scholarly journals Preconcentration method for trace metals in natural waters using 4-morpholine dithiocarbamate

2002 ◽  
Vol 67 (12) ◽  
pp. 879-885 ◽  
Author(s):  
Zoran Todorovic ◽  
Predrag Polic ◽  
Tibor Sabo ◽  
Milorad Cakic
Keyword(s):  
Trace Metals ◽  
Organic Solvent ◽  
Water Samples ◽  
Natural Waters ◽  
Optimum Conditions ◽  
Metal Analysis ◽  
Preconcentration Method

The optimum conditions were found for the preconcentration of trace metals in natural waters and model samples with standard metals concentrations by using 4-morpholine dithiocarbamate. The formed complexes were extracted with chloroform. Different methods for recovering the metals from the organic solvent were studied and compared before AAS metal analysis. The developed preconcentration method was successfully applied to the determination of trace metals concentrations in water samples from the "Barje" lake (Leskovac, Yugoslavia).

scholarly journals Vortex-assisted liquid–liquid microextraction combined with spectrophotometry for the determination of trace nitrite in water samples

2017 ◽  
Vol 17 (5) ◽  
pp. 1225-1231 ◽  
Author(s):  
Yang Jiao ◽  
Jianping Yu ◽  
Yaling Yang
Keyword(s):  
Organic Solvent ◽  
Water Samples ◽  
Limit Of Detection ◽  
Environmental Water ◽  
Cationic Dye ◽  
Optimum Conditions ◽  
Relative Standard ◽  
Optimized Conditions ◽  
Liquid Microextraction

A vortex-assisted liquid–liquid microextraction (VALLME) method using isooctanol as extractant followed by spectrophotometry was developed for the extraction and determination of trace nitrite in water samples. The method is based on selective ion-pairing complex (I3− MG+) formation of triiodideanion I3− with cationic dye malachite green (MG) at pH 3.0, and its subsequent extraction in an organic solvent. The extracted organic solvent-rich phase is diluted with methanol, and its absorbance is measured against an analyte blank at 630 nm. The variables affecting VALLME efficiency were investigated, and a set of optimized conditions was obtained. Under the optimum conditions, the linear range of nitrite was from 1.0 to 100 ng mL−1. The relative standard deviations (n = 10) were 2.1–3.9% and the limit of detection was 0.5 ng mL−1 and was successfully applied to the determination of nitrite in environmental water.

Development of a preconcentration method for indomethacin in natural waters using dispersive liquid–liquid microextraction based on solidification of floating organic drop technique

2018 ◽  
Vol 53 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Nesrin Topaç ◽  
Cennet Karadaş ◽  
Derya Kara
Keyword(s):  
Water Samples ◽  
Natural Waters ◽  
Limit Of Detection ◽  
Tap Water ◽  
Chloride Concentration ◽  
Extraction Solvent ◽  
Dispersive Liquid Liquid Microextraction ◽  
Preconcentration Method ◽  
Liquid Microextraction

Abstract A new dispersive liquid–liquid microextraction method based on the solidification of a floating organic drop was developed for the preconcentration of indomethacin in natural waters followed by ultraviolet-visible (UV-Vis) spectrophotometric detection. 1-undecanol and ethanol were used as the extraction solvent and the disperser solvent, respectively. An investigation of the main experimental parameters that may affect the extraction efficiency, such as sample pH, volume of extraction and disperser solvents, sodium chloride concentration and centrifugation time was undertaken. The effect of interfering ions on the recovery of indomethacin was also examined. Under optimal conditions without any preconcentration, the limit of detection was 17.9 μg/L calculated from LOD = 3 Sb/m and was also calculated as 74.9 μg/L from the regression values of the calibration line using 3.19 Se/m. The proposed preconcentration method was successfully applied to determination of indomethacin in spiked tap water and river water samples. The recovery values for spikes added to water samples were between 94.5 and 103.0%.

A batch method for the determination of ion-exchangeable trace metals in natural waters

1977 ◽  
Vol 28 (3) ◽  
pp. 397 ◽  
Author(s):  
BT Hart ◽  
HR Davies
Keyword(s):  
Trace Metals ◽  
Natural Water ◽  
Water Samples ◽  
Natural Waters ◽  
Field Studies ◽  
Metal Species ◽  
Batch Method ◽  
Chelex 100 ◽  
Natural Water Samples

A batch method for the determination of ion-exchangeable trace metals in natural waters is reported. The technique employs the resin Chelex 100 and has been tested for Cd, Cu, Pb, Zn and Fe using both synthetic and natural water samples. Quantitative recovery of ionic spikes was achieved and uptake was found to occur rapidly, being virtually completed within 1 h. Evidence is provided for the presence in the natural water samples of stable bound trace metal species. This batch method should prove particularly useful for field studies of the physicochemical forms of trace metals in aquatic environments.

scholarly journals Investigation of the extraction equilibrium of ion-association complexes of molybdenum (VI) with some polyphenols and thiazolyl blue. extraction-spectrophotometric determination of molybdenum

2005 ◽  
Vol 3 (4) ◽  
pp. 747-755 ◽  
Author(s):  
Atanas Dimitrov ◽  
Vania Lekova ◽  
Kiril Gavazov ◽  
Boyan Boyanov
Keyword(s):  
Organic Solvent ◽  
Aqueous Medium ◽  
Spectrophotometric Method ◽  
Ion Association ◽  
Extraction Process ◽  
Association Constants ◽  
Optimum Conditions ◽  
Extraction Equilibrium ◽  
Simple Extraction

AbstractThe extraction process of ternary ion-association complexes of molybdenum (VI) with some polyphenols (4-nitrocatechol, 2,3-dihydroxy naphthalene) and thiazolyl blue has been investigated by using an extraction-spectrophotometric method. The optimum conditions for their quantitative preparation in aqueous medium and subsequent extraction into an organic solvent have been found. The extraction, distribution and association constants, and the recovery factors have been calculated. The composition of the complexes has been determined. A precise, sensitive and simple extraction-spectrophotometric method for determination of molybdenum in products from ferrous metallurgy has been developed.

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