Standardized and unified methods for determining phenols in natural and drinking waters and main trends of their development

This paper presents MAC (maximum admissable concentration) values of phenol and its derivatives in natural and drinking waters specified in the normative documents of Ukraine, Russia, the USA, Canada, Great Britain, and international organizations WHO and EU, and also provides data on standardized and unified methods for determining phenols at the MAC level. This paper has discussed directions of the development of techniques for determining phenols during the last fifteen years that are based on preliminary extractive or sorptive concentration and subsequent detection using photometric, gas chromatographic, fluorometric, and kinetic techniques of analysis, and also the high performance liquid chromatographic (HPLC) method with electrochemical and flame ionization detection.     

Finely dispersed composite iron-platinum and iron-gold powders

The physicochemical laws of the formation of Fe−Pt and Fe−Au oxalates have been determined. For the first time finely dispersed Fe−Pt and Fe−Au composite powders have been fabricated by thermal reduction. The physicochemical and biomedical properties of such powders are investigated. We show that the powders are corrosion-resistant, are almost monodisperse, have a hydrophilic surface, are nonpyrophoric, are harmless, are bactericidal, and withstand sterilization temperatures. Their magnetic properties can be controlled during formation. Colloid Chemistry and Water Chemistry Institute, Ukrainian Academy of Sciences, Kiev. Translated from Poroshkovaya Metallurgiya, Nos. 3-4(400), pp. 1–6, March–April, 1997.     

Inversion voltammetric determination of microconcentrations of Cd (II) and Zn (II) when they are jointly present in waters

The method of inversion voltamperometry was used to investigate electrochemical behavior of microconcentrations of Cd (II) and Zn (II) in waters on a mercury film electrode. We studied the impact of cadmium and zinc during their joint determination. We established optimal conditions for obtaining analytical signals of cadmium and zinc.     

Heat of Wetting the Surface of Very Fine Particles of Iron and Its Composites with Ag,Pt, Au,Cu, and Zn with Water

The heat of wetting for very fine iron powder and its composites with Ag, Pt, Au, Cu, and Zn prepared by a thermochemical method is measured. It is established that their surface is hydrophilic. This makes it possible to modify the surface of powders with different substances and create new materials intended for medicine and technics.

     

Finely dispersed composite iron—Silver powders

A thermochemical method has been used to make finely dispersed iron-silver composite powders for medical purposes. The physicochemical and biomedical properties have been examined. These Fe’MAg powders have been made with silver mass contents of 0.1, 1, 5, and 10%, and they have been found to be resistant to corrosion, nonpyrophoric, and bactericidal, and to have hydrophilic surfaces and to allow of thermal sterilization; during the formation of the powders, the behavior can be traced from the magnetic characteristics can be controlled depending on subsequent use. The powders can be used in medicine for example for the treatment of suppurating wounds, trophic ulcers, and so on.     

Micellar extraction concentration of microcomponents by phases of nonionic SAS at the cloud point

Main principles of the micellar extraction concentration of microcomponents from aqueous solutions by phases of nonionic SAS at the cloud point have been studied, and the data available in literature dealing with the use of micellar extraction for concentrating and separating ions of metals, organic compounds, and biologically active substances have been classified.     

Extraction-free determination of small amounts of perchlorate in waters

We have investigated determination of trace amounts of perchlorate and proposed the techniques for water analysis and its content. The determination was carried out in the form of an ionic associate with cetyltrimethyl ammonium after sorption of the white deposition on a stained paper filter and variations of diffusion reflection and also in the form of an ionic associate with rhodamine 6G after its sorption of the filter with the change the chemiluminescence intensity occurring after addition of the reagents CoCl₂, H₂O₂, and NaHCO₃. For preliminary concentrating and separation of perchlorate from interfering impurities standard modified sorbents were used. The detection limit of perchlorate constitutes respectively 20 and 0.4 μg/dm³.