Ion-pairbased liquid–liquid extraction of gold(III) from malonate media using 2-octylaminopyridine as an extractant: analysis of alloys, minerals, and drug samples

Abstract

Liquid-liquid extraction of Au(III) from aqueous sodium malonate medium using 2-octylaminopyridine (2-OAP) as an extractant in xylene was achieved. The current work explored the influence of several experimental parameters such as pH, weak acid concentration, extractant concentration, equilibrium time, stripping agents, and aqueous:organic volume ratio on the extraction of Au(III). The experimental results showed that the Au(III) was quantitatively extracted to about 99.5% by 0.05 M 2-OAP in 0.05 M malonate at 5.0 pH. Ammonia solution was used to strip the gold-loaded organic phase and about 99.5% of Au(III) was reversibly extracted into the aqueous phase. Gold(III) was extracted into the organic phase via formation of ion-pair complex [2-OAPH + .Au (C 3 H 2 O 4) − 2 ]. The stoichiometry of the extracted species was 1:2:1 (metal: acid: extractant) determined by slope analysis. The method affords the binary, ternary mixture separation as well as separation of Au(III) from synthetic mixtures and alloys. The method is applicable for the determination and separation of gold from ayurvedic samples and recovery of gold from e-wastes. A reproduction of the method was checked by finding relative standard deviation for n = 5, which was 0.29%, and the limit of detection was 1.08 µ g/mL.

2(4)-Aminopyridines as Ligands in the Coordination and Extraction Chemistry of Platinum Metals

“…Ro (III) is extracted from citrate solutions with 2-dodecylaminopyridine [17], and from Ru (III) succinate solutions with 2-OAP [18]. From acetate solutions, 2-OAP extracts Ir (III) [19] from malonate -Au (III) [20]. 2-OAP and other metals are extracted in the form of ionic associates from chloride, malonate, succinate, salicylate, citrate media: To (IV) [21], Zr (IV) [22], V (V) [23], Mo (VI) [24], Cr (VI) [25], Bi (III) [26], Ga (III) [27], Tl (III) [28], Sm (III) [29], Hg (II) [30].…”

Liquid- Liquid Extraction of Zinc(II) From Acid Media with N-N-Heptylaniline as an Extractant: Analysis of Pharmaceutical and Commercial Sample

“…An accurate, inexpensive and less laborious liquid-liquid extractive spectrophotometric procedure for the determination of zinc(II) in aqueous media has been developed [25]. Previously we have reported number of solvent extraction methods for the quantitative extraction of platinum group metals with amines [26][27][28][29][30][31][32][33][34][35][36][37][38][39]. In present research paper a systematic study of extraction of zinc(II) with N-n-heptylaniline in xylene has been carried out.…”

Highly proficient extraction separation of thorium(IV) from sulfuric acid solution using N-n-decylaniline: real sample analysis

“…Previously we have reported number of solvent extraction methods for the extraction separation and determination of other metal ions [25][26][27][28][29][30][31][32][33]. Here, we report the extraction behavior of thorium(IV) from H 2 SO 4 media by using N-n-decylaniline as an extractant.…”