scholarly journals Homogeneous Liquid-Liquid Extraction Method for Selective Separation and Preconcentration of Trace Amounts of Palladium

2009 ◽  
Vol 6 (4) ◽  
pp. 1077-1084 ◽  
Author(s):  
Mohammad Reza Jamali ◽  
Yaghoub Assadi ◽  
Reyhaneh Rahnama Kozani ◽  
Farzaneh Shemirani
Keyword(s):  
Extraction Method ◽  
Limit Of Detection ◽  
Liquid Extraction ◽  
Selective Separation ◽  
Complexing Agent ◽  
Homogeneous Liquid ◽  
Liquid Liquid Extraction ◽  
Relative Standard ◽  
Separation And Preconcentration ◽  
Ternary Component System

A simple and effective homogeneous liquid-liquid extraction method for selective separation, preconcentration and spectrophotometric determination of palladium(II) ion was developed by using a ternary component system (water / tetrabutylammonium ion (TBA+) / chloroform). The phase separation phenomenon occurred by an ion–pair formation of TBA+and perchlorate ion. Thio-Michler’s ketone (TMK), 4, 4ˊ-bis (dimethylamino) thiobenzophenone, was used as a complexing agent. After optimization of complexation and extraction conditions ([TMK]=5.0x10-2mol L-1, [TBA+] = 2.0×10-2mol L-1, [CHCl3] = 60.0 µL, [ClO4-] = 2.5×10-2mol L-1and pH= 3.0), a preconcentration factor 10 was obtained for 10 mL of sample. The analytical curve was linear in the range of 2-100 ng mL-1and the limit of detection was 0.4 ng mL-1. The relative standard deviation was 3.2% (n=10). Accuracy and application of the method was estimated by using test samples of natural and synthetic water spiked with different amounts of palladium(II) ion. The method is very simple and inexpensive.

scholarly journals POSSIBILITY OF THE SPECTROPHOTOMETRIC DETERMINATION OF EUROPIUM BY MEANS OF ARSENAZO III

2013 ◽  
Vol 12 (2) ◽  
pp. 93-99 ◽  
Author(s):  
Jozef Uhrovčík ◽  
Monika Gyeváthová ◽  
Juraj Lesný
Keyword(s):  
Limit Of Detection ◽  
Molar Absorptivity ◽  
Model Solution ◽  
Arsenazo Iii ◽  
Complexing Agent ◽  
Acceptable Range ◽  
Relative Standard ◽  
Separation And Preconcentration ◽  
Interfering Ions

Abstract The concentration of Eu(III) cations in model aqueous solutions can be quantified by means of Arsenazo III reagent. Absorbance of the solution was measured at the wavelength λmax = 655 nm. Molar absorptivity reached the value ε655 = 5.5±0.2 · 104 cm-1 mol-1 · dm3. Beer's law was obeyed in the range from 0 to 2 mg · dm-3 Eu(III). The value of limit of detection was established by application of 3σ approach and reached the value of 20.9 μg · dm-3. Repeatability of analysis expressed by relative standard deviation does not exceed the value of ± 8% and apparent recovery lay in acceptable range from 91 to 106 %. Stoichiometry between Eu(III) and Arsenazo III in media of relevant solution was 1:1. The absorbance of the solutions within the linear range of the proposed method maintained a constant value for 60 minutes. Described procedure can be utilized to determination of Eu(III) concentration in real samples, but it is necessary eliminate interfering ions. Cations like La(III), Sm(III), Th(IV), U(VI) and complexing agent EDTA cause significant error at the determination of Eu(III) in model solution. Presented spectrophotometric method could be applied for the determination of europium in the minerals and water samples, however after a suitable separation and preconcentration of target analyte.

Liquid–liquid extraction and cloud point extraction for spectrophotometric determination of vanadium using 4-(2-pyridylazo)resorcinol

2015 ◽  
Vol 69 (4) ◽  
Author(s):  
Teodora S. Stefanova ◽  
Kiril K. Simitchiev ◽  
Kiril B. Gavazov
Keyword(s):  
Cloud Point ◽  
Spectrophotometric Determination ◽  
Cloud Point Extraction ◽  
Limit Of Detection ◽  
Molar Absorptivity ◽  
Liquid Extraction ◽  
Optimal Conditions ◽  
Liquid Liquid Extraction ◽  
Relative Standard

AbstractLiquid-liquid extraction (LLE) and cloud point extraction (CPE) of vanadium(V) ternary complexes with 4-(2-pyridylazo)resorcinol (PAR) and 2,3,5-triphenyl-2H-tetrazolum chloride (TTC) were investigated. The optimal conditions for vanadium extraction and spectrophotometric determination were identified. The composition (V : PAR : TTC) of the extracted species was 1 : 2 : 3 (optimal conditions; LLE), 2 : 2 : 2 (low reagents concentrations; LLE), 1 : 1 : 1 (short heating time; CPE), and 1 : 1 : 1 + 1 : 1 : 0 (optimal extraction conditions; CPE). LLE, performed in the presence of 1,2-diaminocyclohexane-N,N,N’,N’-tetraacetic acid and NH4F as masking agents, afforded the sensitive, selective, precise, and inexpensive spectrophotometric determination of vanadium. The absorption maximum, molar absorptivity, limit of detection, and linear working range were 559 nm, 1.95 × 105 dm3 mol−1 cm−1, 0.7 ng cm−3, and 2.2-510 ng cm−3, respectively. The procedure thus developed was applied to the analysis of drinking waters and steels. The relative standard deviations for V(V) determination were below 9.4 % (4-6 × 10−7 mass %; water samples) and 2.12 % (1-3 mass %; steel samples).

scholarly journals New Sample Preparation Method for Honey Volatiles Fingerprinting Based on Dehydration Homogeneous Liquid–Liquid Extraction (DHLLE)

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1769 ◽  
Author(s):  
Piotr Kuś ◽  
Igor Jerković
Keyword(s):  
Sample Preparation ◽  
Preparation Method ◽  
Solvent Polarity ◽  
Liquid Extraction ◽  
Sample Preparation Method ◽  
Preparation Methods ◽  
Homogeneous Liquid ◽  
Liquid Liquid Extraction ◽  
Relative Standard ◽  
Honey Solution

Qualitative chemical fingerprinting of the honey volatiles by gas chromatography and mass spectrometry (GC-MS) has been an efficient authentication tool that allowed for the classification of the honey botanical origin (strongly related to its medicinal and market value). However, the usage of current sample preparation methods is limited by selectivity of the volatiles extraction from the honey matrix and requires significant solvent volume. Therefore, a new sample preparation method based on dehydrating homogeneous liquid–liquid extraction (DHLLE) involving reduced solvent usage was developed for screening volatiles and semi-volatiles from the honey. The effective extraction was achieved by implementing a miscible liquid extraction system (aqueous honey solution/isopropanol) followed by separation through dehydration with MgSO4 and purification by a solvent polarity change and washing. The method was evaluated by estimating accuracy and precision. The DHLLE method showed satisfactory recoveries (75.2 to 93.5%) for typical honey volatiles: linalool, borneol, terpinen-4-ol, α-terpineol, p-anisaldehyde, eugenol, and vanillin. It also showed superior repeatability with percent relative standard deviation (RSD%) 0.8–8.9%. For benzyl alcohol, methyl syringate, and caffeine, the recoveries were 54.3 to 63.9% and 67.3 to 77.7% at lower and higher spiking levels, respectively. Applied to unifloral apple honey, the DHLLE method allowed for the identification of 40 compounds including terpenes, hydrocarbons, phenylpropanoids, and other benzene derivatives, which makes it suitable for fingerprinting and chemical marker screening. The obtained results were comparable or better than those obtained with ultrasonic extraction with dichloromethane.

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