scholarly journals Magnetic Fe3O4@Mg/Al-layered double hydroxide adsorbent for preconcentration of trace metals in water matrices

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luthando Nyaba ◽  
Tshimangadzo S. Munonde ◽  
Anele Mpupa ◽  
Philiswa Nosizo Nomngongo
Keyword(s):  
Trace Metals ◽  
Layered Double Hydroxide ◽  
Inductively Coupled Plasma ◽  
Optical Emission ◽  
Environmental Water ◽  
Emission Spectrometry ◽  
Inductively Coupled ◽  
Relative Standard ◽  
Adsorption Surface ◽  
Double Hydroxide

AbstractA magnetic Fe3O4@MgAl-layered double hydroxide (MLDH) nanocomposite was successfully synthesized and applied as an effective adsorbent for preconcentration of trace As(III), Cd(II), Cr(III), Co(II), Ni(II), and Pb(II) ions from complex matrices. The quantification of the analytes was achieved using the inductively coupled plasma optical emission spectrometry (ICP-OES) technique. The nanocomposite was then characterized using BET, FTIR, SEM, and EDS. Due to its high adsorption surface area, compared to traditional metal oxide-based adsorbents, MLDH nanocomposite exhibited high extraction efficiency. Several experimental parameters controlling the preconcentration of the trace metals were optimized using response surface methodology based on central composite design. Under optimum conditions, the linearity ranged from 0.1 to 500 µg L−1 and the correlation of coefficients (R2) were higher than 0.999. The limits of detection (LODs) and quantification (LOQs) were 0.11–0.22 µg L−1 and 0.35–0.73 µg L−1, respectively. The intra-day (n = 10) and inter-day precisions (n = 5 working days) expressed in the form of percent relative standard deviations (%RSDs) were below 5%. The proposed method was successfully applied for the analysis of the As(III), Cd(II), Cr(III), Co(II), Ni(II), and Pb(II) ions in different environmental water samples.

scholarly journals Solid phase extraction and determination of indium using multiwalled carbon nanotubes modified with magnetic nanoparticles

2018 ◽  
Vol 1 (01) ◽  
pp. 5-10 ◽  
Author(s):  
Ehsan Zolfonoun
Keyword(s):  
Inductively Coupled Plasma ◽  
Solid Phase ◽  
Optical Emission ◽  
Environmental Water ◽  
Sample Volume ◽  
Emission Spectrometry ◽  
Multiwalled Carbon ◽  
Inductively Coupled ◽  
Relative Standard

In this work MWCNTs-Fe3O4 nanocomposite was used as an adsorbent for extraction and preconcentration of indium from aqueous solutions. The magnetic MWCNTs with adsorbed analytes were easily separated from the aqueous solution by applying an external magnetic field. After elution of the adsorbed analytes, the concentration of indium was determined using inductively coupled plasma optical emission spectrometry determination. The effects of pH, sorbent amount, eluent type, chelating reagent concentration, sample volume and time on the recovery of the In(III) were investigated. Under the optimum conditions, the detection limit for In(III) was 0.28 μg L−1. The precision of the method, evaluated as the relative standard deviation obtained by analyzing a series of ten replicates, was 3.1 %. The method was successfully applied for the determination of In(III) in environmental water samples.

Advances in sample digestion using microwave-ultraviolet radiations: phosphorus and sulfur determination in animal feed

2020 ◽  
Vol 16 ◽  
Author(s):  
Diogo L. R. Novo ◽  
Priscila T. Scaglioni ◽  
Rodrigo M. Pereira ◽  
Filipe S. Rondan ◽  
Gilberto S. Coelho Junior ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Animal Feed ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
Official Method ◽  
Dissolved Carbon ◽  
Inductively Coupled ◽  
Relative Standard ◽  
Wide Range ◽  
Sulfur Determination

Background: Conventional analytical methods for phosphorus and sulfur determination in several matrices present normally analytical challenges regarding inaccuracy, detectability and waste generation. Objective: The main objective is proposing a green and feasible analytical method for phosphorus and sulfur determination in animal feed. Methods: Synergic effect between microwave and ultraviolet radiations during sample preparation was evaluated for the first time for the animal feed digestion associated with further phosphorus and sulfur determination by ion chromatography with conductivity detection. Dissolved carbon and residual acidity in final digests were used for the proposed method assessment. Phosphorus and sulfur values were compared with those obtained using conventional microwave-assisted wet digestion in closed vessels associated with inductively coupled plasma optical emission spectrometry and with those obtained using Association of Official Analytical Chemists International official method. Recovery tests and certified reference material analysis were performed. Animal feeds were analyzed using the proposed method. Results: Sample masses of 500 mg were efficiently digested using only 2 mol L -1 HNO3. The results obtained by the proposed method was not differing significantly (p > 0.05) from those obtained by the conventional and official methods. Suitable recoveries (from 94 to 99%), agreement with certified values (101 and 104%) and relative standard deviations (< 8%) were achieved. Phosphorus and sulfur content in commercial products varied in a wide range (P: 5,873 to 28,387 mg kg-1 and S: 2,165 to 4,501 mg kg-1 ). Conclusion: The proposed method is a green, safe, accurate, precise and sensitive alternative for animal feed quality control.

Preparation of Urine Samples for Trace Metal Determination: A Study with Aluminium Analysis by Inductively Coupled Plasma Optical Emission Spectrometry

1998 ◽  
Vol 35 (2) ◽  
pp. 245-253 ◽  
Author(s):  
T J Burden ◽  
M W Whitehead ◽  
R P H Thompson ◽  
J J Powell
Keyword(s):  
Trace Metals ◽  
Trace Metal ◽  
Inductively Coupled Plasma ◽  
Optical Emission ◽  
Urine Samples ◽  
Emission Spectrometry ◽  
Individual Sample ◽  
Inductively Coupled ◽  
Plasma Optical Emission Spectrometry ◽  
Pooled Sample

Urinary analysis of trace metals forms a significant role in clinical chemistry, but the optimal preparation and analysis of urine samples has not been investigated. Human urine is generally supersaturated with dissolved solids. Therefore, samples often precipitate following collection. X-ray microanalysis showed that this precipitate was predominantly rich in calcium and phosphorus but could include some trace metals from urine, potentially lowering their concentrations in solution. Hence, the precipitate must be fully redissolved for accurate analysis of trace metals in urine. Methods are emphasized for the best collection and preparation of urine samples for subsequent trace metal analysis; in this work inductively coupled plasma optical emission spectrometry (ICPOES) was used for the analysis of aluminium. For optimal accuracy, peak profiles were collected over 396.147 nm-396.157 nm. Urinary aluminium levels were investigated from 10 healthy volunteers and concentrations were obtained using either aqueous, pooled or individual urine-based standard curves. Since urine has a highly variable matrix, individual sample-based standards, which are unique to that particular sample, gave the most accurate results. However, where sample size is small or sample numbers are unfeasibly large, pooled sample-based standards give good approximations to within 15% and, with appropriate validation, other elements as internal standards could also be used for approximations. Aqueous standards should be avoided. Spike-recovery experiments confirmed these data since individual sample based standards showed optimal recovery [99.3 (4.4)%], while pooled sample-based standards were a close proxy [101.6 (9.2)%] but aqueous standards were inappropriate [137.4 (12.8)%]. Postprandial urinary aluminium levels of the 10 volunteers were [7.2 (3.7)μg/L] after analysis using individual sample-based standard curves.

Determination of Ruthenium in Waste Ruthenium-Loaded Carbon Catalyst Samples Using Teflon Pressure Vessel-Assisted Sample Digestion and ICP-OES

2014 ◽  
Vol 1015 ◽  
pp. 570-573
Author(s):  
Xiao Juan Wei ◽  
Jian Ming Pan
Keyword(s):  
Inductively Coupled Plasma ◽  
Limit Of Detection ◽  
Optical Emission ◽  
Calibration Graph ◽  
Emission Spectrometry ◽  
Carbon Catalyst ◽  
Inductively Coupled ◽  
Relative Standard ◽  
Sample Dissolution

A novel method for the determination of ruthenium in waste ruthenium-loaded carbon catalyst samples was established by inductively coupled plasma optical emission spectrometry after samples digested by Teflon pressure digestion vessel with aqua regia. Such experiment conditions were investigated as the influence of sample dissolution methods, digestion time, digestion temperature and interfering ions on the determination. Under the optimized conditions, the limit of detection (LODs) of Ru for tested solution was 9 ng mL-1. The relative standard deviations (RSDs) for Ru was 2.12 % (CRu= 1 mg L-1, n = 7). The linear range of calibration graph for Ru and Zn was 0 ~ 100.00 mg L-1. The proposed method was applied to determine the practical samples with good recoveries and satisfactory results.

Simultaneous Determination of Ruthenium and Zinc in Catalysts for Hydrogenation of Benzene to Cyclohexene Using Sodium Peroxide Fusion Sample Digestion and ICP-OES

2014 ◽  
Vol 1004-1005 ◽  
pp. 1281-1284
Author(s):  
Xiao Juan Wei ◽  
Zhi Quan Tian
Keyword(s):  
Simultaneous Determination ◽  
Inductively Coupled Plasma ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
Sample Digestion ◽  
Inductively Coupled ◽  
Relative Standard ◽  
Plasma Optical Emission Spectrometry ◽  
Novel Method

A novel method for simultaneous determination of ruthenium and zinc in catalysts for hydrogenation of benzene to cyclohexene was established by inductively coupled plasma optical emission spectrometry after sample digestion by high temperature fusion with Na2O2. Such experiment conditions were investigated as the influence of sample digestion methods, fusion time, fusion temperature, the dosage of Na2O2and interfering ions on the determination. Under the optimized conditions, the limits of detection (LODs) of Ru and Zn for tested solutions were 11 and 13 ng mL-1, respectively. The relative standard deviations (RSDs) for Ru and Zn were 2.01 and 2.35 % (CRu, Zn= 1 mg L-1, n = 7), respectively. The linear ranges of calibration graphs for Ru and Zn were 0.05 ~ 100.00 mg L-1and 0.04 ~ 50.00 mg L-1, respectively. The proposed method was applied to determine catalyst samples with good recoveries and satisfactory results.

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