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The purpose of this study was to monitor and record the specific characteristics and properties of the Arges River water in the Budeasa Reservoir (the principal water resources of municipal tap water of the big Romanian city Pitesti and surrounding area) for a period of 5 years (2005-2009). The monitored physical and chemical parameters were turbidity, pH, electrical conductivity, chemical oxygen demand, 5 days biochemical oxygen demand, free dissolved oxygen, nitrite, nitrate, ammonia nitrogen, chloride, total dissolved iron ions, sulfate, manganese, phosphate, total alkalinity, and total hardness. The results were discussed in correlation with the precipitation values during the study. Monthly and annual values of each parameter determined in the period January 2005-December 2009 were used as a basis for the classification of Budeasa Reservoir water, according to the European legislation, as well as for assessing its quality as a drinking water supply. Principal component analysis and Pearson correlation coefficients were used as statistical procedures in order to evaluate the data obtained during this study.

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A new HPLC method was developed for the simultaneous determination of aminophenol isomers by means of a mixed-mode stationary phase containing both SCX and C18 moieties. All factors influencing the separation were discussed and optimized. The chromatographic conditions for the separation of aminophenols are the stationary phase duet SCX/C18, the mobile phase of aqueous phosphate buffer (pH 4.85):methanol = 85:15 (v/v) delivered with a flow rate of 1 mL/min and a detection at 285 nm. The method proposed was validated in terms of linearity, limits of detection and quantification, accuracy and precision. The HPLC method elaborated here was applied with good results on river water samples. In order to survey the quality of surface rivers entered in treatment plants which deliver water for Bucharest, two major rivers were included in a monitoring program which last more than 1 year.

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Determination of acetaminophen and its main impurities: 4-nitrophenol, 4'-chloroacetanilide, as well as 4-aminophenol and its degradation products, p-benzoquinone and hydroquinone has been developed and validated by a new high-performance liquid chromatography method. Chromatographic separation has been obtained on a Hypersil Duet C18/SCX column, using gradient elution, with a mixture of phosphate buffer (pH = 4.88) and methanol as a mobile phase. Analysis time did not exceed 14.5 min and good resolutions, peak shapes and asymmetries have resulted. The linearity of the method has been tested in the range of 5.0-60 µg/mL for acetaminophen and 0.5-6 µg/mL for the other compounds. The limits of detection and quantification have been also established to be lower than 0.1 µg/mL and 0.5 µg/mL, respectively. The method has been successfully applied for the analysis of commercial acetaminophen preparations.

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A simple, sensitive and reliable HPLC-FLD method for the routine determination of 4-nonylphenol, 4-NP and 4-tert-octylphenol, 4-t-OP content in water samples was developed. The method consists in a liquid-liquid extraction of the target analytes with dichloromethane at pH  3.0-3.5 followed by the HPLC-FLD analysis of the organic extract using a Zorbax Eclipse XDB C8 column, isocratic elution with a mixed solvent acetonitrile/water 65:35, at a flow rate of 1.0 mL/min and applying a column temperature of 40°C. The method was validated and then applied with good results for the determination of 4-NP and 4-t-OP in Ialomita River water samples collected each month during 2006. The concentration levels of 4-NP and 4-t-OP vary between 0.08-0.17 µg/L with higher values of 0.24-0.37 µg/L in the summer months for 4-NP, and frequently <0.05 µg/L but also between 0.06-0.09 µg/L with higher values of 0.12-0.16 µg/L in July and August for 4-t-OP and were strongly influenced by sesonial and anthropic factors. The method was also applied on samples collected over 2 years 2007 and 2008 from urban wastewaters discharged into sewage or directly into the rivers by economic agents located in 30 Romanian towns. Good results were obtained when the method was used for analysis of effluents discharged into surface waters by 16 municipal wastewater treatment plants, during the year 2008.

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The level of three alkylphenols (APs) 4-nonylphenol, 4-octylphenol and 4-tert-octylphenol was monitored in various water samples using a new developed and validated HPLC method. The HPLC method employed a column with a mixed-mode stationary phase (C18/SCX) using a mobile phase of water to methanol = 15:85 (v/v) delivered at a flow rate of 1 mL/min at room temperature. Both diode array, DAD and fluorescence, FLD detectors were employed. The method is linear when APs concentration ranged from 0.025 to 0.5 µg/mL with a DAD detection at 279 nm and between 0.0008 and 0.1 µg/mL when the detection was made by FLD (excitation at 220 nm, emission at 315 nm). The limit of detection and limit of quantitation for alkylphenols were found to be 5 and 15 ng/mL, respectively (detection by DAD). The method was employed with good results for the determination of APs in the presence of polycyclic aromatic hydrocarbons in various water samples.

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Romania is one of the countries that have natural arsenic groundwater problems. This paper presents the results of a study of arsenic concentration monitoring in natural mineral waters collected from 23 sampling sites located in the northern, central, and western regions of Romania. The sampling sites are both natural springs and drilled wells. The graphite furnace atomic absorption spectrometry was used for arsenic content determination. The Piper's classification principle was applied in order to find out the hydrochemical type of the analyzed waters. Depending on the concentration of arsenic, the water analyzed can be classified into three main categories: (1) mineral natural waters containing less than 10 µg/L arsenic, (2) mineral natural waters containing arsenic at concentrations several times higher than the limit of 10 µg/L but less than 100 µg/L, and (3) mineral natural waters containing arsenic at concentrations of ten to a hundred times higher than the allowed limit of 10 µg/L. The last-mentioned waters are of bicarbonatate sodium type and were sampled from seven sources only, being prohibited for human and animal use.

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In this paper, the cadmium distribution in Certej River sediments in an area seriously affected by intense mining activities has been studied. The main objective of this study was the evaluation of partition of this metal into different operational defined fractions by sequential extractions. Community Bureau of Reference (BCR) sequential extraction was used to isolate different fractions. The sediment quality was assessed both upstream and downstream the pollution input points, along the Certej River, in order to reveal a possible accumulation of cadmium in sediments and the seasonal changes in cadmium concentrations in BCR sediment phases. Our results reveal that most of the cadmium content is divided between both the soluble and iron and manganese hydrated oxide fractions. Based on total cadmium concentrations in sediments, the enrichment factors were estimated using aluminum as normalizing element and the regression curve Cd/Al corresponding to the geochemical background of the studied area.

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In the present study, the BCR (Community Bureau of Reference) sequential procedure has been applied to determine the zinc partition in sediments taken from a river situated in the Southwest of Romania, in a region subject of intense mining activities. The sampling was performed during three sampling expeditions, organized in the spring, summer, and autumn, 2007. The zinc concentration in different fractions was normalized, its concentration being related to the concentrations of some metals (such as Al or Fe) that are naturally present in sediments. The zinc-contaminated sediments from the investigated area have been evaluated by means of combining the analysis data from the BCR sequential extraction with the normalization to the Al content. The most important zinc collector in the samples taken during the three sampling expeditions is the easily soluble fraction, next being amorphous iron and manganese hydrated oxides fraction, followed by organic matter fraction.

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This paper reports the results obtained for the determination of Ba concentrations in mineral groundwater samples collected from drilled outlets located in the counties of Covasna and Harghita (34 sampling points), in five expeditions (spring, summer, and autumn), during 3 years: 2005, 2006, and 2007. The experimental data show that there are some sampling sites in which the barium concentration exceeds 1 mg/L, which is the maximum concentration admitted for barium. These mineral natural waters could be used only for therapeutic purposes. All other analyzed natural mineral waters are proper as both drinking and therapeutic water. By means of a principal component analysis a statistical approach was performed, using the data obtained during those analyzing processes. The distribution of the water saturation indexes with respect to a series of mineral species (alstonite, barite, barytocalcite, nitrobarite, sanbornite, and witherite) suggests that barium tends to remain in solution as ionic species in different concentrations and to be further carried away as such.

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This paper presents the development, optimization and validation of a new HPLC method used for the separation and determination of zearalenone, ZON, and its metabolites in biological samples of Leghorn broiler. ZON and its metabolites can be separated with good resolution in 11 min, using a Hypersil Gold C18 column, a mobile phase mixture of 50 mM aqueous ammonium acetate:acetonitrile:methanol, 45:8:47 (v/v/v), flow rate 1 mL/min and column temperature 40 degrees C. Based on the results obtained by this method applied on biological samples one can conclude that liver is the site for zearalenone localization and detoxification. Influence of zearalenone on the nutritional properties of broiler meat (weight variation, gross chemical composition, fatty acids profile of the meat) was studied, also. Results obtained during 4 days of treatment with ZON showed minimal or no effects of the dietary zearalenone on broiler meat nutritional quality.

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A method for the determination of total selenium in wheat and wheat flour using graphite furnace atomic absorption spectrometry (GFAAS) with palladium/ascorbic acid as a chemical modifier was studied. The effects of nickel nitrate, palladium/ascorbic acid, and palladium/magnesium nitrate as chemical modifiers on the sensitivity in the determination of selenite, selenate and selenomethionine by GFAAS were compared. The palladium/ascorbic acid modifier was used for the determination of total selenium in wheat and wheat flour, because the oxidation states of the selenium ion are not important in the determination. The detection limit was estimated to be 1 microg L(-1) (calculated as 3sigma of the blank); the calibration curve was linear for the concentration range 5 - 50 microg L(-1) and the recovery range was 96.66 - 101.80%. The optimal ashing and atomizing temperatures were 1300 degrees C and 2250 degrees C, respectively. The proposed method was successfully applied to the determination of total selenium in wheat and wheat flour.

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This study was conducted in a southeast region of Romania, known to be selenium (Se) deficient. The fluorimetric method for the determination of Se in biological samples was used in a study on the serum Se content in time in a group of 10 cows with a high milk yield and in their calves. The same cows were sampled antepartum (late pregnancy) and postpartum (1, 7, 21, 30, and 60 d), and the calves were sampled on d 1 of life and 7, 21, 30, and 60 d postcalving. Colostrum and milk samples were also collected and analyzed at the same times. Throughout the study, the serum Se content in both the cows and the calves was below the reference values (0.040-0.100 microg/mL), except the control conducted 7 d postpartum, for which it was 0.044 +/- 0.017 and 0.023 +/- 0.007 mg/mL in cows and calves, respectively. The most significant drops were recorded 21 (p<0.01) and 60 d postpartum (p<0.05). The colostrum Se was higher (0.036 +/- 0.022 microg/mL), decreasing progressively throughout the study to the normal low limit (0.005 microg/mL). The milk Se concentration was lower by approx 78% than the colostrum one on d 1 postcalving. These data demonstrate the course of hyposelenosis both in the cows and their calves. The maternal body proved to "mobilize," even in case of deficiency, important Se amounts in the colostrum, during the first days in particular.

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One hundred and eighty-five samples of feeds (hays, green plants, and concentrate feed) from households covering 41 localities in Dobrudja, a southeast region of Romania, were collected and analyzed for selenium (Se) content by spectrofluorometry with 2,3-diaminonaphthalene. Only 6.5% of the samples analyzed were, in terms of the feed Se content, considered appropriate (i.e., 0.15-0.30 ppm), within the normal range. The remaining 93.5% proved to be Se deficient; the results fell into the 0.001-0.150 ppm range. Consequently, the samples were divided into three deficiency groups based on the content recorded as follows: severe for 3.2% (Se below 0.01 ppm), critical for 84.9% (Se in the 0.01-0.1 ppm range), and marginal for 5.4% (Se in the 0.1-0.15 ppm range). Conclusively, the Dobrudja feeds may be said to be generally Se deficient, which requires prophylactic and therapeutic measures to correct animal selenium deficiency.

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A first derivative spectrometric method has been developed for the determination of the para-aminobenzoic acid (PABA), a related substance and degradation product of the local anesthetic procaine hydrochloride (PH). The wavelength selected for the determination of para-aminobenzoic acid in the presence of procaine was 290 nm. At this wavelength the calibration graphs relating the amplitude of the signals to the concentration of para-aminobenzoic acid were linear up to 10 mg L(-1). The detection limit of para-aminobenzoic acid was 0.70 mg L(-1). The method is simple and rapid and does not require preliminary treatment of the sample. The method was validated.