Molecular non-thermal excitation spectrometry (MONES): a procedure for the determination of non-metals using diatomic molecules in the non-thermal (FANES) atomiser. Part 1. Determinations of fluoride and chloride ions by magnesium fluoride and magnesium chloride MONES. Plenary lecture

1987 ◽  
Vol 2 (6) ◽  
pp. 533 ◽  
Author(s):  
Klaus Dittrich ◽  
H. Fuchs
1984 ◽  
Vol 49 (10) ◽  
pp. 2349-2354 ◽  
Author(s):  
František Vláčil ◽  
Karel Koňák

The selectivity coefficients of the nitrate and chloride ions and of anionic chloro complexes of Au(III), Rh(III), Pd(II), and Pt(IV) for ion exchange on Spheron DEAE in the chloride form are determined by the dynamic method. the complex anion species formed are identified and the ion exchange nature of the sorption of precious metals on this sorbent is confirmed based on the elution order of the precious metals as determined previously by the column chromatography on Spheron DEAE using hydrochloric acid as the mobile phase. The effect of the presence of perchlorate in the mobile phase during the liquid chromatography of precious metals and during the chromatographic determination of nitrate traces is explained.


2018 ◽  
Vol 33 ◽  
pp. 02010 ◽  
Author(s):  
Anastasia Morzhukhina ◽  
Stanislav Nikitin ◽  
Elena Akimova

Aggressive environments have a significant impact on destruction of many reinforced concrete structures, such as high-rise constructions or chemical plants. For example, some high-rise constructions are equipped with a swimming pool, so they are exposed to chloride ions in the air. Penetration of aggressive chemical substances into the body of concrete contributes to acceleration of reinforced concrete structure corrosion that in turn leads to load bearing capacity loss and destruction of the building. The article considers and analyzes the main technologies for calculating penetration depth of various aggressive substances into the body of concrete. The calculation of corrosion depth was made for 50-year service life.


The Analyst ◽  
1992 ◽  
Vol 117 (6) ◽  
pp. 1019 ◽  
Author(s):  
Ma Asunci�n Herrero ◽  
Julia Atienza ◽  
Angel Maquieira ◽  
Rosa Puchades

CORROSION ◽  
10.5006/3562 ◽  
2020 ◽  
Vol 76 (8) ◽  
pp. 786-795
Author(s):  
Abraham A. Becerra Araneda ◽  
Mariano A. Kappes ◽  
Martín A. Rodríguez ◽  
Ricardo M. Carranza

Low potential pitting corrosion (LPPC) of Alloys 690 and 800 (UNS N06690 and N08800) was studied in neutral solutions, containing chloride ions from 0.1 M to 1 M and thiosulfate ions from 5 × 10−5 M to 10−3 M. LPPC occurred close to the corrosion potential (–0.25 VAg/AgCl) by a synergic effect of the chloride and thiosulfate ions. The threshold concentrations of aggressive species for LPPC occurrence were identified by potentiostatic tests with mechanical scratching of the surface, which yielded more conservative estimations compared to other electrochemical tests. The ranges of potential and concentration of chloride and thiosulfate where LPPC occurred and where it merged with the conventional chloride pitting were determined. The lowest threshold concentrations were measured in Alloy 800, with a lower Cr content than Alloy 690. Thermally-aged Alloys 800 and 690 had lower resistance to LPPC than the corresponding solution-annealed material. In 1 M chloride-based solutions, for aged Alloy 800, LPPC occurred at a thiosulfate concentration as low as 5 × 10−5 M; in 10−3 M thiosulfate-based solutions, the chloride threshold was 0.1 M. For thermally-aged alloys, pits propagated intergranulary in some experiments. In solutions with chloride and thiosulfate concentrations close to the threshold required for pitting, repassivation of LPPC was observed after a sustained period of pit growth, originally initiated by scratching the surface. Such a repassivation has not been reported before in the literature in chloride and thiosulfate solutions. Two possible explanations were presented for this phenomenon.


1967 ◽  
Vol 22 (4) ◽  
pp. 407-412 ◽  
Author(s):  
F. Pohlandt ◽  
G. Kohlhaw ◽  
H. Holzer

1. A reaction mixture, made from pig heart pyruvate oxidase, hydroxypyruvate, thiamine pyrophosphate, and magnesium chloride, is described in which thiamine pyrophosphate is almost quantitatively converted into 2-(1,2-dihydroxyethyl)-thiamine pyrophosphate (thiamine pyrophosphate-activated glycolaldehyde). This product can be isolated by ion exchange chromatography.2. 2-(1,2-dihydroxyethyl)-thiamine pyrophosphate can also be isolated from reaction mixtures of yeast transketolase with hydroxypyruvate, thiamine pyrophosphate, and magnesium chloride, but in very low yield.3. From non-enzymatic reaction mixtures containing thiamine pyrophosphate and a great excess of glycolaldehyde, a compound could be isolated, the tested properties of which were found to be the same as those of enzymatically prepared 2-(1,2-dihydroxyethyl)-thiamine pyrophosphate.4. 2-(1,2-dihydroxyethyl)-thiamine pyrophosphate gives rise to only 55% of the thiochrome which is produced from the same quantity of thiamine pyrophosphate. This behaviour can be used for the determination of relative concentrations of thiamine pyrophosphate and 2-(1,2-dihydroxyethyl)-thiamine pyrophosphate in mixtures.


2019 ◽  
Vol 79 (6) ◽  
pp. 1092-1101 ◽  
Author(s):  
Krishnendu Kumar Pobi ◽  
Biplab Mondal ◽  
Sumanta Nayek ◽  
Apurba K. Patra ◽  
Rajnarayan Saha

Abstract The present study is focused on the removal of Hg2+, Cd2+ and Pb2+ ions from aqueous solution using a tridentate chelating agent, 2-pyridyl-N-(2′-methylthiophenyl) methyleneimine (PMTPM); and applicability of such removal from industrial wastewater using PMTPM is also investigated. The results showed that the metal ions removal efficiency using PMTPM was in the order of Hg2+(99.46%) > Cd2+(95.42%) > Pb2+(94.54%) under optimum reaction conditions (L:M2+ = 3:1, pH = 9, time = 24 h, temp. = 30 °C). Formed chelated complexes such as [Hg(PMTPM)Cl2] (1), [Cd(PMTPM)Cl2] (2) and [Pb(PMTPM)Cl2] (3) were characterized by numerous spectroscopic tools and X-ray structure determination of a representative complex of Hg2+. In the X-ray structure of [Hg(PMTPM)Cl2], 1, the Hg2+ adopted a distorted tetrahedral coordination geometry surrounding two N donors of PMTPM and two chloride ions. A similar coordination geometry surrounding the respective metal centres in 2 and 3 was established. The thermogravimetric analysis (TGA) revealed a stability order of [Cd(PMTPM)Cl2] > [Hg(PMTPM)Cl2] > [Pb(PMTPM)Cl2]. Further the comparative metal leaching behaviour of these chelate complexes exhibited higher stability in alkaline solution than in acidic. Moreover, PMTPM was applied in real mixed industrial wastewater with alkaline pH, and adequate removals of toxic metals were achieved.


2016 ◽  
Vol 680 ◽  
pp. 52-55
Author(s):  
Hong Yan Guan ◽  
Jian Jun Ding ◽  
Zhong Bao Guo ◽  
Ming Yu Wang ◽  
Yi Fei Mei

The determination of chloride ions in concrete materials accurately is far and away crucial, since chloride ions can cause corrosion of steel and concrete cover off. The conventional potential method and silver nitrate titration method usually show features of simple operation and short duration, nevertheless, they are not suitable for accurate analysis for concrete attributing to their low accuracy and detection limit. In this paper, an ion chromatography method was presented to determine chlorine in concrete materials. Concrete samples were pre-processed and then extracted with distilled water. The extraction solutions were purified on a 0.22 μm filter membrane, an On Guard SPE-RP column and a SPE-H column sequentially for eliminating undissolved substance, organisms and metal ions before ion chromatographic analysis. The chromatographic separation was performed on a Dionex ICS-1000 Chromatographic using 25.0 mmol/L KOH solutions as mobile phase at 1.0 mL/min. Results show that the detection limit of the method was 0.004 mg/L. The linear relationship of the external Cl- standard solutions was 0.9994, and the sample analytical RSD was 0.44%.


1986 ◽  
Vol 5 (6) ◽  
pp. 393-406
Author(s):  
H. H. Telle

Selective photodissociation of diatomic molecules is used to prepare the separating species in a well defined quantum state with narrowly determined final kinetic energy of the particles. During the course of separation to products the repulsive potential is probed by a tunable dye laser, that is by induced absorption in case the dissociation proceeds on a potential leading to ground state products, or by induced emission or absorption for all other cases. The determination of interatomic potentials from the observed spectra is discussed.


Sign in / Sign up

Export Citation Format

Share Document