<b>Derivative spectrophotometric determination of trace lead in alloys and biological samples after separation and preconcentration with the ion pair of 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol and ammonium tetraphenylborate on microcrystalline </b>

Abstract

ABSTRACT. Lead is quantitatively retained on 2-(5-bromo-2-pyridylazo)-5-diethylaminophenolammonium tetraphenylborate with microcrystalline naphthalene or by a column method in the pH range 4.0-6.0 from a large volume of aqueous solutions of various samples. After filtration, the solid mass consisting of the lead complex and naphthalene was dissolved with 5 mL of dimethylformamide and the metal was determined by third derivative spectrophotometry. Lead complex can alternatively be quantitatively adsorbed on ammonium tetraphenylboratenaphthalene adsorbent packed in a column and determined similarly. About 0.2 µg of lead can be concentrated in a column from 300 mL of aqueous sample, where its concentration is as low as 0.7 ng/mL. The interference of a large number of anions and cations has been studied and the optimized conditions developed have been utilized for the trace determination of lead in various samples.

Sorbent extraction of rubeanic acid–metal chelates on a new adsorbent: Sepabeads SP70

“…Main different methodologies are generally possible for the solid phase extraction of the metals: batch and column methodology [27][28][29]. Various solid phases including Chelex 100 [25], naphthalene [26], Amberlite XAD resins [27,28], synthetic polymers [30,31], polyurethane foam [32,33], C18 [34], activated carbon [35][36][37] have been used for the solid phase extraction of traces heavy metals in environmental samples prior to their instrumental analysis.…”