Samuel (Sam) I. Merenbloom, PhD

Polymers are in our packaging, clothes, consumer products, vehicles, and homes. The long list of plastic additives, including phthalates, plasticizers and antioxidants, are tied to potential and known health issues. One of the most well-known plastic additives, Bisphenol A (BPA), was ubiquitous to polycarbonate bottles until it was identified as an endocrine disruptor and phased out. More recently, environmental degradation products of bulk plastics at the nano- and micro-levels have been identified and detected in soil, water, food, and human tissues. Bioaccumulation of these particles has been associated with increased inflammation, oxidative stress, disruption of processes, and dementia, but the degree of accumulation and extent of the correlation remain to be understood.

Fluorinated polymers, such as polyfluoroalkyl substances (PFAS), used for applications including waterproofing, firefighting, cooling, cosmetics, and food packaging, have half-lives on the order of decades in the human body. The long-term effects of these compounds are just beginning to be understood. PFAS and related compounds are low-molecular weight, many are water soluble, and possess functional groups that make them easily detectible by techniques like mass spectrometry (MS). Many other fluorocarbons with no functional groups, like low- to mid-MW fragments of polytetrafluoroethylene (PTFE), come from cooking pans, sheets, and other coated products. Detection of such compounds by MS-based techniques is typically via high-energy ionization, which results in significant fragmentation, providing a fingerprint, but not a true snapshot. Analysts may know fluorocarbons are present, but do not know molecular weight, whether a compound is linear or branched, and cannot determine this information without either standards to compare to or better means of preserving and detecting intact molecules.

My work aims to expand the capabilities of mass spectrometry for the detection of intact fluorinated species using a combination of soft chemical ionization (Soft Ionization by Chemical Reaction In Transfer, SICRIT) and adduct chemistry, which has seen success for the detection of explosives and narcotics. I intend to tailor dopant chemistry to "tag" an otherwise previously unobservable (as an intact molecular ion) species, making what was once just a diagnostic fragment much more informative. Thermal desorption of species into the SICRIT will facilitate intact-molecule characterization of nano- and micro-plastic degradation in real-time. Additionally, gas chromatography coupled to SICRIT and atmospheric pressure interfaced mass spectrometers will allow migration of methods from helium to the more readily available nitrogen as a carrier gas. Researchers joining my lab will have the opportunity to conduct research utilizing chromatography, mass spectrometry, ambient ionization, chemical imaging, and ion mobility spectrometry to solve issues surrounding the detection of ubiquitous compounds with potential long-term impact on our health and well-being, as well as the health and well-being of the environment. Ultimately, I aim to make compounds that have been going undetected, or could only be detected after being obliterated, seen as they exist.