Nelson Vinueza Benitez

Drugs that increase protein stability represent an important new source of therapeutics. With Dr. Jason Gestwicki (UCSF) as Principal Investigator, this proposal aims at developing next-generation Differential Scanning Fluorimetry (DSF) with a series of disruptive technical advances to improve the robustness, utility and scope of DSF, focusing on key innovations of: (i) dramatically expanding the chemical diversity and specificity of DSF chemical dyes and (ii) improving the robustness of data-fitting algorithms.

Around 10 million tons of post-consumer textile waste (PCTW) are disposed of in U.S. landfills annually, 8% of all municipal solid waste. PCTW is landfilled because it contains complex blends of natural and synthetic fibers that are not easy to recycle as well as dyes and other chemicals that interfere with reuse. Microbial communities in anaerobic digesters (AD) have the potential to convert natural fibers in PCTW to a useful biofuel, biomethane, as well as degrade associated dyes and chemicals. By gently deconstructing and separating PCTW into less complex material streams, it will be possible to recover valuable non-degraded fibers, generate co-products and efficiently treat residuals to divert PCTW from landfills. The goal of this project is to use mild enzymatic methods to convert PCTW from large heavy solids to pumpable slurries with compositions that are compatible with microbial growth in AD, while recovering non-degraded fractions for recycling.

The main purpose of this project is to develop mass spectrometry methodologies and a database in combination with liquid chromatography and ambient ionization techniques for the identification, prediction, and structural elucidation of dyes and their degradations products.

The characterization and analysis of trace evidence is part of the standard protocol during forensic investigations. Trace evidence can potentially be used to link a suspect with a victim, or a suspect/ victim with a location. Textile fibers are one type of trace evidence, and the color of the fiber is one of the its most important properties. Fibers are typically analyzed using a variety of techniques and compared with a reference. First, nondestructive techniques such as light microscopy and UV/Vis microspectrophotometry are used. If these don??????????????????t yield conclusive results, destructive techniques such as thin-layer chromatography and gas-chromatography mass spectrometry are used. Recently, Raman spectroscopy has been evaluated as an analytical tool for the characterization of fibers. Besides its non-destructive nature, Raman spectroscopy offers other advantages such as: requiring almost no sample preparation, yielding more distinctive spectra than UV/VIS/NIR spectra, and providing unique sample information. While Raman spectroscopy is a promising tool, it has its own set of limitations, with the main one being sample fluorescence which is typically orders of magnitude stronger than the actual Raman signal. Fluorescence can, in principle, be avoided by measuring anti-Stokes Raman spectra instead of Stokes Raman spectra. However, the intensity of anti-Stokes Raman spectra is typically too low. Textile fibers are often colored using a mixture of dyes. Due to the limitations described above, however, Raman spectroscopy can often only identify the dye with the highest concentration or the one resulting in the strongest Raman scattering peaks. Changing the wavelength of the Raman laser can sometimes help in identifying a secondary dye. Given that there exist thousands of dyes, however, the ability to identify only one or two dyes within a dye mixture can severely limit the usefulness of Raman spectroscopy for forensic purposes. The goal of this project is to evaluate integrating-cavity-enhanced Raman spectroscopy (ICERS) to measure anti-Stokes Raman spectra for the characterization of dyed fibers. ICERS has been developed for the ultrasensitive identification and characterization of materials, and enhancements of five orders of magnitude have been demonstrated. Using ICERS to measure anti-Stokes Raman spectra eliminates the fluorescence background, while the cavity design amplifies the anti-Stokes Raman signal. The combination of the two makes it possible to detect, identify, and characterize minor dye components without interference from fluorescence. Such an approach is expected to reveal more minor dye components which could help narrow down the source of the fiber in question.

The textile industry has grown over the last century and new problems are starting to appear. The disposal of textile waste such as waste dye bath has been the main concern over the years, however, pollution by microplastics in aquatic systems has raised concerns. Microplastics reach to aquatic eco-systems via wastewaters from textiles washing during production or by consumers. Synthetic fabrics are known to create more microplastics problems compared to natural fabrics, like cotton or wool. However, the use of colorants and finishing on cotton can be an important source of organic pollutants in our environment. In cotton, the finishing usually will be added after the dyeing process. The understanding of how these two systems interact together in the bio-degradation in aquatic systems can give us a better idea of possible degradation products and their impact on the environment. For this reason, the analysis and characterization of aqueous systems and their degraded fabrics are needed for a better comprehension of the biodegradation process in an aquatic environment. We propose the characterization of degraded cotton fabrics containing reactive dyes and finishes by analytical methods such as High-Performance Liquid Chromatography (HPLC) and mass spectrometry (MS). For this project, dyed and finished cotton fabrics after bio-degradation received from Professor Richard Venditti from NC State will be studied by extractive methods developed in our laboratories. State-of-the-art analytical instruments such as the quadrupole time-of-flight (QTOF) and the linear quadrupole ion trap (LTQ) mass spectrometers will be used to obtain molecular-level information of the degraded products or combination of degraded products of the reactive dye-finishing system

Garments are items used in our daily life. Color is one of the most important features of a garment. These colors are generated from dyes that are fiber specific. A key aspect of dyed fabric is it??????????????????s washing fastness properties, which is the ability of the dye to maintain its color without washing away during a common laundry cycle. The current work aims to develop analytical methodologies via high-resolution mass spectrometry and cheminformatics, that can enable the identification of unknown dyes leaching from common clothing to the water during laundry, which can stain other pieces of clothing during washing. The results of this study can be very helpful for textile manufacturers and detergent development.

Nonwovens Research - Marked as Confidential

Nowadays, it is required that fabrics have different finishes for multiple purposes (e.g., stain repellant), making our life more comfortable and easier. However, finishes like durable press resin, softeners, stain repellants and their degraded products can be an important source of organic pollutants in our environment. It is expected that the majority of clothing, footwear, linens and other textiles will be dumped in landfills. For this reason, a better comprehension of the decomposition of textiles finishes in soil is needed. We propose a fundamental study of the degradation pathways in soil of different finishes in cotton fabrics, like softeners, flame-retardants, stain repellents and durable press resins, by using different analytical techniques, which include high-resolution mass spectrometry, liquid chromatography, FT-IR, and Raman spectroscopy. In addition, this study will require the development of new analytical methodologies for the extraction of organic compounds from the fabric and soil to recover the chemical compounds that are leaching into the soil and characterize any possible degraded products generated from the finishes mentioned above.

Nowadays, it is required that fabrics have different finishes for multiple purposes (e.g., stain repellant), making our life more comfortable and easier. However, finishes like durable press resin, softeners, stain repellants and their degraded products can be an important source of organic pollutants in our environment. It is expected that the majority of clothing, footwear, linens and other textiles will be dumped in landfills. For this reason, a better comprehension of the decomposition of textiles finishes in soil is needed. We propose a fundamental study of the degradation pathways in soil of different finishes in cotton fabrics, like softeners, flame-retardants, stain repellents and durable press resins, by using different analytical techniques, which include high-resolution mass spectrometry, liquid chromatography, FT-IR, and Raman spectroscopy. In addition, this study will require the development of new analytical methodologies for the extraction of organic compounds from the fabric and soil to recover the chemical compounds that are leaching into the soil and characterize any possible degraded products generated from the finishes mentioned above.

Chemical dyes are central to coloring synthetic fabrics in various textile and manufacturing products. However, certain dyes have shown to induce detrimental toxic effects to exposed individuals, such as allergic contact dermatitis. Building upon our initial cheminformatics analysis of the Max Weaver Dye Library containing more than 98,000 vials of custom-made and largely sparingly water-soluble dyes, we propose to (i) characterize via modern microfluidics and mass spectrometry (MS) techniques a select subset of disperse dyes that are present in household synthetic fabrics and also known to produce dermatitis; (ii) virtually screen more than 2,500 diverse dyes from the Max Weaver dye library to identify possible disperse dyes analogs that can cause dermatitis; and (iii) perform in vivo pig skin studies of the potential analogs disperse dyes from the dye library. This project aims to collect preliminary data for a future grant application to the NIEHS.