Spectrophotometric Determination of Cu2+ Metal Ions via Complex Formation with Carboxylated Tris(2-aminoethyl)amine

2016 ◽  
Vol 12 (3) ◽  
pp. 4237-4246
Author(s):  
Imad Odeh ◽  
Ibrahim Abu Shqair ◽  
Ziad M Shakhshir ◽  
Julnar Masharqah ◽  
Waheed J Jondi

An aminopolycarboxylic acid chelating agent; tris(2-aminoethyl)aminehexaacetic acid (TAHA) was prepared and characterized. TAHA formed stable complexes with Cu(II) ions and other metal ions at pH 10. The complexation behavior was studied by spectrophotometry at the complex maximum wavelength. Mixtures of Cu(II) and other metal ions (M2+; Ca2+, Co2+, Ni2+, Cd2+)were titrated with TAHA at pH 10. The stoichiometry of ligand - to - metal was found to be 1:1. The stability constant of Cu(II)–TAHA complex was determined to be 1.86×105 by using the continuous variation method. Beer’s law was obeyed over the concentration range 3.0×10–4 M – 1.2×10–2 M for Cu(II) solution. The results of the quantitative determination of Cu(II) gave LOD and LOQ values of 7.285×10–6 M and 2.428×10–5 M respectively. The percent relative standard deviation (%RSD) for five replicate samples was found to be 1.088% and 4.804% for Cu(II) concentrations of 1.2×10–2 M and 3.0×10–4 M respectively.

1997 ◽  
Vol 80 (2) ◽  
pp. 388-391 ◽  
Author(s):  
Ritu Kesari ◽  
Manish Rai ◽  
Vinay Kumar Gupta

Abstract A sensitive spectrophotometric method was developed for determination of paraquat, a widely used herbicide. Paraquat was reduced with glucose in an alkaline medium, and the blue radical ion obtained was measured at 600 nm. Beer’s law was obeyed at 0.1–1.2 ppm paraquat. The molar absorptivity was 1.26 × 105 L mol-1 cm-1. The standard deviation and relative standard deviation were ± 0.007 and 2.0%, respectively, for 5 μg paraquat/10 mL analyzed over 7 days. The method was free from interference by other commonly used pesticides and metal ions. The method may be used to the determine paraquat in plants, fruits, grains, water, blood, and urine.


1983 ◽  
Vol 48 (8) ◽  
pp. 2255-2262 ◽  
Author(s):  
František Vláčil ◽  
Ivan Vinš ◽  
Oldřich Malíček

Spheron DEAE (modified macroreticular hydroxyethylmethacrylate-ethylenedimethacrylate copolymer) was used for chromatographic separation and determination of Rh(III), Pd(II), and Pt(IV) in chloride medium. The most suitable composition of the mobile phase was looked for by studying the influence of hydrochloric acid concentration on the capacity ratios of the metal ions mentioned and on their resolution, as well as the influence of different additions to the mobile phase on the decrease of the high Pt(IV) retention. Using the photometric (UV) detection, the linear dependence was found up to following concentrations: Rh 200 mg l-1, Pd 2 g l-1, Pt 500 mg l-1. The detection limit was 23 ng Rh, 62 ng Pd and 96 ng Pt in 7 μl sample injected.The reproducibility of the determination was (as relative standard deviation for n = 3) 1-4%, relative error 0.7-7%.


Author(s):  
Firas Hassan Awad

This paper aims to develop a simple, sensitive and accurate spectrophotometric method for quantitative determination of paracetamol in aqueous medium. The method is based on the reaction between the hydrolyzed paracetamol and 9-chloroacridine reagent (9-CA). The spectra of the product show maximum absorption at 436 nm. Beer's law is obeyed in the concentration range of 0.25-11 µg/mL with molar absorptivity value 5.3x103 L/mol/cm. The average recovery percentage (Rec%) is 99.27% and relative standard deviation (RSD) is :: 2.82%. In addition, the stability constant has been determined and the reaction mechanism is proposed. The method has been applied successfully for the assay of paracetamol in pharmaceutical formulations. It is found that the method does not require extraction process and it agree well with British pharmacopeia.    


1980 ◽  
Vol 63 (4) ◽  
pp. 689-691
Author(s):  
Sawsan El-Masry ◽  
Raafat Soliman

Abstract A quick method for the determination of pilocarpine in eye drops in the presence of decomposition products is described. The method involves complexation of the alkaloid with bromocresol purple at pH 6. After treatment with 0.1N NaOH, the liberated dye is measured at 580 nm. The method has a relative standard deviation of 1.99%, and has been successfully applied to the analysis of 2 batches of pilocarpine eye drops. The recommended method was also used to monitor the stability of a pilocarpine nitrate solution in 0.05N NaOH at 65°C. The BPC method failed to detect any significant decomposition after 2 h incubation, but the recommended method revealed 87.5% decomposition.


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.


2003 ◽  
Vol 71 (2) ◽  
pp. 75-88
Author(s):  
Nabawia EL Guindi

The complexes of Ephedrine with Nickel, Zinc and Cadmium ions have been investigated spectrophotometricalfy using the method of corresponding solutions [I-3] and pH-metrically using Irving and Rossoti technique [4] Two compositions were observed spectrophotometrically 1 : 1 and 2: 1 (L: M) for concentration of metal ions (0.5 x 10-3 M and 1 x 10-3 M) hile the first composition only predominate at concentration of metal ions (1.5 x 10-3 M and 2 x 10-3 M ). The stability of complexes show that complexes of Ni2+ are more stable than that of Zn2+ an Cd2+, Moreover, the composition and stabilities of complexes were studied pHmetrically in aqueous medium at 0.1 M NaCl and two different temperatures 30°C and 40°C; hence the value of the free energy change (ΔG°), the enthalpy (ΔH°) and the entropy (ΔS°) were calculated at 30°C. Beside the role of Ephedrine as chelating agent to toxic elements, the complexometric method was used for the determination of Ephedrine in its pure form and in tablets.


2011 ◽  
Vol 8 (4) ◽  
pp. 996-1004
Author(s):  
Baghdad Science Journal

A sensitive and selective method have been developed for the determination of palladium (II)and platinum (II) . A new reagent and two complexes have been prepared in ethanolic solutions .The method is based on the chelation of metal ions with 4-(4?- pyrazolon azo) resorcinol (APAR) to form intense color soluble products, that are stable and have a maximum absorption at 595 nm and at 463 nm and ?max of 1.11×10 4 and.1.35 ×104 Lmole-1cm-1 for Pd(II) Pt(II) respectively. A linear correlation of (1.4 – 0.2) and (3.2 -0.4 ) ppm for pd(II) pt(II) respectively .The stability constants , relative errors , a relative standard deviations for Pd(II) and Pt(II) were 0.40×105 , 0.4×104 L mol-1 ,0.34 - 0.21% and 2.4 – 0.91% respectively. The conductivity measurements for complexes are consistent with those expected for an electrolyte. The proposed method was successfully applied to the analysis of dust and synthetic mixtures without any preliminary concentration or sparation.


Author(s):  
P.F. Collins ◽  
W.W. Lawrence ◽  
J.F. Williams

AbstractA procedure for the automated determination of ammonia in tobacco has been developed. Ammonia is extracted from the ground tobacco sample with water and is determined with a Technicon Auto Analyser system which employs separation of the ammonia through volatilization followed by colourimetry using the phenate-hypochlorite reaction. The procedure has been applied to a variety of tobaccos containing from 0.02 to 0.5 % ammonia with an overall relative standard deviation of 2 %. The accuracy of the procedure as judged by recovery tests and by comparison to a manual distillation method is considered adequate


1998 ◽  
Vol 81 (4) ◽  
pp. 763-774 ◽  
Author(s):  
Joanna M Lynch ◽  
David M Barbano ◽  
J Richard Fleming

Abstract The classic method for determination of milk casein is based on precipitation of casein at pH 4.6. Precipitated milk casein is removed by filtration and the nitrogen content of either the precipitate (direct casein method) or filtrate (noncasein nitrogen; NCN) is determined by Kjeldahl analysis. For the indirect casein method, milk total nitrogen (TN; Method 991.20) is also determined and casein is calculated as TN minus NCN. Ten laboratories tested 9 pairs of blind duplicate raw milk materials with a casein range of 2.42- 3.05℅ by both the direct and indirect casein methods. Statistical performance expressed in protein equivalents (nitrogen ⨯ 6.38) with invalid and outlier data removed was as follows: NCN method (wt%), mean = 0.762, sr = 0.010, SR = 0.016, repeatability relative standard deviation (RSDr) = 1.287℅, reproducibility relative standard deviation (RSDR) = 2.146%; indirect casein method (wt℅), mean = 2.585, repeatability = 0.015, reproducibility = 0.022, RSDr = 0.560℅, RSDR = 0.841; direct casein method (wt℅), mean = 2.575, sr = 0.015, sR = 0.025, RSDr = 0.597℅, RSDR = 0.988℅. Method performance was acceptable and comparable to similar Kjeldahl methods for determining nitrogen content of milk (Methods 991.20, 991.21,991.22, 991.23). The direct casein, indirect casein, and noncasein nitrogen methods have been adopted by AOAC INTERNATIONAL.


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