scholarly journals Film Carbon Veil-Based Electrode Modified with Triton X-100 for Nitrite Determination

Chemosensors ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 78
Author(s):  
Natalia Yu. Stozhko ◽  
Maria A. Bukharinova ◽  
Ekaterina I. Khamzina ◽  
Aleksey V. Tarasov ◽  
Sergey V. Sokolkov
Keyword(s):  
High Selectivity ◽  
Limit Of Detection ◽  
Ionic Surfactant ◽  
Optimal Conditions ◽  
Nitrite Determination ◽  
Real Samples ◽  
Relative Standard ◽  
Triton X ◽  
Higher Sensitivity ◽  
Scanning Electron

A film carbon veil-based electrode (FCVE) modified with non-ionic surfactant Triton X-100 (TrX100) has been developed for nitrite determination. A new simple and producible technique of hot lamination (heat sealing) has been used for the FCVE manufacturing. The paper presents the findings of investigating the FCVE and the TrX100/FCVE by using voltammetry, chronoamperometry, and scanning electron microscopy. Modification of the electrode with TrX100 improves the hydrophilic property of its surface, which results in a larger electrode active area and higher sensitivity. Optimal conditions for nitrite determination with the use of the TrX100/FCVE have been identified. The linear range (LR) and the limit of detection (LOD) are 0.1–100 μM and 0.01 μM, respectively. The relative standard deviation (RSD) does not exceed 2.3%. High selectivity of the sensor ensures its successful application for the analysis of real samples (sausage products and natural water). The obtained results accord well with the results of the standard spectrophotometric method.

scholarly journals A Simple Pre-concentration Method for the Determination of Nickel(II) in Urine Samples Using UV-Vis Spectrophotometry and Flame Atomic Absorption Spectrometry Techniques

2019 ◽  
Vol 19 (3) ◽  
pp. 638 ◽  
Author(s):  
Ahmed Fadhil Khudhair ◽  
Mouyed Khudhair Hassan ◽  
Hasan F. Alesary ◽  
Ahmed S. Abbas
Keyword(s):  
Limit Of Detection ◽  
Ph Effect ◽  
Absorption Spectrometry ◽  
Bath Temperature ◽  
Urine Samples ◽  
Ionic Surfactant ◽  
Concentration Method ◽  
Flame Atomic Absorption ◽  
Relative Standard ◽  
Triton X

The cloud point technique was effectively utilized for extraction and pre-concentration of nickel(II) in urine samples before measurement by UV-Vis spectrophotometer and AAS techniques. The metal response to a para-aminophenol (PAP) reagent in a non-ionic surfactant Triton X-114 medium was to form the Ni-PAP complex. The adopted concentration for PAP, concentration of Triton X-114, pH effect and water bath temperature, incubation time, salt effect, and interference effects were all optimized. The calibration curve was linear over the range of (0.0625–1.25) mg L–1 with a correlation coefficient r2 of 0.9682 for the UV-Vis spectrophotometer at a λmax of 629 nm. The limit of detection was 0.005 mg/L. The relative standard deviation for six replicates was 1.07%. This method was applied successfully to determine copper (II) concentrations in 44 urine samples of occupational worker samples as determined by UV-Vis spectrophotometry and FAAS techniques.

scholarly journals Development of a Cloud-Point Extraction Method for Cobalt Determination in Natural Water Samples

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Mohammad Reza Jamali ◽  
Mohammad Gholinezhad ◽  
Saiedeh Balarostaghi ◽  
Reyhaneh Rahnama ◽  
Seyed Hojjat Allah Rahimi
Keyword(s):  
Cloud Point ◽  
Water Samples ◽  
Cloud Point Extraction ◽  
Limit Of Detection ◽  
Cobalt Content ◽  
Cobalt Ions ◽  
Flame Atomic Absorption ◽  
Relative Standard ◽  
Separation And Preconcentration ◽  
Triton X

A new, simple, and versatile cloud-point extraction (CPE) methodology has been developed for the separation and preconcentration of cobalt. The cobalt ions in the initial aqueous solution were complexed with 4-Benzylpiperidinedithiocarbamate, and Triton X-114 was added as surfactant. Dilution of the surfactant-rich phase with acidified ethanol was performed after phase separation, and the cobalt content was measured by flame atomic absorption spectrometry. The main factors affecting CPE procedure, such as pH, concentration of ligand, amount of Triton X-114, equilibrium temperature, and incubation time were investigated and optimized. Under the optimal conditions, the limit of detection (LOD) for cobalt was 0.5 μg L-1, with sensitivity enhancement factor (EF) of 67. Calibration curve was linear in the range of 2–150 μg L-1, and relative standard deviation was 3.2% (c=100 μg L-1;n=10). The proposed method was applied to the determination of trace cobalt in real water samples with satisfactory analytical results.

Electrocatalytic redox behavior of graphene films towards acebutolol hydrochloride determination in real samples

2016 ◽  
Vol 40 (4) ◽  
pp. 3763-3772 ◽  
Author(s):  
Atmanand M. Bagoji ◽  
Sharanappa T. Nandibewoor
Keyword(s):  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Limit Of Detection ◽  
Graphene Film ◽  
Carbon Electrode ◽  
Redox Behavior ◽  
Optimal Conditions ◽  
Modified Glassy Carbon Electrode ◽  
Real Samples ◽  
Graphene Films

Under optimal conditions, a graphene film modified glassy carbon electrode exhibited a longer linearity range from 3.36 to 57.12 ng mL−1 of acebutolol with a limit of detection of 0.131 ng mL−1.

scholarly journals Improvement of a 'SSQuEE' Method for Recovery and Preconcentration of Pesticides from Environmental Samples

2021 ◽  
Vol 33 (10) ◽  
pp. 2472-2476
Author(s):  
Rajib Joarder
Keyword(s):  
Cloud Point ◽  
High Performance ◽  
Limit Of Detection ◽  
Ionic Surfactant ◽  
Analytical Technique ◽  
Liquid Chromatography Separation ◽  
Cloud Point Temperature ◽  
Triton X ◽  
Optimum Extraction

A simple, sensitive, quick, easy and efficient (SSQuEE) analytical technique based on cloud point extraction (CPE) has been developed for the determination of different pesticides present in soil and water with high performance liquid chromatography separation and ultraviolet detection. The environmentally friendliness surfactant like Triton X -100, compared to Tween series of non-ionic surfactant can effectively extract imidacloprid (insecticide), flusilazole (fungicide) and atrazine (herbicide) at cloud point temperature at 67 ºC, 82 ºC and 62 ºC, respectively. To reach the optimum extraction efficiency, different experimental parameters like surfactant concentration, salt type and its concentration, equilibrium time and temperature, pH were observed. At the optimum conditions, linear regression coefficient of the standard curves was greater than 0.9924. The limit of detection of imidacloprid, flusilazole and atrazine were 0.10 μg L-1, 0.24 μg L-1, 0.15 μg L-1 and recovery percent are 99.71 %, 88.1% and 89.74%, respectively.

scholarly journals Micelle-Mediated Extraction Prior to LC-UV for Preconcentration and Determination of Trace Amounts of Bisphenol A in Environmental Samples

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Naghi Saadatjou ◽  
Shahab Shariati ◽  
Mostafa Golshekan
Keyword(s):  
Bisphenol A ◽  
High Performance ◽  
Limit Of Detection ◽  
Aqueous Samples ◽  
Limit Of Quantification ◽  
Rich Phase ◽  
Factors Affecting ◽  
Relative Standard ◽  
Triton X

A simple and high sensitive preconcentration method based on micelle-mediated extraction followed by high performance liquid chromatography (LC-UV) was developed for preconcentration and determination of trace amounts of bisphenol A (BPA) in aqueous samples. The BPA was quantitatively extracted from aqueous samples in the presence of Triton X-114 as a nonionic surfactant and preconcentrated into the small volume (about 30 μL) of the surfactant-rich phase. Taguchi method, an orthogonal array design (OA16 (45)), was utilized to optimize the various factors affecting the micellar extraction of BPA. The maximum extraction efficiency of BPA was obtained at pH 3, 0.2% (w/v) Triton X-114, and 0.25 mol L−1 sodium acetate. For the preconcentration, the solutions were incubated in a thermostatic water bath at 50°C for 7 min. After centrifuge and separation of aqueous phase, the surfactant-rich phase was diluted with 100 μL acetone and injected in the chromatographic system. Under the optimum conditions, preconcentration factor of 34.9 was achieved for extraction from 10 mL of sample solution and the relative standard deviation (RSD%) of the method was lower than 6.6%. The calibration curve was linear in the range of 0.5–150 μg L−1 with reasonable linearity (r2>0.9987). The limit of detection (LOD) based on S/N = 3 was 0.13 μg L−1 for 10 mL sample volumes. The limit of quantification (LOQ) based on S/N = 10 was 0.43 μg L−1 for 10 mL sample volumes. Finally, the applicability of the proposed method was evaluated by the extraction and determination of BPA in the real samples, and satisfactory results were obtained.

A Novel Multifunctional Near-Infrared Absorbing Dye for Hg2+ Recognition

2013 ◽  
Vol 320 ◽  
pp. 460-464
Author(s):  
Lei Hu ◽  
Ya Fei Zhang ◽  
Fang Kuo Wang ◽  
Zheng Quan Yan
Keyword(s):  
Standard Deviation ◽  
Aqueous Medium ◽  
Correlation Coefficient ◽  
Relative Standard Deviation ◽  
Near Infrared ◽  
High Selectivity ◽  
Limit Of Detection ◽  
Colorimetric Sensor ◽  
Uv Absorbance ◽  
Relative Standard

A novel near-infrared absorbing colorimetric sensor with multifunctional groups, bis-dibenzo-18-crown-6 squaraine (BCSQ), has been identified and applied for accurate Hg2+analysis based on the decrement of its UV absorbance (A) in the aqueous medium. The proposed method was successfully applied to analyse synthetic Hg2+samples and natural Hg2+samples. The results show that the linear range of Hg2+detection in aqueous medium is 7.5~150×108mol·L1with a correlation coefficient (R) of 0.9983 and a limit of detection (3σ, n=20) of 5.6 ×109mol·L1. The relative standard deviation (R.S.D.) for Hg2+detection was lower than 2.4% (n=5). The proposed method possesses the advantages of simplicity, rapidity, high selectivity and sensitivity.

scholarly journals Solvolysis kinetic study and direct spectrofluorimetric analysis of the fungicide benomyl in natural waters

2014 ◽  
Vol 33 (2) ◽  
pp. 237 ◽  
Author(s):  
Diène Diègane Thiare ◽  
Abdourakhmane Khonté ◽  
Diegane Sarr ◽  
Cheikh Diop ◽  
Mame Diabou Gaye-Seye ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Natural Waters ◽  
Limit Of Detection ◽  
Sodium Dodecyl ◽  
Fluorescence Signal ◽  
Aqueous Solvent ◽  
Spectrofluorimetric Method ◽  
Relative Standard ◽  
Triton X

<p>A direct spectrofluorimetric method for the quantitative analysis of benomyl in natural waters is described. Benomyl is an instable, fluorescent fungicide that mainly decomposes into carbendazim and n-butyl-isocyanate in organic and aqueous solutions. The kinetics of benomyl solvolysis reactions were investigated in organic solvents (methanol and acetonitrile) and in aqueous solvent systems, including β–cyclodextrin (β-CD), sodium dodecyl sulfate (SDS), dodecyltrimethylammonium chloride (DTAC), cetyltrimethylammonium chloride (CTAC), cetyltrimethylammonium hydroxide (CTAOH), Brij-700, Triton X-100 and water, at different pH and/or NaOH concentrations. The benomyl fluorescence signal was found to be quasi-completely stable in 10<sup>-2</sup> M NaOH aqueous solution, various alkaline (10<sup>-2</sup> M NaOH) organized media, β-CD neutral solution and Triton X-100 aqueous solutions of different pH. Based on these results, a direct spectrofluorimetric analytical method was developed for the determination of benomyl in 10<sup>-2</sup> M NaOH aqueous solution and Triton X-100 solutions (pH7 and 10<sup>-2</sup> M NaOH), with wide linear dynamic range (LDR) values of two to three orders of magnitude, very low limit of detection (LOD) and limit of quantification (LOQ) values of, respectively, 0.002-0.5 ng/mL and 0.007-2.0 ng/mL, and small relative standard deviation (RSD) values of 0.2-1.7 %, according to the medium. This direct spectrofluorimetric method was applied to the evaluation of benomyl residues in natural waters, with satisfactory recovery values (87-94%).</p>

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 Determination of Capsaicin and Dihydrocapsaicin in Some Chilli Varieties using Accelerated Solvent Extraction Associated with Solid-Phase Extraction Methods and RP-HPLC-Fluorescence

2012 ◽  
Vol 9 (3) ◽  
pp. 1550-1561 ◽  
Author(s):  
Saksit Chanthai ◽  
Jureerat Juangsamoot ◽  
Chalerm Ruangviriyachai ◽  
Suchila Techawongstien
Keyword(s):  
Solvent Extraction ◽  
Solid Phase Extraction ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Accelerated Solvent Extraction ◽  
Phase Extraction ◽  
Good Precision ◽  
Real Samples ◽  
Relative Standard

Reversed phase-HPLC with fluorescence detection of two major capsaicinoids was described. Isocratic elution using a ratio of methanol and deionized water (66:34, v/v) as mobile phase was used at a flow rate of 0.9 mL/min with well achieved separation within 6 min. Under optimum conditions, their analytical figures of merit for the HPLC method were validated. The linearity was in the range of 1.0-25.0 μg/mL with multiple determination coefficients of higher than 0.995. The limit of detection was ranged of 0.008-0.01 μg/mL. The repeatability and reproducibility of the retention time and peak area for these compounds were in good precision with their relative standard deviations (RSDs) lower than 1% and 5%, respectively. Both capsaicin and dihydrocapsaicin were extracted using an accelerated solvent extraction (ASE) of methanol as an extraction solvent for 5 min static time with 3 cycles. The methanolic extracts were subjected to clean up with C18solid-phase extraction (SPE) with its recoveries ranking of 90.2-98.0%. The method recoveries of real samples were found to be 60.7-98.6%. The optimized extraction method were applied for the determination of the two capsaicinoids in ten vareities of hot chilli pepper samples. Total contents of capsaicinoids were found in the range of 2,307.0-9047.3 μg/g DW with their corresponding Scoville heat unit (SHU) of 34,600-135,700. Additionally, the contents of capsaicinoids using external calibration method comparing with those of standard addition were not significantly different, indicating accuracy of the method. Mostly, the contents of capsaicin found in these real samples were rather higher than those of dihydrocapsaicin.

scholarly journals Cloud Point Extraction and Spectrophotometric Studies for the Extraction of Nigrosin and Aniline Blue Dyes using Mixed Micelles of TBAB and Triton X-114

2021 ◽  
Vol 33 (6) ◽  
pp. 1351-1356
Author(s):  
D. Radhakrishna ◽  
D. Suneetha ◽  
P. Shyamala
Keyword(s):  
Cloud Point ◽  
Mixed Micelles ◽  
Extraction Efficiency ◽  
Cloud Point Extraction ◽  
Sea Water ◽  
Limit Of Detection ◽  
Tetrabutylammonium Bromide ◽  
Aniline Blue ◽  
Ionic Surfactant ◽  
Triton X

The extractions of two anionic dyes viz. nigrosin and aniline blue by cloud point extraction method using mixed micelles of tetrabutylammonium bromide (TBAB) and Triton X-114 were conducted. To get the greatest extraction efficiency, pH of the solution, surfactant concentration, concentration of electrolyte, equilibrium temperature and time were optimized. A linear calibration curve in the range of 0.567-9.07 mg/L (nigrosin) and 0.982-19.645 mg/L (aniline blue) was obtained. Limit of detection were found to be 2.45 ng/L and 2.008 ng/L for nigrosin and aniline blue dyes, respectively. Thermodynamic parameters were also calculated to establish the feasibility of the process. This method was then used to determine the dyes in tap and sea water samples. The extraction efficiency was explained in terms of dye surfactant interaction as shown by observed spectral changes between anionic dye and cationic surfactant followed by solubilization of the complex in non-ionic surfactant.

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