Behind some "natural" slimming teas, there's a chemical catch. FIU scientists have developed a tool to expose those hidden ingredients.
Chemistry researcher Abuzar Kabir, who has spent his career detecting chemicals that are hard to detect, recently set his sights on unregulated teas that have become readily accessible thanks to the Internet. Many, he said, are from natural and sometimes spiked with undeclared, addictive and potentially dangerous drugs. To detect if the teas had harmful chemicals, Kabir and his team turned to their go-to method: Fabric Phase Sorptive Extraction (FPSE). It relies on what appears to be a simple, small square of regular fabric. This unassuming little fabric is actually a powerhouse of analytical chemistry.
Unlike traditional lab methods that are slow and require large amounts of toxic solvents, the FPSE fabric is covered with specialized coatings. When dropped into a liquid — like a cup of brewed slimming tea — the fabric acts like a chemical magnet, selectively pulling out specific toxins, pesticides or hidden drugs.
Kabir's research has revealed that some herbal manufacturers add minuscule amounts of pharmaceutical drugs — like sibutramine or fluoxetine — to their products to ensure they produce a weight-loss effect.
"Many parts of the world are not regulated," said Kabir, noting that there could be hundreds of clandestine manufacturing units globally. Even in the U.S., he points out, the nutraceutical industry operates under much looser regulatory standards.
Though his research mainly focused on weight-loss teas, Kabir said the test can be used to analyze other liquids to detect for traces of harmfiul additives.
The potential for this fabric is nearly limitless. The technology is so efficient that it can detect even a few micrograms of a substance, Kabir said. He explains that this "selectivity" works in a similar way to how people like to mingle with other people who have similar interests. In a similar way, chemicals have an affinity to something that is similar in nature. If you dip the fabric membrane into a solution, all organic compounds that are close in their affinity chain will come in contact with the membrane and get attached by different intermolecular interactions. It's not simply a physical adhesion like an ointment; they form strong intermolecular interactions. Then, they're exposed to a very tiny amount of organic solvent to get the results.
Scientists from all across the world have found uses for these methods. Kabir jokes that when he sleeps, his technology doesn't because somebody in India or Europe is using it.
"I wake up at 3:00 a.m. to respond to their questions every day," he adds.
Kabir continues to explore new applications for the FPSE, building on a research career that has earned him a spot on the Stanford-Elsevier list, which identifies the top two percent of most-cited scholars globally. So far, the fabric has been used to monitor radiation exposure, detect an individual's exposure to different compounds, manage laboratory air and water quality, use molecularly imprinting polymers to detect cancer biomarkers in blood, and detect environmental pollution.
