Microwave radiation in analytical chemistry: the scope and prospects for application

Кубракова, И. В.

doi:10.1070/rc2002v071n04abeh000699

Cited by 48 publications

(11 citation statements)

References 61 publications

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“…The influence of MWT is demonstrated in DSC thermograms of PVCL40‐P and PVCL40‐P(MWT) [Figure 6], where endotherms at T = 79.5°C and 79.2°C, respectively. The heat of reaction proportional to the area under the peak is somewhat larger for PVCL40‐P than for PVCL40‐P(MWT), which agrees with the main drying effect of MWT 2 and results of the X‐ray diffraction analysis.…”

Section: Resultssupporting

confidence: 82%

“…Microwave impact is one promising method of lowering power inputs and increasing the formation rate of final products 1–4 . The attraction of an unionized electromagnetic impact is conditioned by the possibility of its application for homogeneous and heterogeneous systems, low inertance, inhomogeneity of material heating over the entire bulk, and selective heating of components of a mixture of substances.…”

Section: Introductionmentioning

confidence: 99%

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The impact of intense types of effects on poly(N‐vinyl caprolactam) and composites in the system nanoscale anatase – poly(N‐vinyl caprolactam)

Chikhacheva

Safyanova

Тимаева

et al. 2020

J of Applied Polymer Sci

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For the first time, the effects of microwave and ultrasonic treatments and an alternating electric field on poly(N‐vinyl caprolactam) (PVCL40) both in the original and in the composite with nanoscale anatase have been studied. Comparison of the results of studying the samples by X‐ray diffraction, IR spectroscopy, differential scanning calorimetry (DSC) before and after treatments allowed us to identify, and explain the response of objects to different types of effects with a change in their characteristics. Analysis and comparison of the results do not exclude the misorientation of the PVCL40 domains in thin films (microwave processing), which becomes flat‐ordered after their rubbing, the destruction of the PVCL40 and the disorder of the side substituent are found, accompanied by a change in the periodicity chains (microwave processing, electric field), a decrease in the water content in the system (microwave processing) and amorphization of nanoscale anatase (microwave processing, electric field) were revealed. The implementation of the revealed effects as response to microwave, ultrasonic, and electric field treatments on a similar type of polymers with a different composition and structure is not ruled out.

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Section: Resultssupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

The impact of intense types of effects on poly(N‐vinyl caprolactam) and composites in the system nanoscale anatase – poly(N‐vinyl caprolactam)

Chikhacheva

Safyanova

Тимаева

et al. 2020

J of Applied Polymer Sci

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“…Severe conditions (conc. HNO 3 , sometimes in mixture with other mineral acids, and temperature above 220 ° C) and the simultaneous action of several factors (electromagnetic radiations, temperature, and pressure) on the reaction mixture are necessary for the efficient decomposition of the organic matrix of natural carboncontaining samples [18]. These conditions ensure the decomposition of various samples within 10-30 min.…”

Section: Resultsmentioning

confidence: 99%

Determination of Trace Noble Metals in Natural Samples Using Hyphenated Methods

et al. 2005

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New ecological and geochemical problems call for the sophistication of techniques for analyzing platinum samples [1]. Special attention is given to the search for and study of new potential sources of nontraditional platinum raw materials among organic substances at different stages of metamorphism (coals, carbonaceous shales, iron-manganese concretions, etc.) [2,3]. The study of the anomalous iridium distribution in some sedimentary rocks and the control of environmental contamination with platinum, iridium, and rhodium because of the use of combustion catalysts are also urgent tasks [4]. These problems are complicated by the test samples including high concentrations of organic substances and low concentrations of noble metals, which occur as various species insufficiently studied yet [5,6].The most common natural species of noble metals are native metals (including invisible colloidal metals), as well as intermetallides, sulfides, tellurides, selenides, arsenides, and antimonides [4,7]. Being siderophils, noble metals form compounds with iron and iron-group elements, particularly chromites. In carbon-containing natural samples, organic compounds of noble metals can also be found, along with the most common native species and solid solutions (e.g., platinum-copperiron) [2,6]. The ecological contamination with platinum and palladium is usually due to the presence of metal nanoparticles in dust and soil [8]. In at least the two latter cases, acid decomposition can be the most efficient method for solubilizing noble metals (provided the complete oxidation of the organic matter).Inductively coupled plasma-mass spectrometry (ICP-MS) (including its isotopic dilution version), electrothermal atomization-atomic absorption spectrometry (ETA-AAS), and inductively coupled plasma-atomic emission spectrometry (ICP-AES) offer most promise for the instrumental determination of trace noble metals [4,5,[8][9][10]. The potentials of each method used in the combined analytical schemes depend on the analyte nature and concentration, as well as on the presence of interfering matrix components, which affect the choice of the determination parameters.The possibilities of different instrumental methods in determining noble metals, as found from the generalized data of some analytical laboratories, are presented in Table 1 [11]. It can be seen that the actual detection limits for noble metals are relatively similar. At the same time, each method has its own unique features; these will be considered below.In spite of the high tolerance for the matrix compositions of test solutions and high efficiency of multielement determination, the ICP-AES is insufficiently sensitive for the direct determination of noble metals in solutions after the decomposition of most of the natural samples. Hyphenated techniques involving the separation of matrix components allow ICP-AES to be used for determining trace noble metals, although some problems arose. For example, the determination of gold is characterized by a significant and rapidly appearing memor...

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“…Despite tremendous efforts in automation and in the development of new chemical methods in the past decade, there is still an overall deficiency in new chemical technology [148]. Flow microwave-assisted processes can be regarded as a significant breakthrough towards more efficient syntheses, including multistep, parallel, and/or combinatorial sequences [149][150][151].…”

Section: Conclusion and The Futurementioning

confidence: 99%