Spectrophotometric Determination of Iron(II) and Cobalt(II) by Direct, Derivative, and Simultaneous Methods Using 2-Hydroxy-1-Naphthaldehyde-p-Hydroxybenzoichydrazone

Abstract

Optimized and validated spectrophotometric methods have been proposed for the determination of iron and cobalt individually and simultaneously. 2-hydroxy-1-naphthaldehyde-p-hydroxybenzoichydrazone (HNAHBH) reacts with iron(II) and cobalt(II) to form reddish-brown and yellow-coloured [Fe(II)-HNAHBH] and [Co(II)-HNAHBH] complexes, respectively. The maximum absorbance of these complexes was found at 405 nm and 425 nm, respectively. For [Fe(II)-HNAHBH], Beer's law is obeyed over the concentration range of 0.055–1.373 μg mL−1 with a detection limit of 0.095 μg mL−1 and molar absorptivity ɛ, 5.6 × 104 L mol−1 cm−1. [Co(II)-HNAHBH] complex obeys Beer's law in 0.118–3.534 μg mL−1 range with a detection limit of 0.04 μg mL−1 and molar absorptivity, ɛ of 2.3 × 104 L mol−1 cm−1. Highly sensitive and selective first-, second- and third-order derivative methods are described for the determination of iron and cobalt. A simultaneous second-order derivative spectrophotometric method is proposed for the determination of these metals. All the proposed methods are successfully employed in the analysis of various biological, water, and alloy samples for the determination of iron and cobalt content.

Spectrophotometric Determination of Cu (+II) by Complexation with 2-(4-biphenyl) Imidazo [1,2-] Pyrimidine-3-Hydrazone and Studying Characteristics of prepared complex.

“…The resulted solution was heated gently near dryness, and then 5ml sulfuric acid (diluted with water in 1:1 ratio) was added to convert white solid to blue solution because of the formation of hydrated copper sulfate. The solution was filtered and the volume is completed to 100ml with distilled water [18]. 1 ml of this stock solution was transferred volumetric flask of 50ml, diluted with deionized and by adding slowly and carefully few drops(approximately 0.5ml) of concentrated sodium hydroxide to prevent precipitation of blue copper hydroxide (at suitable hydroxide concentration) and to neutralize strong acidic medium (pH=1) which reduces color intensity of complex, the volume is completed to 50ml .…”

“…The mixture was reheated for 20-25 minutes. The content was cooled, filtered and neutralized with ammonium hydroxide in presence 1.5ml of 0.01% sodium tartrate, then the content was poured into 10ml volumetric flasks and diluted with water [18]. Equal volumes (1ml) of urine solution and standard solution of copper sulfate (5,10,20) ppm were added to 2ml of 2000ppm BIPH, and volume was completed to 5ml with deionized water.…”

Investiagtion of Crystal Structure and Analytical Opportunities of 3 - (4'-Fluorophenylimine) - 1 - Phenylbutanon – 1

“…Numerous organic reagents for spectrophotometric determination of iron (III) are known [1][2][3][4][5][6][7]. Among them, β-diketones and related derivatives with their selectivity are different from others [8,9].…”

New oxidative electrophilic coupling reactions and their application to spectrophotometric determination of iron(III) in environmental waters, soils and industrial effluent samples

“…Moreover, there are visible spectrophotometry amongst the optical methods seems to be the most appropriate analytical approach for the determination of iron, as it provides sensitive, precise and accurate measurements of suitable analytes, and offers practical and economical advantages over other methods. However, some of the recently proposed spectrophotometric methods [31] for the determination of iron [32][33][34][35][36][37][38][39] are less sensitive and less selective.…”