Browsing by Subject "High performance liquid chromatography."
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item Determination of pharmaceuticals and personal care products in fish using high performance liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry.(Washington, DC : American Chemical Society Publications., 2007) Ramirez, Alejandro Javier.; Chambliss, C. Kevin.; Brooks, Bryan W.; Chemistry and Biochemistry.; Baylor University. Dept. of Chemistry and Biochemistry.Labeled as emerging organic contaminants, pharmaceuticals and personal care products (PPCPs) have been the focus of global environmental research for over a decade. PPCPs have caused widespread concern due to their extensive use. As PPCPs were designed to correct, enhance, or protect a specific physiological or endocrine condition, their target effects in humans and/or farm stocks are relatively well understood and documented. However, there is limited knowledge about their unintended effects in the environment. To address the occurrence, distribution and fate of PPCPs in the environment, efficient and reliable analytical methods are needed. The relatively low concentration, high polarity, and thermal lability of some PPCPs, together with their interaction with complex environmental matrices, makes their analysis challenging. Sample preparation followed by GC or HPLC separation and mass spectrometry (MS) detection has become the standard approach for evaluating PPCPs in environmental samples. PPCPs have been widely reported in water, sediment and biosolids, but reports of their occurrence in aquatic organisms have been limited by the difficulty of analysis. Herein, we report the first HPLC-MS/MS screening method for the analysis of 23 pharmaceuticals and 2 metabolites representing multiple therapeutic classes in fish tissues. The developed methodology was successfully applied to assess the occurrence of target analytes in fish collected from 8 locations throughout the United States (6 effluent-dominated rivers and two reference sites). A complementary GC-MS method was developed for the analysis of 12 additional compounds belonging to either personal care product or industrial use compound classes in fish muscle. This approach was also applied to screen for target analytes in fish collected from a regional effluent-dominated stream.Item Determination of pharmaceuticals in fish and wastewater using isotope dilution high performance liquid chromatography-tandem mass spectrometry.(2009-07-01T16:58:11Z) Hurtado, Pilar Perez.; Chambliss, C. Kevin.; Chemistry and Biochemistry.; Baylor University. Dept. of Chemistry and Biochemistry.A method has been developed for the trace analysis of 15 pharmaceuticals and employs liquid chromatography/tandem mass spectrometry (LC-ESI-MS/MS). Unlike many previous methods, which suffer from matrix suppression and recovery loss, the present method utilizes isotope dilution for each compound to correct for these phenomena. Matrix spike recoveries for all compounds were between 87 and 113% for wastewater effluent, 98 and 144% for fish fillet tissue, and 81% and 105% for fish liver tissue. Method Detection limits (MDLs) in wastewater, fish fillet, and liver tissue were ≤21, ≤13, and ≤41 ng/g, respectively for most analytes. Additionally, this method was directly compared with matrix matched calibration to evaluate potential to compensate for matrix effects. Matrix matched was not suitable to account for matrix effects in samples with highly loaded matrix such as fish liver, though this method offered greater sensitive compared to isotope dilution in the detection of some compounds such as norfluoxetine, sertraline, and fluoxetine.Item High-performance liquid chromatographic methods for quantitative assessment of degradation products and extractives in pretreated lignocellulose.(Amsterdam : Elsevier B. V., 2006) Chen, Shou-Feng.; Chambliss, C. Kevin.; Chemistry and Biochemistry.; Baylor University. Dept. of Chemistry and Biochemistry.Long-term economic, national security, and environmental concerns have motivated research into renewable fuels from lignocellulosic biomass. Among energy alternatives, biomass-derived ethanol represents one of the more promising commodities for long-term sustainability of transportation fuels. Herbaceous agricultural residues, such as corn stover, represent a major source of lignocellulosic material with considerable potential for use in biomass-to-ethanol schemes. Currently, the technology for conversion of biomass to ethanol involves dilute acid pretreatment of lignocellulosic materials, followed by enzymatic hydrolysis of cellulose and fermentation of monomeric sugars to produce ethanol. However, a variety of degradation products are produced upon dilute acid pretreatment of lignocellulosic biomass, which exert an inhibitory effect on downstream fermentation processes and reduce bioethanol conversion. Thus there is increased the demand for reliable analytical methods to advance a more understanding of lignocellulose pretreatment. Several liquid chromatographic methods are developed for a systematic analysis of various degradation products. High-performance liquid chromatography is the most widely used analytical separation technique, because of its reproducibility, sensitivity, and suitability for separating nonvolatile species, which makes the method ready for accurate quantitative determinations. A reversed-phase HPLC method with UV detection is developed for simultaneous separation and quantitation of organic acids and neutral degradation products present in the corn stover hydrolysate. On the other hand, inorganic ions and some organic anions which present in water extractive from corn stover are separated and quantitated by the developed ion chromatographic method with conductivity mode. Sugars and alditols are determined using high-performance anion chromatography with pulsed amperometric detection.