FIA-coupled spectrophotometric method for determination of Cr (VI) traces in natural waters: application of in-line dissolution of 1,5-diphenylcarbazide after heat treatment and activated alumina as adsorbent for preconcentration

2018 ◽  
Vol 190 (10) ◽  
Author(s):  
Diogenes Meneses ◽  
José Guimarães F. Júnior ◽  
Paulo Cesar Costa de Oliveira
Keyword(s):  
Heat Treatment ◽  
Spectrophotometric Method ◽  
Natural Waters ◽  
Activated Alumina

Improved ultraviolet spectrophotometric method for determination of nitrate in natural waters

2002 ◽  
Vol 2 (2) ◽  
pp. 213-221 ◽  
Author(s):  
N. Kishimoto ◽  
I. Somiya ◽  
R. Taniyama
Keyword(s):  
Water Quality ◽  
Spectrophotometric Method ◽  
Standard Error ◽  
Coefficient Of Variation ◽  
Natural Waters ◽  
Uv Light ◽  
Rapid Determination ◽  
The Other ◽  
Extreme Conditions

An improved UV spectrophotometric method for determination of nitrate in natural waters was proposed and the determination accuracy of the method was discussed in this study. As a result of estimation of the proposed method, adoption of 215 and 220 nm for detection of nitrate and interfering substances resulted in decreasing standard error to about a half of that of a conventional spectrophotometric method. One of the reasons was thought that the coefficient of variation of relative absorbance of interfering substances (rs) at 215 nm was smaller and more stable than that at 275 nm, which was used in the conventional method. The other reason inferred was that most of the interfering substances absorbed UV light at wavelengths of 215 and 220 nm. Although rs has to be renewed when targeted water quality is under extreme conditions, the procedure of the proposed method is very simple, namely only measuring two UV absorbances of a filtrated sample, and more accurate than the conventional spectrophotometric method. Consequently, the proposed method is available for rapid determination of nitrate in natural waters.

scholarly journals Direct and simultaneous spectrophotometric determination of Ni (II) and Co (II) using diethanoldithiocarbamate as complexing agent

2009 ◽  
Vol 34 (2) ◽  
pp. 7-13 ◽  
Author(s):  
P. A. Antunes ◽  
G. Bannach ◽  
G. O. Chierice ◽  
E. T. G. Cavalheiro
Keyword(s):  
Simultaneous Determination ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Natural Waters ◽  
Maximum Absorption ◽  
Complexing Agent ◽  
Mixing Ratios ◽  
Ligand Ratio ◽  
Metal Ligand

A direct spectrophotometric method for simultaneous determination of Co(II) and Ni(II), with diethanoldithiocarbamate (DEDC) as complexing agent, is proposed using the maximum absorption at 360 and 638 nm (Co(II)/DEDC) and 390 nm (Ni/DEDC). Adjusting the best metal/ligand ratio, supporting eletrolite, pH, and time of analysis, linear analytical curves from 1.0 10-6-4.0 10-4 for Co(II) in the presence of Ni 1.0 10-6-1.0 10-4 mol L-1 were observed. No further treatment or calculation processes have been necessary. Recoveries in different mixing ratios were of 99%. Interference of Fe(III), Cu(II), Zn(II) and Cd(II), and anions as NO3-, Cl-, ClO4-, citrate and phosphate has been evaluated. The method was applied to natural waters spiked with the cations.

A NEW SIMULTANEOUS SPECTROPHOTOMETRIC METHOD FOR DETERMINATION OF IRON(II) AND IRON(III) IN NATURAL WATERS

2001 ◽  
Vol 34 (3) ◽  
pp. 289-300 ◽  
Author(s):  
Madalena C. da Cunha Areias ◽  
Lúcia Helena S. Ávila-Terra ◽  
Ivanise Gaubeur ◽  
Maria Encarnación V. Suárez-Iha
Keyword(s):  
Spectrophotometric Method ◽  
Natural Waters

scholarly journals Direct and simultaneous spectrophotometric determination of Ni (II) and Co (II) using diethanoldithiocarbamate as complexing agent

2018 ◽  
Vol 34 (2) ◽  
pp. 07
Author(s):  
Patrícia Alexandra Antunes ◽  
Gilbert Bannach ◽  
Gilberto Orivaldo Chierice ◽  
Éder Tadeu Gomes Cavalheiro
Keyword(s):  
Simultaneous Determination ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Natural Waters ◽  
Maximum Absorption ◽  
Complexing Agent ◽  
Mixing Ratios ◽  
Ligand Ratio ◽  
Metal Ligand

A direct spectrophotometric method for simultaneous determination of Co(II) and Ni(II), with diethanoldithiocarbamate (DEDC) as complexing agent, is proposed using the maximum absorption at 360 and 638 nm (Co(II)/DEDC) and 390 nm (Ni/DEDC). Adjusting the best metal/ligand ratio, supporting eletrolite, pH, and time of analysis, linear analytical curves from 1.0 10-6-4.0 10-4 for Co(II) in the presence of Ni 1.0 10-6-1.0 10-4 mol L-1 were observed. No further treatment or calculation processes have been necessary. Recoveries in different mixing ratios were of 99%. Interference of Fe(III), Cu(II), Zn(II) and Cd(II), and anions as NO3-, Cl-, ClO4-, citrate and phosphate has been evaluated. The method was applied to natural waters spiked with the cations.

A new extraction–spectrophotometric method for the determination of phosphate

1978 ◽  
Vol 56 (13) ◽  
pp. 1729-1738 ◽  
Author(s):  
Kunnath S. Subramanian ◽  
Alfio Corsini
Keyword(s):  
Spectrophotometric Method ◽  
Natural Waters ◽  
Amyl Alcohol ◽  
Tungstophosphoric Acid ◽  
Molar Ratio ◽  
Molybdenum Blue ◽  
Phosphorus Containing ◽  
Precision And Accuracy ◽  
Ph Range

A new extraction–spectrophotometric method has been developed for the determination of trace amounts of phosphorus as orthophosphate. The method is based on the chemistry of 12-tungstophosphoric acid, H3PW12O40 (TPA). In the procedure, orthophosphate is converted quantitatively to TPA in aqueous solution at a tungstate–phosphate molar ratio ≥24, in the pH range 1.2 to 1.9 and in the temperature range 60 to 100 °C. The TPA is subsequently extracted into n-amyl alcohol and its absorbance measured at 267 nm. Beer's law is followed up to at least 25 µg/ml P. The method is less prone to solution conditions and species interference (especially As(V) and Si(IV)) than the widely used molybdenum-blue methods and is competitive in terms of sensitivity, precision, and accuracy. The TPA method was applied successfully to the determination of phosphate in a variety of phosphorus-containing specimens including natural waters, ores, and alloys.Based on potentiometric and spectrophotometric studies, a scheme which accounts for the observed heptaproticity of TPA is proposed.

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