| SM ISO690:2012|
LUPASCU, Tudor; MITINA, Tatiana; BONDARENKO, Nadejda; GRIGORAS, Diana. Indirect atomic absorption determination of chloride ion in colored water. In: Ecological and environmental chemistry 2017The 6th International Conference. 2-3 martie 2017, Chișinău. Chisinau, Republic of Moldova: Academy of Sciences of Moldova, 2017, p. 113.
|Ecological and environmental chemistry 2017 2017|
Conferința "Ecological and environmental chemistry 2017" |
Chișinău, Moldova, 2-3 martie 2017
Underground waters of the south of Moldova are often colored. Determination of chlorides by titration (Mohr's method) in colored waters is challenging, especially if chloride content is low, and the sample cannot be diluted. For determination of chlorides in such water it is recommended to use other methods which are not affected by coloring of the sample. These are methods of capillary electrophoresis, chromatographic and indirect methods. We suggest indirect atomic absorption method of chloride ion determination by chrome. The idea of the method is obtaining chromyl chloride (СrO2Cl2) in the presence of concentrated sulfuric acid with its further extraction in carbon tetrachloride. It was followed by re-extraction, in the process of which, the obtained СrO2Cl2 during interaction with water, was hydrolized to produce chromic and hydrochloric acids, which remain in water phase. This step is necessary since halogen derivative solvents are not suitable for direct flame spraying because they do not get burned up entirely. In water solution, chrome was determined by the method of atomic absorption spectrometry using atomic absorption spectrometer AAS-1N in the flame acetylene-air at the wavelength 357, 9 nm. The accuracy of the method was confirmed using both model solution with a known concentration of chlorides and real water by the method "introduced-found". Recovery was 93%. The limit of the detection of the method, standard deviation and coefficient of variation were determined as well. A comparative analysis of the suggested method with the method of indirect determination by silver was carried out.