The formation of rhamnolipid complexes with metal ions of chromium (VI) and lead (II) has been studied spectrophotometrically, conductometrically, and by surface tension measurement. The values of the critical micelle concentration (CMC) of rhamnolipid, obtained by spectroscopic, conductometric, and surface tension measurements, were 5.2 × 10⁵, 5.0 × 10⁵, and 5.3 × 10⁵ mol.dm⁻³, respectively, which are in close agreement. An increase in CMC on increasing metal ion content in the rhamnolipid solution and a shift in λ_max in the spectra of rhamnolipid indicated the formation of a complex between rhamnolipid and both the metal ions, namely, chromium (VI) and lead (II). The values of stability constants for the {rhamnolipid–chromium (VI)} and {rhamnolipid–lead (II)} complexes have been determined by spectroscopic data and were as 0.58 × 10⁴ and 0.50 × 10⁴ at 308 K, respectively.

中文翻译：

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鼠李糖脂-金属离子（CrVI和PbII）配合物：分光光度法，电导率法和表面张力测量研究

分光光度法，电导法和通过表面张力测量研究了与铬（VI）和铅（II）金属离子的鼠李糖脂配合物的形成。通过光谱学，电导，和表面张力测量中获得的临界胶束浓度的鼠李糖脂（CMC），的值，分别为5.2×10 ⁵，5.0×10 ⁵，和5.3×10 ⁵ mol.dm ^-3分别，这是密切配合。鼠李糖脂溶液中金属离子含量的增加导致CMC的增加以及_{λmax的变化}鼠李糖脂的光谱中的H 2指示鼠李糖脂与两种金属离子即铬（VI）和铅（II）之间形成了络合物。{鼠李糖脂-铬（VI）}和{鼠李糖脂-铅（II）}配合物的稳定常数值已通过光谱数据确定，在308 K时分别为0.58×10 ⁴和0.50×10 ⁴。