Spectrophotometric Determination of Cobalt(II) with Mordant Blue 9 -Application to Vitamin B12 (Injections and Powder)

Abstract

A spectrophotometric method has been developed for determination of cobalt with Mordant Blue 9 in presence of cetyltrimethylammonium bromide (CTAB) in order to form an intense violet-colored chelate which exhibits maximum absorption at 586 nm at pH 3. Beer's law is obeyed over the range of 0.004-1 ppm with a molar absorptivity 3.97×10 4 l.mol-1 .cm-1 , Sandell's sensitivity index of 1.484 ng.cm-2 , while LOD (limit of dedication), LOQ (limit of quantitation) are found to be 4.006 ng/ml (n=10) and 13.353 ng/ml (n=10), respectively. The method has been applied for determination of Co(II) in pharmaceutical preparations. Keywords: cobalt, Mordant Blue9, vitamin B 12 , CTAB, spectrophotometry. ‫ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬ ‫ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬ ‫ــــ‬ ‫ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬ ‫ــــــــــــــــــــــــــ‬ ‫ـ‬ (‫الكوبلت‬ ‫لفلز‬ ‫الطيفي‬ ‫التقدير‬ II ‫الموردنات‬ ‫كاشف‬ ‫مع‬) ‫األزرق‬ 9-‫فيتامين‬ ‫على‬ ‫التطبيق‬ B 12 ‫(الباودر‬ ‫اإلبر‬ ‫و‬) ‫الملخص‬ ‫تتد‬ ‫ت‬ ‫و‬ ‫و‬ ‫ك‬ ‫ال‬ ‫و‬ ‫و‬ ‫ك‬ ‫وب‬ ‫و‬ ‫افاع‬ ‫وط‬ ‫و‬ ‫تتد‬ ‫ت‬ ‫وبة‬ ‫و‬ ‫ا‬ ‫وف‬ ‫و‬ ‫طةلة‬ ‫وف‬ ‫و‬ ‫ة‬ ‫ط‬ ‫ط‬ ‫وت‬ ‫و‬ ‫ط‬ ‫و‬ ‫و‬ ‫ت‬ ‫وش‬ ‫و‬ ‫ع‬ ‫وط‬ ‫و‬ Mordant blue 9 ‫وب‬ ‫و‬ ‫عف‬ ‫وتةم‬ ‫و‬ ‫ات‬ ‫و‬ ‫و‬ ‫ةا‬ ‫تة‬ ‫وتب‬ ‫ودتي‬ ‫وتم‬ ‫ت‬ ‫وي‬ ‫دنلس‬ CTAB ‫وط)ة‬ ‫س‬ ‫وف‬ ‫عف‬ ‫ب‬ ‫و‬ ‫تع‬ ‫وتي‬ ‫ع‬ ‫وت‬ ‫ط‬ ‫وب‬ ‫كن‬ ‫د‬ ‫و‬ ‫تعا‬ ‫و‬ ‫عك‬ ‫و‬ ‫عكط‬ ‫وي‬ ‫ت‬ ‫ت‬ 586 ‫وب‬ ‫كن‬ ‫نتعةا‬ ‫و‬ ‫ن‬ pH 3 ‫و‬ ‫و‬ ‫و‬ ‫و‬ ‫تة‬ ‫ا‬ ‫ت‬ ‫وب‬ ‫و‬ ‫و‬ ‫و‬ ‫ع‬ ‫و‬ ‫و‬ ‫و‬ ‫و‬ ‫ع‬ ‫و‬ ‫و‬ ‫و‬ ‫و‬ ‫دة‬ ‫نتم‬ ‫و‬ ‫و‬ ‫و‬ ‫و‬ ‫وف‬ ‫و‬ ‫و‬ ‫و‬ ‫اطدة‬ ‫وبتب‬ ‫و‬ ‫و‬ ‫و‬) ‫وط‬ ‫و‬ ‫و‬ ‫و‬ ‫ن‬ ‫تت‬-0.004 ‫و‬ ‫و‬ ‫و‬ ‫و‬ ‫ي‬ ‫وف‬ ‫و‬ ‫و‬ ‫و‬ ‫ة‬ ‫عتة‬ ‫ت‬ ‫وةف‬ ‫و‬ ‫و‬ ‫و‬ ‫تةعا‬ ‫وط‬ ‫و‬ ‫و‬ ‫و‬ ‫ن‬ ‫تت‬ ‫وط‬ ‫و‬ ‫و‬ ‫و‬ ‫تتد‬ ‫ت‬ ‫وم‬ ‫و‬ ‫و‬ ‫و‬ ‫ع‬ ‫ةتم‬ ‫ع‬ ‫و‬ ‫و‬ ‫و‬ ‫و‬ ‫د‬ 10 4 ‫.عت‬ ‫ا‬-1 ‫و‬ ‫.س‬-1 ‫وةف‬ ‫س‬ ‫)س‬ ‫نب‬ ‫و‬ ‫س‬ ‫وف‬ ‫تبة‬ 1.484 ‫و‬ ‫/س‬ ‫ت‬ ‫نتغ‬ ‫ن‬ 2 ‫و‬ ‫ت‬ ‫ت‬ ‫وب‬) ‫ت‬ 4.006 ‫و‬ ‫/ع‬ ‫ت‬ ‫نتغ‬ ‫ن‬ (n=10) ‫و‬ ‫تع‬ ‫ت‬ ‫وب‬) ‫ت‬ ‫ت‬ 13.353 ‫/ع‬ ‫ت‬ ‫نتغ‬ ‫ن‬ (n=10) .‫لف‬ ‫عخا‬ ‫ةبةنةف‬ ‫تط‬ ‫عسا)ض‬ ‫ع‬ ‫ط‬ ‫تتد‬ ‫ت‬ ‫بة‬ ‫ا‬ ‫ع‬ ‫ح‬ ‫تدني‬ ‫ف‬ ‫ة‬ ‫ط‬ ‫ت‬ ‫اطدةف‬ ‫ا‬ ‫ب‬ ‫ت‬. ‫الدالة‬ ‫الكلمات‬ : ‫و‬ ‫ط‬ ‫تتد‬ ‫ت‬ ‫ع‬ II ، ‫عت‬ ‫ت‬ ‫ت‬ ‫ط‬ ‫بن‬ ‫ف‬ ‫تأل‬ 9 ، ‫عةم‬ ‫عةا‬ B 12 ، ‫طةل‬ ‫ت‬ ‫بة‬ ‫ا‬ ‫ت‬ ، CTAB. ‫ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬ ‫ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬ ‫ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬ ‫ـــــــــــــــــــــــــــــــــــــــــــــ‬ ‫ـ‬ INTRODUCTION Cobalt is an essential element in human body as a component of vitamin B 12 and it is clear that monitoring of body fluids for cobalt is essential for the control of nutritional deficiencies, and perhaps prevention of its toxic effect in cases of occupational exposure (Todorovska et al., 2003). Although cobalt is not highly toxic, but its acute and chronic poisoning gives rise to symptoms such as pulmonary edema, nausea, allergy, gastro-intestinal tract disorders, diarrhea and other disorders (Gupta et al., 2004). Cobalt (II) ions are also genotoxic and carcinogenic (Ahmed and Hossan, 2008). This metal ion is among the significant toxic metals for environmental surveillance food control occupational medicine, toxicology and hygiene (Enafi et al., 2000). Cobalt (II) has also been employed in the production of sensors (Oiye et al., 2009; Pedrosa and Berttoi, 2007) and alloy (Hamood and Abed, 2012). Cobalt occurs predominantly in the II oxidation state. In some complexes, it is readily oxidized to Co(III). It forms amine, cyanide, tartrate and EDTA complexes (Marcezonko and Balcerzak, 2000).