scholarly journals A Fluorimetric Method Based on an Imidazole Compound for Cu2+ Determination in Tap Water

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Zafer Ocak
Keyword(s):  
Standard Deviation ◽  
Water Samples ◽  
Fluorescence Spectra ◽  
Tap Water ◽  
External Calibration ◽  
Relative Standard ◽  
Sensor Properties ◽  
Detection And Quantification ◽  
Imidazole Compound

Ion sensor properties of 4-(1-(4-hydroxy-3-methoxybenzyl)-1H-benzo[d]imidazol-2-yl)-2-methoxyphenol (L) in acetonitrile-water (1 : 1) were evaluated by fluorescence spectrometry. Pronounced quenching in the fluorescence spectra of the ligand was only observed for the Cu2+ ion among many metal ions. Linear fluorescence responses of the ligand at 360 nm as the function of the Cu2+ concentration were used for the determination of the Cu2+ ion in spiked tap water samples. Recovery values (R%) were satisfactory, and relative standard deviation (RSD%) was below 5.00 in intraday and interday measurements. Detection and quantification limits were 0.28 and 0.84 μg/L, respectively. The assay based on external calibration only took a few minutes.

Synthesis and Application of p-Carboxyarsenazo for Spectrophotometric Determination of Cu(II) in Environment Water

2013 ◽  
Vol 830 ◽  
pp. 298-301 ◽  
Author(s):  
Lin Gao ◽  
Yan Hua Li ◽  
Sheng Jie Chen ◽  
Fang Chen ◽  
Yuan Fang Zhang ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Water Samples ◽  
Absorption Maximum ◽  
High Sensitivity ◽  
Molar Absorptivity ◽  
Buffer Solution ◽  
Relative Standard ◽  
Sensitivity And Selectivity ◽  
Color Reagent

p-Carboxyarsenazo (CASA) color reagent was synthesized by simple diazotization reaction, and the chromomeric reaction between CASA with Cu(Ⅱ) has been studied by spectrophotometry. In pH=4.6 NaAc-HAc buffer solution, Cu(Ⅱ) reacted with CASA to form a red complex and exhibits an absorption maximum at 614 nm, Beer’s law is obeyed for 0-160 μg/L of copper in solution, the apparent molar absorptivity obtained is 1.57×104 L/(mol.cm), and the relative standard deviation (R.S.D.) is 1.6%. The proposed method exhibited high sensitivity and selectivity for Cu(Ⅱ). The results obtained by this method in the determination of environment water samples were accurate, sensitive and repeatable

scholarly journals A New Spectrophotometric Method for Hydrogen Sulphide Through Electrolytically Generated Mn(III) WithO-Tolidine

2008 ◽  
Vol 5 (1) ◽  
pp. 93-99 ◽  
Author(s):  
M. S. Suresha ◽  
Mansour S. Abdul Galil ◽  
Mahadevaiah ◽  
M. A. Sathish ◽  
M. S. Yogendra Kumar ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Hydrogen Sulphide ◽  
Spectrophotometric Method ◽  
Water Samples ◽  
Molar Absorptivity ◽  
Official Method ◽  
Color Intensity ◽  
Orange Yellow ◽  
Relative Standard

A simple, sensitive and economical spectrophotometric method for the determination of hydrogen sulphide is developed. The method is based on a redox reaction in that Mn(III) generated electrolytically is taken in excess, which is oxidizing a known but a less quantity of hydrogen sulphide and the unreacted oxidant will oxidize furthero-tolidine to produce an orange yellow quinonediimine absorbing cation (λ max. 455 nm). Therefore, in principle, the decrease in color intensity of the absorbing system is proportional to the concentration of hydrogen sulphide. The stoichiometry between Mn(III) ando-tolidine and stability constant of the complex were determined by Job's continuous method, the corresponding values were found to be 2:1 and 1.42X105Lmol-1. The system was obeying Lambert-Beer's law in the range 0.2-1.4 μg mL-1of hydrogen sulphide. Molar absorptivity, correlation coefficient and Sandell's sensitivity values were also calculated and found to be 4.2062X103L mol-1cm-1, 0.999 and 0.0012 μg cm-2respectively. The method was employed for the determination of hydrogen sulphide in water samples. The results obtained were reproducible with acceptable standard deviation 0.01-0.068 and relative standard deviation, less than 3.21%. For a comparison, hydrogen sulphide present in water samples were also determined separately following the methylene blue official method. The results of the proposed method compare well with the official method.

Determination of Trace Amounts of Lead Using the Flotation-spectrophotometric method

2011 ◽  
Vol 6 ◽  
pp. ACI.S5948b
Author(s):  
Sabah Shiri ◽  
Ali Delpisheh ◽  
Ali Haeri ◽  
Abdolhossein Poornajaf ◽  
Babak Golzadeh ◽  
...  
Keyword(s):  
Water Samples ◽  
Sea Water ◽  
Tap Water ◽  
Molar Absorptivity ◽  
Alizarin Yellow ◽  
Low Concentrations ◽  
Relative Standard ◽  
Seawater Samples ◽  
Almost All

The present study describes a simple and highly selective method for separation, preconcentration and spectrophotometric determination of extremely low concentrations of lead. It is based on flotation of a complex of Pb2+ ions and Alizarin yellow between aqueous and n-hexane interface at pH = 6. The proposed procedure is also applied for determination of lead in both tap water and prepared sea water samples. Beer's Law was obeyed over the concentration range of 3.86 × 10-8 To 8.20 × 10-7 molL-1 (8-170 ngmL-1) with an apparent molar absorptivity of 1.33 × 106 molL-1 cm-1 for a 100 mL aliquot of the water sample. The detection limit (n = 10) was 8.7 × 10-9 molL-1 (1.0 ngmL-1) and the Relative standard deviation (R.S.D), (n = 10) for 7.2 × 10-7 molL-1 (150 ngmL-1) of Pb (II) was 4.36%. A notable advantage of the method is that the determination of Pb (II) is free from the interference of almost all cations and ions found in the environment and waste water samples. The determination of Pb (II) in tap and synthetic seawater samples was also carried out by the present method. The results were satisfactorily comparable so that the applicability of the proposed method was confirmed to the real samples.

scholarly journals Determination of Bentazone in Waters by Solid-Phase Spectrofluorimetry

1996 ◽  
Vol 79 (2) ◽  
pp. 567-570 ◽  
Author(s):  
José Luis Vilchez ◽  
Diego Torres-Bustos ◽  
Rosario Blanc ◽  
Alberto Navalón
Keyword(s):  
Standard Deviation ◽  
Detection Limit ◽  
Relative Standard Deviation ◽  
Natural Water ◽  
Water Samples ◽  
Solid Phase ◽  
Excitation Wavelength ◽  
Relative Standard ◽  
Sensitive Method

Abstract A sensitive method for determining trace amounts of bentazone was developed. The method is based on solid-phase spectrofluorimetry. Bentazone was fixed on a dextran-type anion-exchange gel, and the fluorescence of the gel, packed in a 1 mm thick quartz cell, was measured directly at an excitation wavelength of 338 nm and an emission wavelength of 436 nm by using a solid-phase attachment. The applicable concentration range was 2.0–120.0 μg/L, with a detection limit of 0.4 μg/L. The relative standard deviation at the 30.0 μg/L level was 1.2%. The method was used to determine bentazone in natural water samples. Recoveries were 96.0–102.5%.

scholarly journals Determination of OCPs and PCBs in environmental water samples by GC-DLLME optimized by Response Surface Methodology

2019 ◽  
Vol 20 (46) ◽  
pp. 13-23
Author(s):  
Dekun Hou ◽  
Otgonbayar Khureldavaa ◽  
Fujin Zhang ◽  
Jiang He ◽  
Badgaa Amarsanaa
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Lake Water ◽  
Water Samples ◽  
Tap Water ◽  
Environmental Water ◽  
Enrichment Factors ◽  
Environmental Water Samples ◽  
Relative Standard

A new sample preparation procedure to determine seven organochlorine pesticides and seven polychlorinated biphenyls in environmental water samples by using a combination of ultrasonic-assisted solvent extraction and dispersive liquid-liquid micro-extraction was established, and the extracted analytes were analyzed by gas chromatography coupled with electron capture detector. Some parameters influencing the extraction efficiency were studied and optimized utilizing response surface methodology. Under the optimum extraction conditions, the method showed wide linear ranges with r2 > 0.9989 and low limits of detection and quantification between 0.16 ~ 2.17 μg/L and 0.53 ~ 7.16 μg/L, respectively. Enrichment factors (EF) were high and ranged from 63 to 116. Relative standard deviations (RSDs) for the extraction of 25 μg/L of each selected OCPs and PCBs were less than 10.2 %. The proposed method was successfully used for targets contaminations determination in different water samples. α-HCH, β-HCH and p,p’-DDE were found in lake water closed to farmland with concentrations of 2.56 μg/L, 4.44 μg/L and 4.74 μg/L, respectively, and other OCPs and PCBs were not found in the corresponding water samples. The relative recoveries of OCPs and PCBs from tap water, river water and lake water at spiking levels of 10 μg/L were in the range of 81.9 ~ 109.7 %, within a relative standard deviation of 1.7 ~ 11.8 %. The results revealed that the proposed method was well suited for the determination of trace amounts of target contaminations in liquid samples.

scholarly journals Determination of Trace Amounts of Lead Using the Flotation-spectrophotometric method

2010 ◽  
Vol 5 ◽  
pp. ACI.S5948 ◽  
Author(s):  
Sabah Shiri ◽  
Ali Delpisheh ◽  
Ali Haeri ◽  
Abdolhossein Poornajaf ◽  
Babak Golzadeh ◽  
...  
Keyword(s):  
Water Samples ◽  
Sea Water ◽  
Tap Water ◽  
Molar Absorptivity ◽  
Alizarin Yellow ◽  
Low Concentrations ◽  
Relative Standard ◽  
Seawater Samples ◽  
Almost All

The present study describes a simple and highly selective method for separation, preconcentration and spectrophotometric determination of extremely low concentrations of lead. It is based on flotation of a complex of Pb2+ ions and Alizarin yellow between aqueous and n-hexane interface at pH = 6. The proposed procedure is also applied for determination of lead in both tap water and prepared sea water samples. Beer's Law was obeyed over the concentration range of 3.86 × 10−8 To 8.20 × 10−7 molL−1 (8-170 ngmL−1) with an apparent molar absorptivity of 1.33 × 106 molL−1 cm−1 for a 100 mL aliquot of the water sample. The detection limit (n = 10) was 8.7 × 10−9 molL−1 (1.0 ngmL−1) and the Relative standard deviation (R.S.D), (n = 10) for 7.2 × 10−7 molL−1 (150 ngmL−1) of Pb (II) was 4.36%. A notable advantage of the method is that the determination of Pb (II) is free from the interference of almost all cations and ions found in the environment and waste water samples. The determination of Pb (II) in tap and synthetic seawater samples was also carried out by the present method. The results were satisfactorily comparable so that the applicability of the proposed method was confirmed to the real samples.

Β-Cyclodextrin-Cross-Linked Polymer Microcolumn Dynamic Preconcentration/analysis for Trace Cadium

2011 ◽  
Vol 284-286 ◽  
pp. 82-86
Author(s):  
Xia Shi Zhu ◽  
Ying Gu ◽  
Ting Ting Hou
Keyword(s):  
Standard Deviation ◽  
Detection Limit ◽  
Reference Material ◽  
Water Samples ◽  
Enhancement Factor ◽  
Optimum Conditions ◽  
Column Method ◽  
Relative Standard ◽  
Trace Cadmium

The adsorptive capability of β-Cyclodextrin-cross-linked polymer(β-CDCP) for cadmium was assessed in this work using column method. It was found that the complex (Cd(II)-5-Br-PADAP) could be quantitatively retained on the β-CDCP in the pH 8.5, eluted completely with 1.5 mol×L-1HCl. Under the optimum conditions, the linear range, detection limit (DL) and the relative standard deviation (R.S.D.) was 2.0-60.0 μg×L-1, 7.8 ng×L-1and 2.20% (n=3, c=20.0 μg×L-1) respectively. The separation of Cd(II) was achieved from water samples with an enhancement factor of 20. Moreover, the β-CDCP could be used repeatedly and offered better recovery. The method was validated using a certified reference material, and applied for the determination of trace cadmium in water samples.

An Automated Procedure for the Determination of Ammonia in Tobacco

1972 ◽  
Vol 6 (4) ◽  
Author(s):  
P.F. Collins ◽  
W.W. Lawrence ◽  
J.F. Williams
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Distillation Method ◽  
Relative Standard ◽  
Tobacco Sample ◽  
Automated Determination

AbstractA procedure for the automated determination of ammonia in tobacco has been developed. Ammonia is extracted from the ground tobacco sample with water and is determined with a Technicon Auto Analyser system which employs separation of the ammonia through volatilization followed by colourimetry using the phenate-hypochlorite reaction. The procedure has been applied to a variety of tobaccos containing from 0.02 to 0.5 % ammonia with an overall relative standard deviation of 2 %. The accuracy of the procedure as judged by recovery tests and by comparison to a manual distillation method is considered adequate

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 Indirect and Direct Determination of the Casein Content of Milk by Kjeldahl Nitrogen Analysis: Collaborative Study

1998 ◽  
Vol 81 (4) ◽  
pp. 763-774 ◽  
Author(s):  
Joanna M Lynch ◽  
David M Barbano ◽  
J Richard Fleming
Keyword(s):  
Standard Deviation ◽  
Nitrogen Content ◽  
Relative Standard Deviation ◽  
Collaborative Study ◽  
Direct Determination ◽  
Raw Milk ◽  
Method Performance ◽  
Relative Standard ◽  
Milk Casein

Abstract The classic method for determination of milk casein is based on precipitation of casein at pH 4.6. Precipitated milk casein is removed by filtration and the nitrogen content of either the precipitate (direct casein method) or filtrate (noncasein nitrogen; NCN) is determined by Kjeldahl analysis. For the indirect casein method, milk total nitrogen (TN; Method 991.20) is also determined and casein is calculated as TN minus NCN. Ten laboratories tested 9 pairs of blind duplicate raw milk materials with a casein range of 2.42- 3.05℅ by both the direct and indirect casein methods. Statistical performance expressed in protein equivalents (nitrogen ⨯ 6.38) with invalid and outlier data removed was as follows: NCN method (wt%), mean = 0.762, sr = 0.010, SR = 0.016, repeatability relative standard deviation (RSDr) = 1.287℅, reproducibility relative standard deviation (RSDR) = 2.146%; indirect casein method (wt℅), mean = 2.585, repeatability = 0.015, reproducibility = 0.022, RSDr = 0.560℅, RSDR = 0.841; direct casein method (wt℅), mean = 2.575, sr = 0.015, sR = 0.025, RSDr = 0.597℅, RSDR = 0.988℅. Method performance was acceptable and comparable to similar Kjeldahl methods for determining nitrogen content of milk (Methods 991.20, 991.21,991.22, 991.23). The direct casein, indirect casein, and noncasein nitrogen methods have been adopted by AOAC INTERNATIONAL.

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