2.2. Samples preparation

renewable natural resource, vulnerable, and confined; indispensable for life and society (its physical dimension); raw material for productive activities, source of energy, and transport route (its economic dimension); critical element in maintaining the ecological balance (its environmental dimension). The European Union (EU) Water Framework Directive (WFD) [2] establishes a framework for the protection of waters and consists of a new vision for the management of water resources in Europe. Mainly sustained on ecological elements, the ultimate objective of the WFD is the achievement of at least "a good ecological quality status"

According to the estimation of the World Health Organization, about two‐thirds of diseases are caused by the polluted water. Through its accession to the EU, Romania has undertaken to comply with the European regulations on water quality [3]. Within the United Nations Environment Programme, which supports the surveillance of water quality in freshwater ecosystems worldwide, by its global system of environmental monitoring (GEMS)/Water Global Network [4], the determination of heavy metals concentration is mandatory when the water

The proposed subject represents a highly current field; the concentration of heavy metals in water being an intensive subject researched worldwide [5–7]. Some researchers have determined metal concentrations in water, sediment, plant; others have studied the metals effect on live organisms [8–10]. Heavy metals are seen as potential hazard for human health and ecosystem as they cannot be degraded, being continuously deposited and incorporated in water, sediments, soil, and vegetation. Anthropogenic activities may lead to important accumulations of toxic metals into the environment; therefore, the assessment of contamination degree in the aquatic and terrestrial environments by means of elemental analysis became a

2. Sample preparation and analytical methods selection for analyzing

Somes is a transboundary catchment located in the north‐western Romania. Its main sources of water are the surface waters, reservoirs, and ground waters. The overall water resources in the basin are theoretical about 4.348 billion m3 (of which 4.012 billion m3 coming from surface waters and 336 million m3 of groundwater), but only 21.7% are technically usable. In this region, there

The main objective of this study was to characterize the surrounding areas of raw water accumulations from the catchment, in terms of its content in heavy metals and rare earth, correlated with the supply mechanism of these surface waters. Thus, an assessment of the quality of surface flowing waters, during 2009–2011, was performed. Waters from eight surveillance sections were sampled: the Gilau dam (Area 1); the Somes Cald River (Area 2); the end of Gilau Lake intersection with the Somes Cald River (Area 3); the Somes Cald Lake (Area 4);

).

), Tarnita (2.2 km2

),

for all surface waters.

270 Water Quality

quality is assessed.

2.1. Study area

Somes Cald (0.8 km2

common monitoring activity of our days.

contaminant elements in environmental samples

are 23 reservoirs with areas over 0.5 km2 such as the Gilau Lake (0.67 km2

), and Fantanele‐Belis (8.15 km2

Water samples were collected in high‐density polyethylene containers previously washed in a solution of 10% nitric acid in an ultrasonic bath for 15 min followed by repeated rinsing with bi‐distilled water and finally rinsed with ultrapure water (resistivity 18.2 MΩ cm−<sup>1</sup> ). Until sampling, the containers were kept in sealed polyethylene bags. Water samples were stabilized with ultrapure nitric acid (0.5% HNO3).

Samples of sediment, soil, and vegetation require a digestion process to bring them into solution. For inductively coupled plasma mass spectrometry (ICP‐MS) analysis, the digestion process should satisfy some conditions: the entire quantity of sample has to be dissolved, only ultrapure reagents must be used, any loss of analyte has to be avoided, the vessels in which the sample is kept must not react with the sample or the reagents used for the digestion, and the entire process should be fast and reliable. The samples were lyophilized, and then, 0.1 g aliquot of each sample was weighed. These aliquots were then digested in an acid mixture (3 ml HNO3 60% + 2 ml HF 40%) at high pressure and temperature. After cooling, the liquid was transferred through a semi‐automatic pipette in a 50 cm<sup>3</sup> volumetric flask of high‐density polyethylene and was brought to the required volume with ultrapure water.
