Physical Sciences and Mathematics Commons^™

Determination Of Multiple Pesticides Residues In Imported Tea In Uae Using Liquid And Gas Chromatography And Tandem Mass Spectrometry, Sarra Ali Mohammed Hassan Almulla

Theses

An accurate, rapid and reliable method for the simultaneous determination of 48 pesticide residues in United Arab Emirates imported tea (Green and Black) by liquid and gas chromatography coupled with tandem mass spectrometry LC–ESI (+) - MS/MS and GC-EI-MS/MS. Multiple reaction monitoring (MRM) mode was used in which two transitions for each compound for pesticide identification and quantification in the presence of internal standards. Modified quick, easy, cheap, effective, rugged, safe (QuEChERS) method was used for sample clean up and preparation for chromatographic analysis. The performance of the newly developed analytical method was validated in accordance with EU SANCO guidelines …

Continuous Monitoring Of Volatile Organic Compounds In Air Emission Using Membrane Extraction Microtrap Gc System, Xin Zhang

Theses

A novel method for continuous monitoring volatile organic compounds (VOCs) in air at trace level is presented. A membrane module and a microtrap were used along with gas chromatographic analysis. The membrane module consisted of a bundle of silicone rubber hollow fibers and separated the VOCs from the gaseous stream. The microtrap which is a very small adsorbent trap played the roles of preconcentrator and injector. The VOCs selectively permeate across the membrane into a strip gas in the membrane module. Before entering the GC column, the VOCs are trapped and concentrated by the microtrap. Desorption of the VOCs is …

The Use Of Henry's Law Constants In The Determination Of Factors That Influence Voc Concentration In Aqueous And Gaseous Phases In Wastewater Treatment Plant, Hui-Zhi Yu

Theses

This study focuses on the determination and comparison of Henry's law constant of eight selected volatile organic compounds in the wastewater of Linden Roselle Sewerage Authority (LRSA) wastewater treatment plant. The factors that influence the vapor-aqueous equilibrium were studied by calculating the Henry's law constants of the different species determined in the gas phase before and after the spiking of different aqueous media. Both centrifuged and uncentrifuged wastewater samples were studied, and compared to distilled water.

For wastewater sample with no suspended particles, the amount of organics in wastewater appears to influence the Henry's law constant for compounds with low …

Measurement Of The Removal Of Selected Vocs From A Municipal Treatment Plant, Hong Yu

Theses

Industrial wastewater contains a variety of volatile chemical constituents. The large majority of the volatiles are organics. Many of these volatile or¬ganic compounds (VOCs) end up in the effluent to wastewater treatment plants. It is necessary to estimate the emission of the VOCs from sewerage plants in order to study the fate of these volatile organic compounds.

This study focuses on the estimation and comparison of the emission of 28 volatile organic compounds from the water and air in four operation units of Linden Roselle Sewerage Authority (LRSA) wastewater treatment plant. The removal rates of these target compounds have been …

Liquid-Vapor Equilibria And Henry's Law Constants For Volatile Organics In Surfactants, Qianping Peng

Theses

We present liquid vapor equilibria data and Henry's law constants for Methyl-ethyl Ketone, Toluene, Butyl Acetate, Acetone and i-Propanol in surfactants: Octylphenyl Decaethoxylate, Sorbitan Monooleate and Sodium Sulfonate at temperatures of 20 to 70 C.

The objective of this study is to determine the effect of applying surfactant absorption technique (neat surfactants) to volatile organic compounds (VOC's) for the removal of these species as organic vapors from air emission streams.

Liquid/vapor equilibrium data are presented as curves in several different ways:

i. Each individual VOC at four temperatures between 22 C to 70 C in the respective surfactants Octylpenyl Decaethoxylate, …

Degradation Of Refractory Organic Pollutants In Tar, Water And Soil Matrices By Ozone Or Hydrogen Peroxide With Ultraviolet Light, Liang-Jiun Uang

Theses

The objective of this research is to develop a method to degrade refractory Tar materials, higher molecular weight 3-5 ring Poly Aromatic Hydrocarbons (PAH's) or degrading these highly refractory PAH structures so that they are amenable to further treatment by biological or chemical methods. The process utilized to achieve this is to treat contaminated soils or tar materials with hydrogen peroxide or ozone plus ultraviolet light. Analysis of 27 specific PAH's was done by gas chromatograph (Flame Ionization Detection) for the reactants and products. The contaminated soil showed significantly lower levels of these PAH's after treatment.

Organics In Ambient Air By Collection On Tenax, Thermal Desorption,And Capillary Chromatography With Parallel Fid/Ecd Analysis, Chih-Hsiang Liao

Theses

Volatile organics in ambient air were regularly collected on Tenax cartridges at high (10 ml/min) and low (5 ml/min) intake flows. These Tenax samples were analyzed by using a Tekmar Automatic Thermal Desorber and capillary GC system with parallel flame ionization (FID) and electron capture detectors (ECD). A series of quality assurance procedures has been established to improve and assure the accuracy and precision of sample collector and analysis. These procedures relate to performance of the Tekmar thermal desorber, recovery efficiency from the Tenax, and include studies on breakthrough and co-elution. The results demonstrate (1) that from ambient air data …