A NEW METHOD FOR THE MEASUREMENT OF COPPER(II)-COMPLEXING CAPACITY OF NATURAL WATERS BY BACK-EXTRACTION TECHNIQUE

1986 ◽  
Vol 15 (4) ◽  
pp. 605-608 ◽  
Author(s):  
Hideo Akaiwa ◽  
Hiroshi Kawamoto ◽  
Hiroshi Ogura
Keyword(s):  
Natural Waters ◽  
New Method ◽  
Extraction Technique ◽  
Back Extraction ◽  
Complexing Capacity

A dynamic gas extraction-assisted paper-based method for colorimetric determination of bromides

2020 ◽  
Vol 12 (4) ◽  
pp. 587-594 ◽  
Author(s):  
Marina O. Gorbunova ◽  
Maria S. Garshina ◽  
Margarita S. Kulyaginova ◽  
Vladimir V. Apyari ◽  
Aleksei A. Furletov ◽  
...  
Keyword(s):  
Natural Waters ◽  
New Method ◽  
Colorimetric Determination ◽  
Gas Extraction ◽  
Selective Determination

A new method for selective determination of bromides in natural waters, foodstuffs and pharmaceuticals has been developed.

Determination of the aluminium complexing capacity of fulvic acids and natural waters, with examples from five New Zealand rivers

1996 ◽  
Vol 47 (1) ◽  
pp. 11 ◽  
Author(s):  
DJ Hawke ◽  
KJ Powell ◽  
JE Gregor
Keyword(s):  
Reaction Time ◽  
Natural Waters ◽  
Fulvic Acids ◽  
Operational Definition ◽  
Experimental Conditions ◽  
River Waters ◽  
Complexation Capacity ◽  
Complexing Capacity ◽  
Definition Of

An FIA technique with 7 s reaction time was used to analyse free plus labile Al in fulvic acid (FA) solutions and natural waters at pH 4.7, without the need for separation procedures. Titrations of these solutions using incremental pH or total Al were used to determine pH binding curves or estimates of the 'kinetic' Al complexation capacity (Al-CCk) respectively. The operational definition of Al-CCk relates to the capacity of a humic substance or natural water to bind Al through a 7-s FIA reaction time under defined experimental conditions of chromophore (CAS) concentration, ionic strength, and pH. Both Al binding strength and complexation capacity were greater than the corresponding Cu-CC (ISE) values. The Al-CCk measurements at pH 4.7 were 710 μmol Al g-1 v. 590 μmol Cu g-1. Al-CCk results (pH 4.7) were higher for soil FA (710 μmol g-1) than for aquatic FA (390 μmol g-1). Al-CCk results (pH 4.7) for five unfiltered river waters from different catchments gave results in the range 6.5-9.8 μmol Al L-1. The differences between total (natural) Al in the samples and Al-CCk were between 2.7 μM and 8.6 μM. Filtration experiments identified fractionation patterns between total (natural) Al and the fraction of Al-CCk not utilized. The Al titration of alginate, another component of natural organic matter, is reported.

Determination of Free Metal Ion Concentrations Using Bioassays

1981 ◽  
Vol 38 (8) ◽  
pp. 999-1002 ◽  
Author(s):  
Uwe Borgmann
Keyword(s):  
Metal Toxicity ◽  
Metal Ion ◽  
Natural Waters ◽  
Complexing Agent ◽  
Aquatic Life ◽  
Ion Concentrations ◽  
Complexing Capacity ◽  
Before And After ◽  
Free Metal ◽  
Free Metal Ion

A procedure was developed by which free metal ion concentrations, toxic to aquatic life, can be calculated by comparing metal toxicity before and after addition of a complexing agent of known complexing capacity. Application of this method suggests that the growth of freshwater copepods is affected at free copper concentrations around 10−10 to 10−9 mol∙L−1. In natural waters, with unidentified ligands of unknown complexing ability, this procedure provides the only method currently available for estimating free metal concentrations at the low levels often causing sublethal toxicity to aquatic organisms.Key words: metal toxicity, complexation, free metal, copepods, copper

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