Pollution of drinking and natural waters is the fundamental environmental problem. Due to the rapid development of human economic and industrial activity, monitoring of the environmental situation is necessary. Total Reflection X-ray Fluorescence Analysis makes it possible to determine the elemental composition of water quickly and accurately for a large number of elements simultaneously. The work is devoted to the study of water sources in the southwest district of Moscow: Ramenka and Rogachevka rivers and the drinking water source in the park of the 50th anniversary of the October. During the work, suitable conditions were found that make it possible to perform the analysis quickly (the analysis time does not exceed 10 min. for one sample) and to determine a number of elements at the macro-, micro- and trace levels. The obtained results are compared with the current Russian sanitary standards.
The human impact on the environment leads to a change in the chemical composition
of water used in everyday life, compared with its natural composition. Water is used
by humankind everywhere, including cooking and drinking, so attention should be
paid to water analysis. One of the most effective modern methods for determining the
elemental composition of water is Total Reflection X-ray Fluorescence Analysis
(TXRF). The method allows to determine small amounts of substance (less pg in
absolute values) with low detection limits (down to ng/l for liquid samples)
The purpose of this work is to determine the elemental composition of the natural waters of the southwest district of Moscow: Ramenka and Rogachevka rivers and the drinking water source in the park of the 50th anniversary of the October using the TXRF method, as well as comparing the data obtained with the Russian sanitary standards.
Several samples from water system of Moscow southwest district were taken for the analysis. The pond in the flow of Ramenka river (sample 1), Ramenka river itself (sample 2), Rogachevka river (sample 3), which is a confluent of Ramenka, Ramenka river after the confluence of both rivers (sample 4), the artesian source of drinking water (sample 5) and also sample of the snow from a slope of Ramenka river. The sampling scheme is shown on Fig. 1. 3
Water samples were acquired in plastic bottles. The measurements were carried out on the TXRF spectrometer S2 PICOFOX (Bruker Nano GmbH, Germany) using quartz reflectors. The excitation was performed by Mo Kα (17.5 keV) radiation. The time of the spectrum acquisition is 250 s. Gallium solution with the concentration 1000 mg/l is used as an internal standard. This element is easily detected by TXRF. It does not present in sample and does not cause spectral interference with elements in sample. The volume of the aliquots was chosen to be 0.5 ml, the volume of the internal standard solution was 5 µl. The volume of the analyzed solution deposited on the reflector is 1-2 µl. In water samples S, Cl, K, Ca macroelements, Fe, Cu, Zn, Br, Sr microelements and trace elements Ti, Mn, Ba, Pb were detected. Analysis results are listed in Table 1.
Analysis of water reservoirs (samples 1-4) shows that water from Ramenka river (sample 2) has the highest mineralization of all investigated water samples (fig. 2). The highest concentration of such elements as S, Cl, K, Ca, Cu, Zn, Br was found in this sample. At the same time the content of same elements is much lower in the pond from which the river flows (sample 1). It is presumably due to the sedimentation of water followed by transition of elements to muddy sediment at the bottom of the reservoir.
In the confluent of the Ramenka river – Rogachevka river, the content of elements of S, Cl, K, Ca, Cu, Zn, Br is also lower than in Ramenka (sample 3). The mineralization of water after confluence of Rogachevka to Ramenka decreases due to dilution.
Waters investigated meet the standards set for a household water (see Table 2), with the exception of the Ramenka river (sample 2), in which chlorine content is exceeds the maximum allowed concentration (488 mg/l).
Sample 5 – drinking water sample was also compared with standards for drinking water. As can be seen from Tables 1, 2, content of (S, Cl, Ca, Fe, Cu, Zn, Ba) is within the permissible concentrations. In addition to these elements, traces of titanium and lead were found in drinking water in an amount several times lower than maximum allowed concentrations. 0.1 0.1 0.01 0.1 Acknowledgment. This work was financially supported by the Russian Science Foundation (project no. 14-23-00012).