Aqueous two-phase extraction (ATPE) is a flexible technique for the purification of quite a few chemical compounds and supplies, starting from proteins and nucleic acids to cell organelles and numerous nanostructures. Nonetheless, regardless of its widespread use, the underlying extraction mechanism stays unclear, which considerably reduces the utility of ATPE. Many forms of surfactants are sometimes added to biphasic techniques to boost the extraction of analytes between phases. Though their position on this course of is essential, it’s not fully understood. On this work, to fill this hole, we adapt and refine a virtually two-hundred-year-old chemical method for the detection of bile salts in urine, known as Pettenkofer’s check and monitor the partitioning of single-walled carbon nanotubes (SWCNTs) by ATPE. This method enabled us to tint the in any other case clear bile salt surfactants to exactly monitor their distribution and focus within the biphasic system, thereby unravelling the modus operandi of this widespread purification method.
