scholarly journals Solidified Floating Organic Drop Microextraction for the Detection of Trace Amount of Lead in Various Samples by Electrothermal Atomic Absorption Spectrometry

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Oya Aydın Urucu ◽  
Şeyda Dönmez ◽  
Ece Kök Yetimoğlu

A novel method was developed for determination of trace amounts of lead in water and food samples. Solidified floating organic drop microextraction was used to preconcentrate the lead ion. After the analyte was complexed with 1-(2-pyridylazo)-2-naphthol, undecanol and acetonitrile were added as extraction and dispersive solvent, respectively. Variables such as pH, volumes of extraction and dispersive solvents, and concentration of chelating agent were optimized. Under the optimum conditions, the detection limit of Pb (II) was determined as 0.042 µg L−1 with an enrichment factor of 300. The relative standard deviation is <10%. Accuracy of the developed procedure was evaluated by the analysis of certified reference material of human hair (NCS DC 73347) and wastewater (SPS-WW2) with satisfactory results. The developed procedure was then successfully applied to biscuit and water samples for detection of Pb (II) ions.

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Sabah Shiri ◽  
Tahere Khezeli ◽  
Shahram Lotfi ◽  
Sina Shiri

A novel, simple, and more sensitive spectrophotometric procedure has been developed for the determination of brilliant blue FCF in water and food samples by an aqueous two-phase system (ATPS). In this method, adequate amount of polyethylene glycol/ sodium carbonate (PEG-4000/Na2CO3) was added to aqueous solution for formation of a homogeneous solution. To the mixture solution, suitable amount ofNa2CO3was added, the mixture solution was shaken until the salt was dissolved, and then it was separated into two clear phases easily and rapidly. The target analyte in the water sample was extracted into the polyethylene glycol phase. After extraction, measuring the absorbance at 634 nm was done. The effects of different parameters such as polyethylene glycol (type and concentration), pH, salt (type and amount), centrifuge time, and temperature on the ATPS of dye was investigated and optimum conditions were established. Linear calibration curves were obtained in the range of 0.25–750 ng/mL for brilliant blue FCF under optimum conditions. Detection limit based on three times the standard deviation of the blank (3Sb) was 0.12 ng/mL. The relative standard deviation (RSD) for 400 ng/mL was 3.14%. The method was successfully applied to the determination of brilliant blue FCF in spiked samples with satisfactory results. The relative recovery was between 96.0 and 102.2%.


2013 ◽  
Vol 333-335 ◽  
pp. 1807-1810
Author(s):  
De Yi Zhang ◽  
Li Wen Zheng

In this paper, a novel method fog determination of chemiluminescence (CL) spectra utilizing LS55 luminescence spectrophotometer was proposed. By this means, the CL spectra generated from the oxidation of cephalosporins with potassium permanganate was investigated. The result indicated that acid potassium permanganate CL system has more then three emitting species, excited state Mn(Ⅱ), Mn(Ⅲ) and singlet oxygen all could be assigned as the possible emitting species of this CL system. Base on above investigation results, sodium cefoperazone in pharmaceutical samples was determined by a CL analysis process combining with flow-injection technique. The detection limits estimated by a conservative model (3σ) of cefoperazone was 0.1µg dm-3, and the maximum relative standard deviation (RSD) was not more than 0.8 % (n=11, ρ=20µg dm-3).


2005 ◽  
Vol 88 (4) ◽  
pp. 1242-1246 ◽  
Author(s):  
Marcos M Kaplan ◽  
Soledad Cerutti ◽  
José A Salonia ◽  
José A Gásquez ◽  
Luis D Martinez

Abstract A procedure for the determination of traces of total tellurium (Te) in garlic (Allium sativa) is described that combines hydride generation atomic absorption spectrometry with preconcentration of the analyte by coprecipitation. The samples, each spiked with lanthanum nitrate (20 mg/L), are introduced into an Amberlite XAD-4 resin and mixed with ammonium buffer (pH 9.1). Te is preconcentrated by coprecipitation with the generated lanthanum hydroxide precipitate. The precipitate is quantitatively collected in the resin, eluted with hydrochloric acid, and then transferred into the atomizer device. Considering a sample consumption of 25 mL, an enrichment factor of 10 was obtained. The detection limit (3σ) was 0.03 μg/L, and the precision (relative standard deviation) was 3.5% (n = 10) at the 10 μg/L level. The calibration graph using the preconcentration system for Te was linear with a correlation coefficient of 0.9993. Satisfactory results were obtained for the analysis of Te in garlic samples.


1974 ◽  
Vol 57 (2) ◽  
pp. 368-372 ◽  
Author(s):  
Milan Ihnat

Abstract A fluorometric method using 2,3-diaminonaphthalene for estimating selenium has been evaluated with regard to its applicability to food samples. Charring of the sample during digestion appeared to result in losses of native and added selenium from some samples, so a modified wet digestion procedure was introduced. Digestion first in nitric acid followed by a mixture of nitric-perchloric-sulfuric acids substantially reduced the incidence of sample charring for a variety of foods. The mean apparent recovery of selenium added as selenite or selenate at 100 and 500 ng levels to 0.1 and 1.0 g corn cereal, skim milk powder, and meat and 0.1 g fish was 101.0%; the actual recovery of the same levels of selenium from standard solutions was 96.6%. For a variety of samples containing 5—750 ng native or added selenium, the standard deviation as 4.7 + 1.95 X 10-2W ng, where W = ng selenium in the sample taken for analysis. The relative standard deviation (RSD) as a function of selenium weight (ng) was 50% (10), 6.7% (100), 4.3% (200), 3.1% (400), 2.7% (600), and 2.5% (800). The detection limit (weight of selenium at which RSD = 50%) was 10 ng at a mean blank level of 25 ng.


2000 ◽  
Vol 83 (5) ◽  
pp. 1204-1211 ◽  
Author(s):  
Lars Jorhem ◽  
G Afthan ◽  
G Cumont ◽  
H P Dypdahl ◽  
K Gadd ◽  
...  

Abstract A method for determination of lead, cadmium, zinc, copper, and iron in foods by atomic absorption spectrometry (AAS) after dry ashing at 450°C was collaboratively studied in 16 laboratories. The study was preceded by a practice round of familiarization samples and another round in which solutions were distributed and the metals were determined directly by AAS. The study included 5 different foods (liver paste, apple sauce, minced fish, wheat bran, and milk powder) and 2 simulated diets. A single analysis was carried out with each sample. Suitable sample combinations were used as split-level combinations for determination of the repeatability standard deviation. The reproducibility relative standard deviation for each of the elements ranged from 20 to 50% for lead concentrations of 0.040–0.25 mg/kg, from 12 to 352% for cadmium concentrations of 0.001–0.51 mg/kg, from 4 to 8% for zinc concentrations of 0.7–38 mg/kg, from 7 to 45% for copper concentrations of 0.51–45 mg /kg, and from 11 to 14% for iron concentrations of 4–216 mg/kg.


2000 ◽  
Vol 83 (6) ◽  
pp. 1423-1428 ◽  
Author(s):  
Kaare Julshamn ◽  
Arngriimur Thorlacius ◽  
Per Lea ◽  
Kjetil Barland ◽  
Kari Eidem ◽  
...  

Abstract Eight laboratories participated in an interlaboratory method performance (collaborative) study of a method for the determination of arsenic in foodstuffs of marine origin by electrothermal atomic absorption spectrometry after wet digestion using a microwave oven technique. The study was preceded by a practice round of familiarization samples. The method was tested on 8 materials (cod roe, krill, blue mussel, saithe, scampi, cod fillet, shrimp, and cod extract) ranging in As content from 2 to 75 mg/kg. The materials were sent to participants in the study as blind duplicates, and the participants were asked to perform single determinations on each sample. Repeatability relative standard deviations (RSDr) for As ranged from 6.8 to 17.4%. Reproducibility relative standard deviations (RSDR) ranged from 7.6 to 24%. The highest RSDR value was found for the sample with the highest concentration of As.


2011 ◽  
Vol 306-307 ◽  
pp. 688-691 ◽  
Author(s):  
Hai Yan Zhuang ◽  
Hui Zhi Li ◽  
Yang Xue

A new ion-imprinted polymer (IIP) material was synthesized by copolymerization of 4-vinylpyridine(VP) as monomer, ethylene glycol dimethacrylate(EGDMA) as crosslinking agent and 2,2΄-azobisisobutyronitrile(AIBN) as initiator in the presence of Pb–1,5-diphenylcarbazone(Pb-DHCB) complex. Blank non-imprinted polymer (NIP) were prepared under identical conditions without the use of lead imprint ion. The synthesized polymers were characterized by IR spectroscopy and elemental analyzer techniques. Of the several polymers synthesized, only the imprinted polymer formed with binary complex of Pb2+–DHCB showed quantitative enrichment of lead ion from aqueous solution. The relative standard deviation of the five replicate determinations of Pb (II) was3.26%. The detection limit for 150 mL of sample was 1.6 µg L-1 using flame atomic absorption spectrometry. The developed method was successfully applied to the determination of trace lead in environmental samples with satisfactory results.


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