Water quality is assessed through the biological, physical and chemical parameters. The limits of these parameters that are harmful to human health have been established at national or international level (WHO, EPA, MECC) by various laws, regulations, normative. An efficient and simplified to express the quality of water for consumption is given by the water quality index. It reflects the quality of water in a single value by comparing data obtained from the investigation of a number of physico-chemical and bacteriological parameters with existing limits. This number is placed on a relative scale to justify the quality of water in categories ranging from very poor to excellent. In this study are discussed various water quality indices used to assess the quality of drinking water (surface water). National and international agencies involved in assessing water quality and pollution control defines different quality criteria used for drinking water which is why there are many water quality specific indices for each region or area. In this context, it will present a comparative study of the most important quality indices used to assess water quality worldwide.

The presence of pharmaceuticals in the aquatic ecosystem has received great attention from the scientific community in the last decades, due to their potential impact on living organisms. This paper presents a short review of the results of investigations performed by INCD-ECOIND concerning the occurrence of 32 pharmaceutical compounds belonging to important therapeutic classes and 2 disinfectants along the Danube River and its tributaries. Grab water samples were collected from multiple points along the River (10 sites) and from 2 locations for each of the tributaries Jiu, Olt and Argeș, upstream and downstream of large cities. All samples were quantified via solid phase extraction, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results of these studies show that various pharmaceutical compounds are present in the dissolved water phase of the Danube River and its tributaries in low to moderate amounts with variation due to season and location.

A simple, reliable and accurate HPLC/CAD method was developed for the determination of anionic (sodium dioctyl sulfosuccinate and sodium 1-dodecane sulfonate), amphoteric (CHAPS (3-[(3-Cholamidopropyl) dimethylammonium]-1-propanesulfonate hydrate)) and cationic (benzethonium chloride) surfactants mixture from surface water samples. The chromatographic analysis was performed on an Acclaim Surfactant Plus (150 x 3.0 mm, 3 mm d.p.) column acquired from Thermo Scientific, kept at 300C. All experiments were performed in gradient elution conditions at a flow-rate of 0.6 mL/min. Mobile phase composition was a mixture of acetonitrile (A) and 0.1 M ammonium acetate solution acidified to pH 5 with acetic acid (B). The limit of detection (LD) were 20 mg/L for anionic surfactants and 30 mg/L for cationic and amphoteric surfactants. The calibration curves were linear between 15 mg/L � 110 mg/L, with R2 values above 0.992 for all surfactants. Solid phase extraction (SPE) using polymeric (Strata X) cartridges has been applied to extract and concentrate the target analytes from the synthetic samples. Surfactants recoveries after SPE procedure were situated between 91.5�94.6%. Intra-day and inter-day precision (RSD%) were situated between 4.0 � 7.7% and 7.5 � 11.7%, respectively. Limit of quantitation (LQ) was lower than 80 mg/L for anionic surfactants and 90 mg/L for cationic and 100 mg/L for amphoteric surfactants. The new sensitive and selective HPLC/CAD developed method allows simultaneous determination of anionic, amphoteric and cationic surfactants mixture from environmental samples (surface water).

The fate of organochlorine compounds in soil ecosystem is shaped by their physical-chemical properties and by environmental conditions. The high persistence of polychlorobiphenyls (PCBs) in soil is given by a slow degradation which varies from months to years (the half-life of PCB 28 is 10.9 years, and PCB 52, 11.2 years). Due to high lipophilicity, these carcinogenic compounds can be easily uptaken by plants and transferred to the food chain. The widespread use of medicinal plant, Mentha Piperita, in pharmaceutical and food industry represents a risk of contamination and pollution. Through laboratory studies, we worked to identify the chemical behavior in soil and plants of some PCB congeners: 28, 52, 138, 153 and 180). The compounds mobility from soil to the roots and then through plant was monitored for 5 weeks. By optimizing the analytical method the contaminants were determined from soil and plant with good recoveries and with reduced limit of detection, below 0.01 mg/kg. It was reported that usually are uptaken into the plant high chlorinated PCBs like PCB 153 and PCB 180 but this study shows that after 5 weeks of PCB application, the concentration of PCB 28, a trichlorobiphenyl, is increasing. Fortunately, calculating the bioconcentration factor (BCF) of the selected PCBs in roots, it was shown that is similar to BCF of other plants like poplar and zucchini. The obtained value of 0.2 is assessed as being low.

A liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) method was developed and validated for the simultaneous determination of six organic compounds (2-hydroxy benzophenone, 4hydroxy benzophenone, 2,2',4,4'-tetrahydroxy benzophenone, 2,4-dyhydroxy benzophenone, 4,4'dyhydroxy benzophenone, 2,2'-dyhydroxy-4-methoxy-benzophenone) used as UV filters in personal care products used to protect against UV radiation. The major concern about this type of pollutants is due to their persistence and bioaccumulation potential in the environment and aquatic organisms and for their endocrine disruptor properties. Solid phase extraction was used for sample preparation, followed by liquid chromatography tandem mass spectrometry analysis. Benzophenone derivatives were analyzed on a Phenomenex Luna C18 column (150 x 2.0 mm, 3.0 µm) with the mobile phase run in gradient mode with a mixture of aqueous 0.1% formic acid and acetonitrile as the mobile phase components (at a flow rate of 0.2 mL/min). MS detector response was linear, on the tested concentration domain from 1 to 100 μg/L with correlation coefficient R 2 > 0.998. The recoveries of benzophenone derivatives after solid phase extraction procedure from surface water was found to be >81% for surface water and higher than 79% for wastewater matrix. The standard deviation values for intra-day precision were situated between 7.67% and 9.88% for lower concentration and 7.27% and 8.86% for higher concentration respectively. The limits of quantitation were calculated for both environmental water matrices (1.6-4.1 ng/L for surface water and 3.3-8.2 ng/L for wastewater). This method can be applied for benzophenone derivatives detection in real environmental samples.