Spectrophotometric Determination Of Zinc Research Articles

Spectrophotometric Determination of Zinc in Food Waste Water Samples in the Presence of Surfactants Using Dithizone Method

The food waste water quality of sampling points of restaurant were collected within the Bilaspur city limit state Chhattisgarh India by determining some physicochemical parameter of the water samples using standard analytical techniques. The results of physicochemical parameters (pH, temperature, turbidity, conductivity, alkalinity, total dissolved solids, total suspended solids, total solids, Alkalinity and dissolved oxygen) revealed high variations in the concentrations of physicochemical parameters. Therefore, it is imperative that the water sources should be monitored regularly and be subjected to further treatments in order to reduce the concentrations of the few identified pollution indicators that may pose some dangers to the health of people living in this area. The aim of the present study is to develop a simpler direct uv- spectrophotometric method for the trace determination of lead with dithizone in the presence of inexpensive anionic micelles, such as sodium dodecyl sulphate (SDS), in aqueous solutions.

Spectrophotometric Determination of Zinc in Pharmaceutical Medication Samples Using 8-Hydroxyquinoline Reagent

Simple, rapid, cheap and sensitive spectrophotometric method has been described for the determination of zinc in pharmaceutical samples. The method is based on the formation of zinc- 8-Hydroxy quinoline chelate, the maximum absorption (lmax) at 384 nm. The method obeyed Beer's law in the range 1-5 mg/mL and the corresponding molar absorptivity value is 0.01578 ´ 103 L.mol-1.cm-1. The Sandell sensitivity values of limits of detection (LOD) and quantification (LOQ) was 0.381mg/mL and 1.156 mg/mL respectively. The recovery percentage of zinc was found 98.00 %, 98.96 %,99.91%, 97.50%, 98.5% and 99.30 % for (Capsule-13 mg), (Tablet-20 mg), (Tablet-40 mg),(Capsule-50 mg), (Capsule-50 mg) and (insulin vial-0.025 mg) respectively. All variable parameters has been optimized according to ICH guidelines. The limiting concentrations of some cations for interference by Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Cd(II),Sn(II) ,Pb(II), Mg(II), Ca(II) and Ba(II) are reported. The method accuracy was established by comparison with conventional flame atomic absorption spectrometric method by using t-test, ttab.= 2.571, tcal. =0.3231 at 95% confidence level, indicating the absence of systematic errors.

Cloud point extraction for separation, preconcentration and determination zinc (ii) in different pharmaceutical samples

Joining solvent extraction with cloud point extraction methods obtained a susceptible method for separation, pre-concentration, extraction and categorization of Zn (II), after forming an ion-pair association complex between Zn+2 and 4-(3-methyl phenyl azo)-4,5- diphenyl imidazole (MPADPI) with wavelength for maximum absorbance λmax.=496 Nm. This study shows optimum conditions for the formation and exaction ion-pair association complex under pH=9 and 0.5 mL Tritonx-100, 1×10-4 M (MPADPI) and heating at 80 Co for 20 minutes so that this study involved the effect of electrolyte and interferences along with the spectrophotometric determination of Zinc (II) in diverse samples.

A Novel, Donor-Active Solvent-Assisted Liquid-Phase Microextraction Procedure for Spectrometric Determination of Zinc

Based on the reaction of Zn(II), thiocyanate and 2-[2-(5-dimethylamino-thiophen-2-yl)-vinyl]-1,3,3-trimethyl-3H-indolium bromide (DTVTI), a donor-active solvent-assisted liquid-phase microextraction procedure followed by spectrophotometric determination of zinc at 570 nm was developed. The optimum experimental conditions were investigated and found to be as follows: concentration of NH4SCN 0.02 mol L-1, concentration of DTVTI 4 × 10-5 mol L-1. Various extraction solvents were studied alone as well as in mixtures with different improvers, and a mixture of toluene as the extraction solvent and tributylphosphate as the donor-active solvent in a 4:1 v/v ratio was selected. The calibration plot was linear up to 2.62 mg L-1 of zinc with limit of detection 0.09 mg L-1. The developed procedure was applied for zinc determination in dietary supplements.

Synthesis of 1-(4-Antipyrine)-3-(Sulfanilic Acid)-Triazene and Study on Determination of Zinc(II) in Water Samples by Spectrophotometry

The synthesis of a new triazene reagent 1-(4-antipyrine)-3-(sulfanilic acid)-triazene (ASTA) and is proposed as a new sensitive reagent for the extractive spectrophotometric determination of Zinc(II) was established. The results showed that in the presence of micromulsion Tween-80, ASTA could reacted with Zn ( Ⅱ) to form a red stable complex of which the molar ratio of reagent︰metal was 2︰1 in Na2B4O7-NaOH medium. The maximum absorption peak of the complex was located at 520 nm with the apparent molar absorption of 1.7×105 L•mol-1•cm-1. Beers law was obeyed in the range of 0.3～5.0 μg/10 mL for Zn (Ⅱ) and the detection limit was 0.11 mg/L. Many ions did not interfere the colour reaction system due to the existence of ammonia. This method was applied to determination of Zn (Ⅱ) in water samples, and the results were in accordance with those obtained by AAS method. Recovery was in the range of 96.5～101.5 % and the RSD(n=6) was not more than 1.4%.

Spectrophotometric Determination of Zinc in Pharmaceutical and Biological Samples with Di‐2‐pyridyl Ketone Benzoylhydrazone: a Simple, Fast, Accurate and Sensitive Method

A simple, fast, accurate, and sensitive spectrophotometric method was developed to determine zinc(II). This method is based on the reaction of Zn(II) with di‐2‐pyridyl ketone benzoylhydrazone (DPKBH), at pH=5.5 and 50% (v/v) ethanol. Beeŕs law was obeyed in the range 0.020–1.82 µg mL−1 with a molar apsorptivity of 3.64×104 L mol−1 cm−1, and a detection limit (3δ) of 2.29 µg L−1. The action of some interfering ions was verified and the developed method applied to pharmaceutical and biological samples. The results were then compared with those obtained by using a flame atomic absorption technique.

The chromatomembrane method used for sample preparations in the spectrophotometric determination of zinc and copper in pharmaceuticals

The chromatomembrane cell (CMC) was used to extract zinc and copper and to preconcentrate them for their separation from pharmaceutical preparations. The method performance was evaluated at the determination of the enrichment factor, the linearity of response, the reproducibility, the accuracy and the sensitivity. In practice a five-fold enrichment has been enough provided that sample sizes of 0.825 ml were introduced. Good linearities for zinc and copper ( r 2 > 0.99) were observed under this condition. The relative standard deviation (<3%) proved the good reproducibility of the method. The accuracy has been verified using model solutions, which were prepared from a certified reference. Recoveries of 98.8, 99.5 and 100.3% were achieved with solutions containing 0.1, 0.3 and 0.5 μg ml −1 Zn(II), respectively. In case of copper 101.2, 99.6 and 100.6% recovery were obtained for 0.1, 0.4 and 0.7 μg ml −1 Cu(II), respectively. The detection limits (three-fold of the signal-to-noise ratio) were estimated at 0.04 μg ml −1 for both. The proposed method was applied on pharmaceutical preparations and the results were found to be in a good agreement with the contents guaranteed by the producers.

Fourth derivative spectrophotometric determination of fungicide ziram (zinc(II) dimethyldithiocarbamate) in commercial samples and wheat grains

A procedure has been developed for the direct fourth derivative spectrophotometric determination of zinc(II) dimethyldithiocarbamate by converting it into its copper(II) dimethyldithiocarbamate complex, which is then dissolved in Triton X-100. Beer's law is obeyed over the concentration range 0.5–30 µg/mL in the final solution. Various parameters such as the effect of pH and the interference of a number of ions on the determination of Ziram have been studied in detail. The method is sensitive and can be used for the determination of Ziram in commercial samples like Zirax and Ziron containing Ziram and from wheat grains.

On-line separation, simultaneous dilution and spectrophotometric determination of zinc in fertilisers with a sequential injection system and xylenol orange as complexing agent

A dialyser unit, equipped with a passive neutral membrane, was incorporated into the conduits of a sequential injection (SI) system for the on-line removal of suspended solids and simultaneous dilution of the analyte before reaction and detection of the analyte. The system was applied to the determination of zinc(II) in fertilisers. The fully automated system is able to analyse zinc at a sampling frequency of ten samples per hour at a %R.S.D. of better than 0.55. The calibration graph was linear between 10 and 50 mg l −1. The detection limit was found to be 4.75 mg l −1. The results obtained with the proposed SI analyser compared favourably with the standard manual flame atomic absorption spectrometric method.

SPECTROPHOTOMETRIC DETERMINATION OF ZINC IN PHARMACEUTICAL SAMPLES USING DI-2-PYRIDYL KETONE SALICYLOYLHYDRAZONE

ABSTRACT A highly sensitive procedure for spectrophotometric determination of zinc has been developed. At pH 4.5, in 50% (V/V) ethanol-water medium and in the presence of di-2-pyridyl ketone salicyloylhydrazone (DPKSH), zinc forms a yellow complex which has maximum absorption at 376 nm The molar absorptivity is 4.82×104 L mol−1 cm−1. The detection limit of this method is 62.1 nM for Zn(II). The method has been applied to the spectrophotometric determination of zinc in pharmaceutical formulations and the results comply with those obtained by AAS. The proposed method is simple, rapid and accurate.

Spectrophotometric Determination of Zinc Using 7-(4-Nitrophenylazo)-8-Hydroxyquinoline-5-Sulfonic Acid

Um novo metodo espectrofotometrico para determinacao de zinco(II) e proposto usando um derivado da 8-hidroxiquinolina, o acido 7-(4-nitrofenilazo)-8-hidroxiquinolina sulfonico (p-NIAZOXS). A reacao entre o p-NIAZOXS e o zinco(II) e rapida em pH 9,2 e o complexo formado e estavel por pelo menos 24 h. O metodo permite a determinacao de zinco na faixa de 0,05 a 1,0 mg mL-1 com absortividade molar de 3,75 x 104 L mol-1 cm-1 e limite de deteccao de 15 ng mL-1. O metodo proposto foi aplicado na determinacao de zinco em produtos farmaceuticos e ligas de cobre, onde a precisao (R. S. D. < 2%) e exatidao obtidas foram satisfatorias.

Polyurethane foam as a sorbent for continuous flow analysis: Preconcentration and spectrophotometric determination of zinc in biological materials

A simple and accurate procedure was developed to preconcentrate and determine zinc in biological matrices. A polyurethane foam (PUF) minicolumn was used for the first time for on-line preconcentration. This system was applied to preconcentrate zinc from aqueous solutions which is sorbed as zinc–thiocyanate complex. Then, the complex was eluted by water and zinc was determined by spectrophotometry using 4-(2-pyridylazo)-resorcinol. The method was validated by the analysis of several biological certified reference materials. The detection limit was 0.9 ng ml −1 and the RSD was 1.2% for 1 min preconcentration time. Generally, concentration of Fe(III), Al(III), Mo(VI), Ni(II), Mn(II), Cu(II), and Co(II) found in biological matrices did not interfere. Dynamic ranges of concentration from 20 to 100 ng ml −1 (1 min preconcentration time) and from 5 to 20 ng ml −1 (5 min preconcentration time) achieve a sample throughput of 20 and 8 samples per hour and a preconcentration factor of 8 and 32, respectively.

Spectrophotometric determination of zinc in copper-base alloys with TAN

TAN reacts with zinc(II) forming a red complex with composition 1:2 Zn(II)-TAN and absorption maximum at 582 nm. Zinc can be determined with this reagent in the presence of Triton X-100, in the pH range 6.20-8.00 with a molar absorptivity of 4.5×104 l/mol/cm Beer's Law was obeyed up to least 1.55 μg/ml. Copper interference was eliminated with a mixture of thiosulfate and ascorbic acid and nickel separated by precipitation with dimethylglyoxime. The proposed method was used for zinc determination in several copper-base alloys and the results of analysis in comparison with certified values indicated that the procedure was accurate and precise. A derivative procedure is also proposed, allowing zinc determination with high sensitivity (5-400 ng/ml).

Spectrophotometric Determination of Zinc in Pharmaceutical Samples with Some Salicylic Azo Compounds

Abstract A sensitive spectrophotometric method for zinc has been established by reacting zinc with three salicylic acid azo dyes 2-hydroxy (Ia), 2-carboxy (Ib) and 4-(2-arsonophenylazo) salicylic acid (Ic) in universal buffer solution of pH 8.4, 7.1 and 6.0 respectively. The molar absorptivities are 1.16, 1.39 and 1.36 X 104 1/mol.cm at 515, 450 and 525 nm using reagents Ia, Ib and Ic respectively. The formed complexes have the molar ratios of zinc to ligands 1: 1 and 2: 1. Beer's law is obeyed upto 7.19 ppm of zinc whereas the optimum concentration range as evaluated by Ringbom's method is 0.5-7.00 ppm. Sandell sensitivities of the method are evaluated. The method has been used to determine zinc in various pharmaceutical products.

Spectrophotometric determination of zinc at trace level in environmental samples

Zinc is selectively extracted with N-hydroxy-N,N′-diphenylbenzamidine and spectrophotometrically determined with 4-(2-pyridylazo)resorcinol. The molar absorptivity is 9.4×104l·mol−1 cm−1. Relative standard deviation is ±1.5%.

Simultaneous spectrophotometric determination of Zinc(II) and Nickel(II) with 1-(2-pyridylazo)-2-naphthol

A new procedure for the simultaneous spectrophotometric determination of Zn(II) and Ni(II) with 1-(2-pyridylazo)-2-naphthol as chromogenic reagent has been developed. It is based on resolution of the mixed spectrum over the wavelength range 530–590 nm by applying a least-squares fitting program to standard spectra from each component. The spectra are recorded at an apparent pH of 5.0, provided by an acetate buffer in a mixed 60∶40 v/v 2-ethoxyethanol/water medium. The relative standard deviations for determination of 13.7 μg of Ni and 31.0 μg of Zn were 1.9 and 1.0%, respectively (8 replications). The method has been applied to the analysis of iron surfaces coated with a Zn-Ni alloy. The results are compared with those obtained by atomic-absorption spectrophotometry.

Some observations on the spectrophotometric determination of zinc with 1-(2-pyridylazo)-2-naphthol, diphenylguanidine, and cetyltrimethylammonium bromide, in chloroform

A spectrophotometric method for the determination of zinc is proposed. The metal reacts with 1-(2-pyridylazo)-2-naphthol (PAN) and diphenylguanidine (DFG) in the presence of Cetyltrimethylammonium bromide (CTAB) to form an orange ternary complex that can be extracted into chloroform. The optimum conditions for zinc extraction are pH 10 (borate buffer), 5 × 10 −4 M PAN, 0.2 M DFG, and 0.045% CTAB. The absorbance is measured at 555 nm (σ = 60,000 liters mol −1 cm −1) and Beer's law is obeyed up to 1.2 μg ml −1 zinc. The interference of five compounds is studied and the method is used to determine zinc in polyvinyl chloride stabilizers and zinc organic salts.

Spectrophotometric determination of zinc with hydrazidazol in the presence of Triton X-100 and its application in metal analysis

A new spectrophotometric method for the determination of zinc is proposed. The chromogenic agent Hydrazidazol forms a 1:1 chelate with zinc in the presence of Triton X-100 in a medium containing 20–40% ethanol. The molar absorptivity and conditional formation constant have been found to be 2.7 × 1O 4 l.mole −1.cm −1 (at 640 nm) and 10 5.32 respectively. Beer's law is obeyed for zinc over the range of 0.2–0.8 μg/ml with a standard deviation of 0.024 μg/ml. The method can be applied to the determination of zinc in cadmium metal and its oxide after preconcentration by selective extraction of zinc thiocyanate into ethyl acetate in the presence of EDTA and thiosulphate as masking agents.

Spectrophotometric determination of zinc in some aluminum base alloys

AbstractThe complexation of zinc with hematoxylin was studied in the presence and absence of cetyltrimethylammonium bromide (CTAB). The sensitivity of the color reaction between zinc and hematoxylin was significantly increased by the sensitizing action of CTAB. The optimum range of pH for complex formation was 7.3±8.0. The molar absorptivity of the complex was 6.3 × 104 liter mol−1 cm−1 at 610 nm and Sandell's sensitivity was 0.001 μg cm−2. Beer's law was obeyed up to 0.92 μg of zinc per ml. To determine zinc in aluminum base alloys, a preliminary solvent extraction separation of zinc from 2M hydrochloric acid solution with tri(iso‐octyl)amine in isobutyl methyl ketone was carried out.

Complexation equilibria and spectrophotometric determination of zinc (II) with 2-(4′-methyl-2′-thiazolylazo)-4,6-dimethylphenol

2-(4′-methyl-2′-thiazolylazo)-4,6-dimethylphenol has been synthesized and its acid—base behaviour (p K a 1=0.03 ± 0.01, p K a 2=9.70±0.09) and complexation equilibria with zinc (logβ 101=6.70±0.04, logβ 102 = 13.70±0.02) studied in a 40% (v / v) ethanol—water medium at I=0.25 M NaClO 4. A spectrophotometric method for the determination of 0.2–1.5 ppm of zinc has been developed (ε=1.83 × 10 4 1. mol −1 cm −1 at 590 nm) and applied to its determination in lubricating oils.