scholarly journals Determination of NH4+in Environmental Water with Interfering Substances Using the Modified Nessler Method

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Heonsang Jeong ◽  
Jongtaek Park ◽  
Hyunook Kim
Keyword(s):  
Polyvinyl Alcohol ◽  
Spectrophotometric Method ◽  
Water Samples ◽  
Essential Element ◽  
Environmental Water ◽  
High Concentration ◽  
Modified Method ◽  
Dispersing Agent ◽  
Treatment Facilities

Nitrogen is an essential element in the environment. If excess nitrogen includingNH4 +is present in water, however, it can result in algae blooming and eventually the destruction of the aquatic ecosystem. Therefore, the determination ofNH4 +in streams, lakes, and effluents of the treatment facilities has long been carried out. The Nessler method is the most common spectrophotometric method to measureNH4 +in water. However, the result of the method becomes inaccurate if there are interfering substances such as Cl2, Cl−, hardness-causing compounds (e.g., Mg2+), and Fe2+in target water samples. In this study, therefore, the traditional Nessler method has been modified to eliminate the effects of interfering substances; the so-called MS was added to water samples. In addition, the polyvinyl alcohol reagent as a dispersing agent was added to water samples to increase the sensitivity and reproducibility of the method. The modified method could successfully analyzeNH4 +of water samples even with the interfering substance at high concentration.

scholarly journals Spectrophotometric Determination of Low Levels of the Orthophosphate Anion as Molybdenum Blue using Sodium Thiosulphate Reducing agent

2020 ◽  
Vol 36 (6) ◽  
pp. 1066-1077
Author(s):  
Irene Nalumansi ◽  
Grace Birungi ◽  
Brenda Moodley ◽  
Emmanuel Tebandeke
Keyword(s):  
Spectrophotometric Method ◽  
Water Samples ◽  
Limit Of Detection ◽  
Environmental Water ◽  
Molar Absorptivity ◽  
Sodium Thiosulphate ◽  
Molybdenum Blue ◽  
Low Levels ◽  
Phosphomolybdenum Blue

A simple spectrophotometric method for the determination of low levels of the orthophosphate (PO43-) in environmental water systems is reported. The method is based the formation of the phosphomolybdate from the condensation of molybdate and orthophosphate in aqueous acid medium followed by reduction with sodium thiosulphate to form phosphomolybdenum blue. The system obeys Beer’s law at 880 nm (λmax) in the 0.005–0.06 mg P mL-1 phosphate concentration range. Molar absorptivity, Sandell’s sensitivity and correlation coefficient values for the determination were 57526 L mol-1 cm-1, 0.2835 μg cm-2 and 0.9948 respectively. The limit of detection was 2.213 x 10-3 mg P mL-1. The results of PO43- determination in water samples obtained using the spectrophotometric method developed in this study, compare favourably with those generated using the Murphy and Riley method which is commonly used for this analysis. Therefore, the study ably demonstrates the suitability of the present spectrophotometric method for analysis of the orthophosphate in environmental water samples.

scholarly journals Determination of essential and non-essential element contents of drinking water and baby water for infant’s nutrition

2021 ◽  
Vol 44 (1) ◽  
pp. 194-202
Author(s):  
Funda Demir ◽  
Meral Yildirim Ozen ◽  
Emek Moroydor Derun
Keyword(s):  
Water Samples ◽  
Infant Nutrition ◽  
Tap Water ◽  
Essential Element ◽  
Essential Elements ◽  
Local Market ◽  
Drinking Waters ◽  
Significant Difference ◽  
Element Contents

Abstract In this study, essential (Ca, Cr, Cu, Fe, K, Mg, Na, P, Zn), and non-essential (Al, Ni, Pb) element contents of the drinking and baby water samples which are sold in the local market and tap water samples in Istanbul were examined. It was determined that elements of Cr, Cu, Fe, P, Zn, Al, and Ni were below detection limits in all water samples. Among the non-essential elements analyzed in water samples, Pb was the only detected element. At the same time, the percentages that meet the daily element requirements of infants were also calculated. As a result of the evaluations made, there is no significant difference in infant nutrition between baby waters and other drinking waters in terms of the element content.

scholarly journals Fast UHPLC-MS/MS for the Simultaneous Determination of Azithromycin, Erythromycin, Fluoxetine and Sotalol in Surface Water Samples

2021 ◽  
Vol 11 (18) ◽  
pp. 8316
Author(s):  
Mira Azzi ◽  
Sylvain Ravier ◽  
Assem Elkak ◽  
Bruno Coulomb ◽  
Jean-Luc Boudenne
Keyword(s):  
Surface Water ◽  
Simultaneous Determination ◽  
Surface Waters ◽  
Water Samples ◽  
High Performance ◽  
Chemical Properties ◽  
Environmental Water ◽  
Butyl Ether ◽  
Flight Mass Spectrometry

Chromatographic development for the determination of pharmaceuticals in environmental water samples is particularly challenging when the analytes have significantly different physico-chemical properties (solubility, polarity, pKa) often requiring multiple chromatographic methods for each active component. This paper presents a method for the simultaneous determination of azithromycin, erythromycin (antibiotics), fluoxetine (anti-depressant) and sotalol (b-blocker) in surface waters by ultra-high-performance liquid chromatography coupled with ultra-high-resolution time-of-flight mass spectrometry. These pharmaceuticals—presenting a broad spectrum of polarity (0.24 ≤ log Kow ≤ 4.05)—were separated on a C-18 analytical column, after a simple filtration step for freshwater samples or after a liquid–liquid extraction with Methyl-tertio-butyl ether (MTBE) for seawater samples. The optimized separation method (in terms of nature of column and eluent, elution gradient, and of mass spectrometric parameters), enable one to reach limits of detection ranging between 2 and 7 ng L−1 and limits of quantification between 7 and 23 ng L−1 for the four targeted molecules, within a three minute run. This method was validated using samples collected from three different surface waters in Lebanon (freshwater and seawater) and analytical results were compared with those obtained in surface waters sampled in a French river, equivalent in terms of human activities. Using this method, we report the highest concentration of pharmaceuticals found in surface water (up to 377 ng L−1 and 268 ng L−1, respectively, for azithromycin and erythromycin, in the Litani river, Lebanon).

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