Spectrophotometric Determination of Mercury in Water Samples After Preconcentration Using Dispersive Liquid–Liquid Microextraction

2012 ◽  
Vol 95 (1) ◽  
pp. 227-231 ◽  
Author(s):  
Valfredo Azevedo Lemos ◽  
Liz Oliveira dos Santos ◽  
Eldevan dos Santos Silva ◽  
Emanuel Vitor dos Santos Vieira
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Sea Water ◽  
Certified Reference Materials ◽  
Simple Method ◽  
Rich Phase ◽  
Subsequent Determination ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

Abstract A simple method for the determination of mercury in water samples after preconcentration using dispersive liquid–liquid microextraction is described. The procedure is based on the extraction of mercury in the form of a complex and its subsequent determination by spectrophotometry. The complex is formed between Hg(II) and 2-(2-benzothiazolylazo)-p-cresol. The detection at 650 nm is performed directly in the metal-rich phase, which is spread on a triacetylcellulose membrane. The method eliminates the need to use a cuvet or large quantities of samples and reagents. The parameters that influence the preconcentration were studied, and the analytical characteristics were determined. The enrichment factor and the consumptive index for this method were 64 and 0.16 mL, respectively. The LOD (3.3 μg/L) and LOQ (11.1 μg/L) were also determined. The accuracy of the method was tested by the determination of mercury in certified reference materials BCR 397 (Human Hair) and SRM 2781 (Domestic Sludge). The method was applied to the determination of mercury in samples of drinking water, sea water, and river water.

Evaluation of Mercury in Environmental Samples by a Supramolecular Solvent–Based Dispersive Liquid–Liquid Microextraction Method Before Analysis by a Cold Vapor Generation Technique

2017 ◽  
Vol 100 (3) ◽  
pp. 782-788 ◽  
Author(s):  
Jamshed Ali ◽  
Mustafa Tuzen ◽  
Tasneem G Kazi
Keyword(s):  
Certified Reference Materials ◽  
Experimental Conditions ◽  
Simple Method ◽  
Cold Vapor ◽  
Solvent Phase ◽  
Supramolecular Solvent ◽  
Thar Coalfield ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

Abstract Supramolecular solvent–based dispersive liquid–liquid microextraction was used as a preconcentration method for the determination of trace levels of Hg. This simple method accurately measured oxidized HgII content inclaystone and sandstone samples obtained from the Thar Coalfield in Pakistan. Cold vapor atomic absorption spectrometry was used as the detection technique because it is reliable and accurate. The HgII in acidic media forms a complexwith dithizone (DTz) in the presence of supramolecular solvent (tetrahydrofuran and 1-undecanol), forming reverse micelles. Formation of the Hg-DTz complex was achieved to increase the interactions with the supramolecular solvent phase at pH 2.5 under the optimized experimental conditions. After additionof the supramolecular solvent to the aqueous solution, the micelles were uniformly mixed using a vortex mixer. The cloudy solution was centrifuged, and the Hg-DTz complex was extracted into the supramolecular solvent phase. Under optimized experimental conditions, the LOD and enrichment factor were foundto be 5.61 ng/L and 77.8, respectively. Accuracy of the developed method was checked with Certified Reference Materials. The developed method was successfully applied for the determination of HgII in claystone and sandstone samples from the Block VII and Block VIII areas of the Thar Coalfield on the basis of depth.

scholarly journals Application of chemometrics for modeling and optimization of ultrasound-assisted dispersive liquid–liquid microextraction for the simultaneous determination of dyes

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Siroos Shojaei ◽  
Saeed Shojaei ◽  
Arezoo Nouri ◽  
Leila Baharinikoo
Keyword(s):  
Water Samples ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
World Population ◽  
Simple Method ◽  
Relative Standard ◽  
Ultrasound Assisted ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

AbstractAs the world population continues to grow, so does the pollution of water resources. It is, therefore, important to identify ways of reducing pollution as part of our effort to significantly increase the supply of clean and safer water. In this study, the efficiency of ultrasound-assisted dispersive liquid–liquid microextraction (UA-DLLME) as a fast, economical, and simple method for extraction malachite green (MG) and rhodamine B (RB) dyes from water samples is investigated. In optimal conditions, the linear dynamic range (LDR) for RB and MG is 7.5–1500 ng mL−1 and 12–1000 ng mL−1, respectively. The limit of detection (LOD) is 1.45 ng mL−1 and 2.73 ng mL−1, and limit of quantification (LOQ) is 4.83 ng mL−1 and 9.10 ng mL−1 for RB and MG, respectively. Extraction efficiency is obtained in the range of 95.53–99.60%. The relative standard deviations (RSD) in real water and wastewater samples are less than 3.5. The developed method is used successfully in the determination of RB and MG dyes from water samples and there are satisfactory results.

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