Rapid Solvent Extraction and Direct Spectrophotometric Determination of Lead(II) with 1,1,1-Trifluoro-4-(2-thienyl)-4-mercaptobut-3-en-2-one

Abstract The thio derivative of 2-thenoyltrifluoroacetone 1,1,1-trifluoro-4-(2-thienyl)-4-mercaptobut-3-en-2-one (STTA) is used for the simultaneous extraction and direct colorimetric determination of lead. About 100 μg of lead is quantitatively extracted, at pH 6.5, with 10 ml of 0.0020m STTA-CCl4 as a bright orange colored complex, which can be measured spectrophotometrically at 480 nm. The system conforms to Beer’s law over the concentration range of 1–40 μ/ml of lead(II). The color of the complex is stable for 60 hr. Lead can be quantitatively extracted and determined in the presence of a number of ions. The method is made selective by using some sequestering agents and carrying out selective extractions with mesityl oxide. The procedure is found to be suitable for the analysis of lead in gun metal and solder.