HNO3 and HCl-H2O2 that allow achieving quantitative extraction of platinum group metals into a solution without complete decomposition of the sample are determined. Universal methods of analysis of used ceramic-based automotive catalytic converters are developed. The relative standard deviation of the analysis results according to the developed techniques is 11-5% rel. at contents of platinum, palladium, and rhodium from 0.03% to 0.3%.

Elaboration of the technique of atomic emission detection with inductively coupled plasma of platinum metals in chamotte waste with autoclave sample preparation and design of the experiments

A comprehensive method for atomic emission analysis was developed with the use of mathematical planning of experiment developed with autoclave sample preparation to control the content of platinum metals in chamotte waste of glass manufacture.

Determination of high concentrations of palladium by combined use of gravimetric and spectral analysis

A method of determination of palladium is developed which combines precipitation of palladium with dimethylglyoxime, recovery of weighed form of metallic palladium, and subsequent determination of coprecipitated impurities in an isolated precipitate by atomic emission spectrometry with inductively coupled plasma and arc sources of excitation with the aim of introducing a correction into the results of gravimetric analysis. The evaluation of the error of palladium determination by the proposed scheme characterized as the total error of two independent stages of analysis (gravimetry and atomic emission spectrometry), which have different metrological characteristics, is performed. The total error of analysis in determination of the threshold concentrations of impurities in the separated palladium precipitate does not exceed the error characteristic of gravimetric analysis (RSD ≈ 0.2–0.5%). The given scheme makes it possible to substantially reduce the labor intensity and time of analysis compared to the classical scheme of gravimetric analysis.

Determination of macroconcentrations of platinum by combined application of gravimetry and inductively coupled plasma—Atomic emission spectrometry

A combined method for macroconcentrations of platinum determination in chloroplatinic acid and industrial concentrate obtained during processing of some types of electronic engineering scrap that is based on a combination of gravimetric precipitation of platinum by ammonium chloride with subsequent determination of a residual concentration of platinum in a filtrate using the ISP-AES method is developed. The errors at each stage of analysis, as well as the total error, are estimated. It is shown that the accuracy of macro-concentrations of platinum determination using the combined method is not inferior to the accuracy of classical gravimetric analysis (the relative standard deviation does not exceed 0.15% for 15–40% wt concentrations of platinum). The combined method of analysis based on a combination of gravimetry and ISP-AES makes it possible to decrease labor expenditures and the time of analysis as compared to the classical one.

Comparative evaluation of the high-temperature fusion and the autoclave dissolution of process concentrates upon gravimetric determination of palladium

Various techniques for decomposition of process concentrates with a high content of palladium, such as fusion with potassium pyrosulfate and dissolution in autoclaves, with the purpose of the following gravimetric determination of palladium are described. It is shown that the optimal method for transferring the sample into the solution is its dissolution in a mixture of HCl and HNO3 (3: 1) using analytical autoclaves. The conditions of the autoclave dissolution (the composition of the acid mixture, the temperature, and the dissolution time) are determined. The relative standard deviation of the analysis results is 0.3% for a content of palladium of 60–80%.