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The article reviews an application of double deposition/accumulation and stripping steps as a new and beneficial manner of decreasing a detection limit and/or interferences elimination in stripping voltammetric determination of inorganic ions: Pb(II), Cd(II), Tl(I), U(VI), Au(III), As(III), Se(IV), In(III), Co(II), Cu(II), Bi(III) and Ga(III). A simple design of four‐electrodes system, containing two working electrodes differing in their surface area, allows for conducting two preconcentration and two stripping steps in one measurement cycle and in one voltammetric cell. Considerable analytes preconcentration and, consequently, an increase of sensitivity of determinations was obtained by conducting the first stripping step in a small volume of a solution near the microelectrode surface. An appropriate selection of the conditions of the first deposition/accumulation and the first stripping steps allowed for a minimization/elimination of interference effects. The proposed procedures allows for ultra‐trace levels determinations of mentioned inorganic ions (often impossible to determine by means of traditional three‐electrodes systems) without additional preconcentration outside the electrochemical cell and with the use of mercury‐free electrodes. [ABSTRACT FROM AUTHOR]

In the control of environmental pollution, it is essential to make adequate sampling, the following sample treatment, to continue the analysis of possible contaminants. To achieve a satisfactory analysis is essential to use the most suitable analytical technique, for each type of sample, type of analysis, etc. This contribution has made a thorough review of the most important analytical techniques for the control of environmental pollution depending on the type of sample, whether it is organic or inorganic and in which physical state the sample is.

Gold-cellobiose nanocomposites (GCNCs) were synthesized by reducing gold salt with a polysaccharide, cellobiose. Here, cellobiose acted as a controller of nucleation or stabilizer in the formation of gold nanoparticles. The obtained GCNCs were characterized with UV-visible spectroscopy; Zetasizer and Fourier transform infrared (FT-IR) spectrophotometer. Moreover, 6-Mercapto-1-hexanol (MCH) was modified on GCNCs, and the MCH-GCNCs were used to determine the cellobiase activity in compost extracts based on the surface plasmon resonance (SPR) property of MCH-GCNCs. The degradation of cellobiose on MCH-GCNCs by cellobiase could induce the aggregation, and the SPR absorption wavelength of MCH-GCNCs correspondingly red shifted. Thus, the absorbance ratio of treated MCH-GCNCs (A650/A520) could be used to estimate the cellobiase activity, and the probe exhibited highly sensitive and selective detection of the cellobiase activity with a wide linear from 3.0 to 100.0 U L-1 within 20 min. Meanwhile, a good linear relationship with correlation coefficient of R2 = 0.9976 was obtained. This approach successfully showed the suitability of gold nanocomposites as a colorimetric sensor for the sensitive and specific enzyme activity detection. [ABSTRACT FROM AUTHOR]

Abstract: Advances and changes in practical aspects of ion-mobility spectrometry (IMS) have led to its widespread use for applications of environmental concern due to its unique characteristics, which include portability, ruggedness, relatively low acquisition costs and speed of analysis. However, limitations regarding the complexity of environmental samples and strict requirements on limits of detection have to be overcome. This article critically reviews existing environmental applications using IMS for the determination of different families of compounds. We also consider the analytical tools developed to solve the limitations regarding selectivity and sensitivity, including those approaches that have led to advances in the instrumentation of IMS and its combination with other techniques for extraction and pre-concentration of analytes, pre-separation of analytes and its coupling to other detection systems. Finally, we discuss current trends that facilitate the deployment of IMS for on-site or in-field analysis. [Copyright &y& Elsevier]

Abstract: Adding of relatively small amounts of N and C, on the order of 1×1014 cm−3 in the growing crystals of Czochralski Si (CZ-Si) is considered now as a tool for the control of the internal gettering processes based on the precipitation of oxygen. The sensitivity of the conventional procedure of measurements by Fourier transform infrared (FT-IR) spectroscopy measurements is not sufficient to determine, in a reliable manner, such concentrations of N and C. This report contains results of the implementation of the modified method of FT-IR measurements, which allows one to improve the sensitivity for more than one order of magnitude. The new method is based mainly on (1) the modified FT-IR system with enhanced photometric accuracy achieved by a suppression of the influence of the instabilities, and (2) using Brewster geometry to suppress the interference effects. The method contains built-in checking of the achieved accuracy of the recorded spectrum. The examples of the determination of [N] and [C] on the 1014 cm−3-level in 2mm thick samples as well as in industrial wafers are presented. [Copyright &y& Elsevier]