2-Thiobarbituric acid as a reagent for the determination of bismuth(III) by normal and derivative spectrophotometry

Abstract

A spectrophotometric study of the reaction of 2-thiobarbituric acid (TBA ; 4,6-dihydroxy-2-mercaptopynmidine) with bismuth( 111) is presented. Bismuth(II1) forms a coloured complex with an absorbance maximum a t 416 nm with TBA in acid solution (pH 1.2-1.7). The maximum absorbance value is achieved within about 25 min. Beer's law is obeyed for a bismuth concentration of up to 10.2 p g ml-l. The molar absorptivity of the complex is 2.4 x lo* 1 mol-1 cm-l a t 416 nm and the sensitivity of the reaction is, according to Sandell's calculation, 8.7 x pg cm-2 per 0.001 absorbance unit. Cobalt (11), nickel(II), magnesium(I1) , tin (I I), lead (11) , zinc(II), barium(II), manganese(I1) and aluminium(II1) do not interfere in the determination. The same procedure can also be used for the spectrophotometric determination of copper ( 11) , which seriously interferes in the bismuth determination. A satisfactory method for the determination of bismuth in the presence of copper by derivative spectrophotometry is, however, reported.

Efficacy of dihydroxy-mercaptopyrimidine functionalized polymeric resin for the trace determination of Cd by SPE coupled flame atomic absorption spectrometry

“…36,37 Its application has been reported in the analytical eld before. 38,39 However, none of the screened literature regarding TBA has taken into account its usage in solid phase extraction as a chelating resin for the extraction of metal ions.…”

Synthesis and Evaluation of Changes Induced by Solvent and Substituent in Electronic Absorption Spectra of New Azo Disperse Dyes Containig Barbiturate Ring

“…Barbiturates are a class of drugs that are utilized as anesthetics and sleeping agents and are used for the treatment of anxiety, epilepsy, and other psychiatric disorders and possess effects on the motor and sensory functions [15]. 2-iobarbituric acid is also used in the 2-thioxo-2,3-dihydro-4,6(1H,5H)pyrimidinedione pharmacological and analytical �elds [16,17]. erefore, several studies have been published on the synthesis and spectral properties of several azo barbituric acids so far [18][19][20][21][22].…”