Simultaneous Spectrophotometric Determination Of Copper Research Articles

Simultaneous spectrophotometric determination of copper, cobalt, nickel and iron in foodstuffs and vegetables with a new bis thiosemicarbazone ligand using chemometric approaches

A newly synthesized bis thiosemicarbazone ligand, (2Z,2′Z)-2,2′-((4S,5R)-4,5,6-trihydroxyhexane-1,2-diylidene)bis(N-phenylhydrazinecarbothioamide), was used to make a complex with Cu2+, Ni2+, Co2+ and Fe3+ for their simultaneous spectrophotometric determination using chemometric methods. By Job’s method, the ratio of metal to ligand in Ni2+ was found to be 1:2, whereas it was 1:4 for the others. The effect of pH on the sensitivity and selectivity of the formed complexes was studied according to the net analyte signal (NAS). Under optimum conditions, the calibration graphs were linear in the ranges of 0.10–3.83, 0.20–3.83, 0.23–5.23 and 0.32–8.12mgL−1 with the detection limits of 2, 3, 4 and 10μgL−1 for Cu2+, Co2+, Ni2+ and Fe3+ respectively. The OSC-PLS1 for Cu2+ and Ni2+, the PLS1 for Co2+ and the PC-FFANN for Fe3+ were selected as the best models. The selected models were successfully applied for the simultaneous determination of elements in some foodstuffs and vegetables.

Preconcentration and simultaneous spectrophotometric determination of copper and mercury by dispersive liquid–liquid microextraction and orthogonal signal correction–partial least squares

A new method for spectrophotometric simultaneous determination of copper and mercury was developed by the dispersive liquid–liquid microextraction (DLLME) preconcentration and orthogonal signal correction–partial least squares (OSC–PLS). In the proposed method, dithizone was used as a chelating agent, and carbon tetrachloride and acetonitrile were selected as extraction and dispersive solvents. All factors affecting the sensitivity were optimized by the Box–Behnken design and the linear dynamic range for determination of copper and mercury was found. Under the optimum conditions, the calibration graphs were linear in the range of 10.0–250.0 and 10–300ngmL−1 with detection limit of 2.6 and 2.8ngmL−1 (3δB/m) and the enrichment factor of this method for copper and mercury, reached 180 and 175, respectively. The simultaneous determination of copper and mercury by using spectrophotometric methods is a difficult problem, due to the spectral interferences. The PLS modeling was used for the multivariate calibration of the spectrophotometric data. The OSC was used for preprocessing of data matrices and the prediction results of model, with and without using OSC, were statistically compared. The experimental calibration matrix was designed by measuring the absorbance over the range of 400–700nm for 25 samples. The root mean squares error of prediction for copper and mercury with and without OSC was 0.010, 0.026 and 0.055, 0.086, respectively. The proposed method was successfully applied for the simultaneous determination of copper and mercury in spiked water and synthesis samples.

화학계량학적 방법을 사용한 Triton X-100이 함유된 1-(2-Thiazolylazo)-2-Naphthol을 사용한 구리, 니켈과 아연의 동시 분광광도법적 정량

Triton X-100이 함유된 상태에서 정색시약인 1-(2-thiazolylazo)-2-naphthol이 첨가된 물에서 구리 (II), 니켈(II)과 아연(II)의 동시 분광광도법적 정량을 위한 다변량 모델들이 개발되었다. 분광학적 간섭의 단점을 극복하기 위해서, 주성분회귀분석법(PCR)과 부분최소자승법(PLS) 다변량 분석법적 접근이 적용되었다. 다양한 시험 세트를 사용하여 본 방법의 수행이 입증되었고 그 결과들이 비교되었다. 일반적으로 PLS와 PCR 모델들 사이에 분석적 수행에서의 심각한 차이가 없었다. <TEX>$Cu^{2+}$</TEX>, <TEX>$Ni^{2+}$</TEX> and <TEX>$Zn^{2+}$</TEX> 의 세 성분들을 사용한 예측의 제곱근 평균 제곱 오차(RMSEP)들은 각각 0.018, 0.010, 0.011 ppm이었다. 또한 감도, 분석감도, 검출한계(LOD)와 같은 가치들의 측면들이 평가되었다. 본 논문에서 제안하는 과정이 화합물 혼합용액과 수돗물 속의 <TEX>$Cu^{2+}$</TEX>, <TEX>$Ni^{2+}$</TEX> and <TEX>$Zn^{2+}$</TEX>의 동시 검출에 적용되었을 때에 높은 신뢰도가 성취되었다. Multivariate models were developed for the simultaneous spectrophotometric determination of copper (II), nickel (II) and zinc (II) in water with 1-(2-thiazolylazo)-2-naphthol as chromogenic reagent in the presence of Triton X-100. To overcome the drawback of spectral interferences, principal component regression (PCR) and partial least square (PLS) multivariate calibration approaches were applied. Performances were validated with several test sets, and their results were then compared. In general, no significant difference in analytical performance between PLS and PCR models. The root mean square error of prediction (RMSEP) using three components for <TEX>$Cu^{2+}$</TEX>, <TEX>$Ni^{2+}$</TEX> and <TEX>$Zn^{2+}$</TEX> were 0.018, 0.010, 0.011 ppm, respectively. Figures of merit such as sensitivity, analytical sensitivity, limit of detection (LOD) were also estimated. High reliability was achieved when the proposed procedure was applied to simultaneous determination of <TEX>$Cu^{2+}$</TEX>, <TEX>$Ni^{2+}$</TEX> and <TEX>$Zn^{2+}$</TEX> in synthetic mixture and tap water.

Application of Multivariate Calibration Techniques to Simultaneous Spectrophotometric Determination of Copper and Iron Using 1‐(2‐Pyridylazo)‐2‐naphthol in AOT Micellar Solution

AbstractMultivariate calibration models (PCR and PLS) were developed for simultaneous determination of Fe(III) and Cu(II) with 1‐(2‐pyridylazo)‐2‐naphthol and AOT as chromogenic reagent and micellizing agent, respectively. In the presence of AOT the spectrum of Fe(III)‐PAN complex was shifted to higher wavelength and the overlapping with Cu‐PAN spectrum decreased. It seems that this anionic surfactant enters the structure of the Fe‐PAN complex to cause a shift in the absorption spectrum of it. The parameters controlling behavior of the systems were investigated and optimum conditions were selected. Sixteen ternary mixtures were selected as the calibration set. To select the number of factors in PCR and PLS algorithms, a cross validation method, leaving out one sample at a time, was employed. The calibration models were validated with 8 synthetic mixtures containing the metal ions in different proportions that were randomly designed. The best calibration model was obtained by using PLS regression. The method was successfully applied to simultaneous determination of copper and iron in biological samples.

Simultaneous spectrophotometric determination of copper(II) and zinc(II) based on their kinetic separation in flow-injection systems

Flow-injection methods are developed for the spectrophotometric analysis of binary copper(II) and zinc(II) mixtures. They are based on measurements of a differential kinetic signal caused by ligand-exchange reactions that occur in the flow between the complexes of these metals with the same chromogenic reagent (4-(2-pyridylazo)-resorcinol or zincon) and aminopolycarboxylic acids. Two different approaches are used for the kinetic separation (or masking) of these metals followed by the on-line processing of the recorded signal by regression analysis. One of them is monitoring an indicator reaction in the stopped-flow mode, and the other is recording the separated peaks in the flow-injection system with two reaction zones reaching the detector over certain periods. The optimum detection conditions were found (cmin = 0.03 μg/mL), which allow the detection of the studied metal ions in mixtures in a ratio of no more than 1: 5 with a relative error of no more than 5%, good precision (RSD < 10%, n = 6, P = 0.95), and high throughput (90 h−1). The developed procedures were tested in the analysis of model mixtures and pharmaceutical preparations.

One-shot flow injection spectrophotometric simultaneous determination of copper, iron and zinc in patients’ sera with newly developed multi-compartment flow cell

We propose here an affordable flow injection method for simultaneous spectrophotometric determination of copper, iron and zinc in patients’ sera. The use of a newly designed multi-compartment flow cell allowed the simultaneous determination of the three metals with a single injection (‘one-shot’) and a double beam spectrophotometer. The chemistry relied on the reactions of these metals with 2-(5-nitro-2-pyridylazo)-5-[ N-propyl- N-(3-sulfopropyl)amino]phenol (nitro-PAPS) to form corresponding colored complexes. At pH 3.8, only copper–nitro-PAPS complex was formed in the presence of pyrophosphate as a masking agent for iron, and then the copper and iron(II) complexes were formed in the presence of reductant (ascorbic acid) at the same pH, and finally all three metals reacted with nitro-PAPS at pH 8.6. The characteristics were introduced into the flow system to determine each metal selectively and sensitively. Under the optimum conditions, linear calibration curves for the three metals were obtained in the range of 0.01–1 mg L −1 with a sample throughput rate of 20 h −1. The limits of detection (3 σ) were 3.9 μg L −1 for copper, 4.1 μg L −1 for iron and 4.0 μg L −1 for zinc. The proposed method was applied to analysis of some patients’ sera.

Sequential injection lab-on-valve simultaneous spectrophotometric determination of trace amounts of copper and iron

A sequential injection (SI) method in a lab-on-valve (LOV) format for simultaneous spectrophotometric determination of copper and iron has been devised. The detection chemistry is based on the complex formation of 2-(5-bromo-2-pyridylazo)-5-[ N- n-propyl- N-(3-sulfopropyl)amino]aniline (5-Br-PSAA) with copper(II) and/or iron(II) at pH 4.6. Copper(II) reacts with 5-Br-PSAA to form the complex which has an absorption maximum at 580 nm but iron(III) does not react. In the presence of a reducing agent only iron(II)–5-Br-PSAA complex is formed and detected at 558 nm. Under the optimum experimental conditions, the determinable ranges are 0.1–2 mg l −1 for copper and 0.1–5 mg l −1 for iron, respectively, with a sampling rate of 18 h −1. The limits of detection are 50 μg l −1 for copper and 25 μg l −1 for iron. The relative standard deviations ( n = 15) are 2% for 0.5 mg l −1 copper and 1.8% for 0.5 mg l −1 iron when determined in standard solutions. The recoveries range between 96 and 105% when determining 0.25–2 mg l −1 of copper and 0.2–5 mg l −1 of iron in artificial mixtures at copper/iron ratios of 1:10 to 5:1. The proposed SI-LOV method is successfully applied to the simultaneous determination of copper and iron in multi-element standard solution and in industrial wastewater samples.

Analytical properties of 1-phenyl-1,2-propanedione-2-oxime thiosemicarbazone: simultaneous spectrophotometric determination of copper(II) and nickel(II) in edible oils and seeds

The analytical properties of 1-phenyl-1,2-propanedione-2-oxime thiosemi-carbazone (PPDOT) are described for the first time. The reagent gives colour reactions with copper(II) and nickel(II) in sodium acetate-acetic acid buffer medium. The copper complex shows maximum absorbance at 465 nm while the nickel complex at 395 nm. Therefore, these colour reactions have been advantageously used for the simultaneous spectrophotometric determination of copper(II) and nickel(II) in synthetic mixture and also in edible oils and seeds.

Simultaneous spectrophotometric determination of copper(II), vanadium(V), and iron(III) using 2-hydroxy-1-naphthaldehyde benzoylhydrazone

A simple and new simultaneous spectrophotometric method is proposed for the analysis of a three-component system containing Cu(II), V(V) and Fe(III) without separation using 2-hydroxy-1-naphthaldehyde benzoylhydrazone (OHNABH). The reagent reacts with all the three metal ions at pH 5, forming soluble colored species in 30% DMF. The physico-chemical characteristics, statistical analysis and application of the method for the analysis of complex materials are reported. The effect of diverse ions and the stoichiometry and stability constants are also studied.

Simultaneous Spectrophotometric Determination of Copper(II) and Nickel(II) as Complexes with Sodium Diethyldithiocarbamate in an Anionic Micellar Medium Using Partial Least-Squares Regression

A spectrophotometric method for the simultaneous determination of copper and nickel by the use of diethyldithiocarbamate (DDTC) as a chelating agent in the presence of aqueous anionic micellar medium of sodium dodecyl sulfate (SDS) was developed. The presence of micellar systems allow one to eliminate the solvent extraction step necessary for the determination of metal–DDTC complexes in the absence of micelles. This reduces the cost and toxicity of the method. The influence of chemical variables affecting the analytical reaction was evaluated. A partial least-squares procedure was used to access data obtained from the calibration solutions. The ensuing method was validated by applying it to the analysis of synthetic mixtures over the concentration ranges 0–286 μmol Cu/ml and 0–619 μmol Ni/ml. The relative errors in determinations were less than 5% in most cases. The proposed method was applied to the determination of Cu and Ni in metal alloys.

Multicommutation in flow analysis. Part 4. Computer-assisted splitting for spectrophotometric determination of copper and zinc in plants

An improved splitting process in flow analysis accomplished by means of a computer controlled three-way solenoid valve is proposed. This valve is located at the splitting site, and defines the flow pattern and the portions of the processed sample delivered to each emergent stream. As an application, the simultaneous spectrophotometric determination of copper and zinc in plant digests was selected. The method is based on metal complexation with cyanide, differential kinetics of decomplexation, and reaction with Zincon. The proposed system is very stable and handles 45 samples per hour which corresponds to 0.27 mg Zincon per determination. Precise measurements (r.s.d. = 0.7% and 1.7% for first and second peaks) are obtained within 0.00–1.00 mg 1 −1 Cu and 0.00–2.00 mg 1 −1 Zn. Detection limits are 0.05 and 0.04 mg l −1 for Cu and Zn. Results are in agreement with standard reference materials.

Simultaneous spectrophotometric determination of copper(II), lead(II)and cadrnium(II)

The full spectrum technique in the fourier domain was studied for simultaneous determination of Cu(II), Pb(II) and Cd(II) with 4-(2-pyridylazo) resorcinol (PAR). A program called SPGRFSQ. was designed to perform the calculations. Seven error functions were calculated for deducing the number of factors. Data reduction was performed using principal component analysis (PCA) algorithm. Experimental results showed the method to be successful even where there was severe overlap of spectra.

Simultaneous spectrophotometric determination of copper, nickel and palladium by flow injection analysis

A flow injection method has been developed for the simultaneous spectrophotometric determination of ternary and binary mixtures of copper, nickel and palladium. The system involves the sequential measurement of the absorbances of the metal-EDTA complexes at 700, 590, 380 and 340 nm. Sample solutions were buffered at pH 3.2 using a phthalate buffer. The EDTA carrier stream and samples contained 0.5 M sodium nitrate solution and the phthalate concentration in samples was adjusted to 0.08 M to minimise refractive index effects. Solutions could be analysed at rates of up to 100 h–1, and the relative standard deviation was less than 1%. The effects of the length of the dispersion coil and the sample volume on the FIA-spectrophotometric signals are presented.

Simultaneous spectrophotometric determination of copper(II) and iron(III) as the azide complexes

The simultaneous spetrophotometric determination of copper and iron is based on the yellow and red azide complexes formed in 50% (v/v) water/acetone medium. Absorbances are measured at 345 and 435 nm where molar absorptivities for the iron(III) complex are 8.77 × 10 3 and 8.49 × 10 3 l mol −1 cm −1, rspectively, and absorptivities for the copper(II) complexes are 1.47 × 10 3 and 5.69 × 10 3 l mol −1 cm −1, respectively. The systems obey Beer's law and concentrations as low as 2.0 and 1.2 mg l −1 for copper and iron, respectively, can be quantified in a 1.00-cm cell. Determination of iron(III) in 23 mixtures (1.1–5.4 mg l −1) yielded a relative standard deviation of 0.86%; similar data for copper(II) (2.0–8.9 mg l −1) yielded a relative standard deviation of 1.6%.

Simultaneous spectrophotometric determination of copper, cobalt, nickel, and chromium

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSimultaneous spectrophotometric determination of copper, cobalt, nickel, and chromiumVaughn K. Gustin and Thomas R. SweetCite this: Anal. Chem. 1961, 33, 13, 1942–1944Publication Date (Print):December 1, 1961Publication History Published online1 May 2002Published inissue 1 December 1961https://doi.org/10.1021/ac50154a049RIGHTS & PERMISSIONSArticle Views113Altmetric-Citations5LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (444 KB) Get e-Alerts Get e-Alerts

The simultaneous spectrophotometric determination of copper and nickel in low-alloy steels

The simultaneous spectrophotometric determination of copper and nickel in low-alloy steels