RESUMEN
An analytical method for the detection and quantification of silver docusate antimicrobial finishing in soil was developed through a combination of the QuEChERS extraction method and tandem mass spectrometry (MS/MS) quantification with isotopically labeled internal standard. First, the calibration system was established in the matrix where QuEChERS extraction removed docusate from soil. The addition of an isotopically labeled internal standard reduces ionization suppression due to instrumental fluctuation and run-to-run deviation. After establishing the calibration system, this quantification method was validated according to a guideline from the U.S. Food and Drug Administration. A series of variables for quantification were validated including coefficient of determination (R2 = 0.989 ± 0.002), percent error (% error = 3 ± 4%), coefficient of variation (% CV = 6 ± 1%), limit of detection (LOD = 8 ± 2 ng mL-1), lower limit of quantification (LLOQ = 27 ± 5 ng mL-1), recovery and matrix effect (matrix effect = 0.944 ± 0.026). Those parameters were obtained from the inter- and intra-day measurements for both calibration and the quality control standards. Later, samples extracted from a simulated landfill degradation of cotton fabrics applied with sliver docusate antimicrobial finishing were measured. It was observed that the concentration measured (51 ± 5 ng mL-1 or 252 ± 25 ng g-1) fell into the ranges defined by the method development with good precision (% CV = 4 ± 1%). Results from this study could further the understanding of textile landfill degradation and facilitate further study regarding docusate contamination in soil.
Asunto(s)
Antiinfecciosos , Espectrometría de Masas en Tándem , Estados Unidos , Espectrometría de Masas en Tándem/métodos , Cromatografía Líquida de Alta Presión/métodos , Ácido Dioctil Sulfosuccínico , Instalaciones de Eliminación de Residuos , SueloRESUMEN
The presence and biodegradability of textile microfibers shed during laundering or use is an important environmental issue. In this research, the influence of common textile finishes on the persistence of cotton fibers in an aerobic aquatic environment was assessed. The biodegradation of cotton knitted fabrics with different finishes, silicone softener, durable press, water repellent, and a blue reactive dye was evaluated. The rate of biodegradation decreased with durable press and water repellant finishing treatments. In terms of the final extent of biodegradation, there was no significant difference between the samples. All samples reached more than 60% biodegradation in 102 days. The biodegradation rates were in agreement with observed trends of the same samples for cellulase mediated hydrolysis and cellulase adsorption experiments, indicating the finishes impact the initial adsorption of enzymes excreted by the microorganisms and the initial rates of biodegradation, however despite this the cellulosic material maintains its biodegradability.
Asunto(s)
Lavandería , Adsorción , Vestuario , Colorantes , Fibra de Algodón , Poliésteres , TextilesRESUMEN
The influence of common textile finishes on cotton fabrics on the generation of microfibers during laundering was assessed. Microfiber release was determined to be in the range of 9000-14,000 particles per gram of cotton fabric. Cotton knitted fabrics treated with softener and durable press generate more microfibers (1.30-1.63 mg/g fabric) during laundering by mass and number than untreated fabric (0.73 mg/g fabric). The fabrics treated with softener generated the longest average microfiber length (0.86 mm), whereas durable press and water repellent treatments produced the shortest average microfiber length (0.62 and 0.63 mm, respectively). In general, the changes in the mechanical properties of the fibers and fabrics due to the finishing treatments are the main factor affecting the microfiber release. The abrasion resistance of the fabrics decreases for durable press treatments and water repellent treatments due to the brittleness in the structure originated by the crosslinking treatment. In the case of the softener treatment, the fabric surface is soft and smooth decreasing the friction coefficient between fibers favoring the fibers loosening from the textile and resulting in a high tendency for fuzz formation and microfiber release. These findings are useful for the textile industry in the design and selection of materials and treatments for the reduction of synthetic or natural microfiber shedding from textiles.
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Lavandería , Colorantes , Fenómenos Físicos , Poliésteres , TextilesRESUMEN
The aerobic biodegradation of common textiles that shed microfibers during laundering was evaluated under the action of microbes found in the environment, such as lake and seawater, and activated sludge at a low concentration from a wastewater treatment plant (WWTP). Under these conditions, the biodegradation potential was the same in all the experiments: Microcrystalline Cellulose (MCC) > Cotton > Rayon > Polyester/Cotton â« Polyester. Nevertheless, for cotton and rayon yarns, >70% biodegradation was achieved with activated sludge at low concentration and lake water, whereas in seawater, about 50% degradation was reached. Polyester did not appreciably degrade. The biodegradation results herein indicate potential not absolutes in nature. The bacterial diversity analyses in the different biodegradation inoculums show that there are distinct bacterial communities related to the assimilation and mineralization of complex carbohydrates that were promoted with the cellulosic MCC, cotton, and rayon samples different than the polyester sample.
Asunto(s)
Lavandería , Microbiota , Textiles , Contaminantes del Agua/análisis , Biodegradación Ambiental , Celulosa , Vestuario , PoliésteresRESUMEN
The effect of fiber type (cotton, polyester, and rayon), temperature, and use of detergent on the number of microfibers released during laundering of knitted fabrics were studied during accelerated laboratory washing (Launder-Ometer) and home laundering experiments. Polyester and cellulose-based fabrics all shed significant amounts of microfibers and shedding levels were increased with higher water temperature and detergent use. Cellulose-based fabrics released more microfibers (0.2-4 mg/g fabric) during accelerated laundering than polyester (0.1-1 mg/g fabric). Using well-controlled aquatic biodegradation experiments it was shown that cotton and rayon microfibers are expected to degrade in natural aquatic aerobic environments whereas polyester microfibers are expected to persist in the environment for long periods of time.