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Study on Sample Pretreatment and Determination of Enviromental Endocrine Disruptors

Author: LuZuo
Tutor: WangZhiHua
School: Beijing University of Chemical Technology
Course: Chemistry
Keywords: monolithic silica spin column phthalate esters estrogen physiological saline milk high performance liquid chromatography-mass spectrometry (HPLC-MS)
CLC: X830.2
Type: Master's thesis
Year: 2011
Downloads: 39
Quote: 0
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Abstract


Since Enviromental endocrine disruptors have ultra high physiology activity at very low concentration, they have become a threat to eco-environment and human health. Therefore, enviromental endocrine disruptors have aroused the attention of the world and become a new global environmental problem. Phthalates and estrogens are two prominent members of the group of envirmental endocrine disruptors.Because of high resolution and sensitivity, liquid chromatography-mass spectrometry (LC-MS) has widely applied in environment, medical analysis, clinic detection and life science. Though LC-MS has powerful analytical ability, when it is applied for real sample analysis, complex matrices often seriously interfere the final results. In this case, to develop simple, rapid and effective pretreatment method is an important impetus to broaden the application of LC-MS technology. The aim of this thesis is to develop rapid and effective pretreatment method coupled with LC-MS for quantitative analysis of phthalates and estrogens in various matrices.The main study is giving as follows:1. Six phthalates including dimethyl-(DMP), diethyl-(DEP), dipropyl-[DPrP], butyl-benzyl-(BBP), dicyclohexyl-(DcHP), and di-n-octyl-(DOP) phthalate in physiological saline samples were identified and quantified by monolithic silica spin column extraction followed by high performance liquid chromatography-mass spectrometry (LC-MS) method. C18 bonded monolithic silica spin column was employed in the work. C18 cartridge was used for enrichment of all target phthalates from the polar impurities. Besides, this method was linear in the following ranges:0.2～50μg/L for DMP, DEP, DPrP, DcHP and DOP, 5～100μg/L for BBP. The correlation coefficients (r2) were in the range of 0.9951～0.9995 for all the analytes and the limits of detection (LODs) and limits of quantification (LOQs) were in the ranges of 0.02～0.9μg/L and 0.08～2.7μg/L, respectively. The pretreatment process showed good reproducibility with inter-day and intra-day relative standard deviations (RSDs) below 8.5% and 11.2%, respectively. In the optimized condition, this method was used to verify the presence of the target analytes in physiological saline samples. Some estrogens were detected in the physiological saline samples in plastic package. The achieved results demonstrated that a lot of concern should be addressed about the potential risk of the present of phthalates in physiological saline. 2. Octadecyl (C18) bonded monolithic silica material was applied as solid-phase extraction (SPE) sorbent and a SPE-LC-MS method was established for the determination of 5 estrogens in milk samples. Compared to commercial C18 SPE cartridge, the performance of C18 bonded monolithic silica material was evaluated in various important SPE conditions, such as elution solvent and its volume, loading flow rate. The results showed superior performance of C18 bonded monolithic silica material to nomal C18 by the fewer required elution solvent and higher extraction efficiency. In the optimum conditions, the results showed good recoveries (72.6%-94.3%), excellent linear relationships (0.1-50μg/L, except E3 and EE2), high precisions (lower than 13.0% RSD for both low and high spiked concentration) and low limits of detection (0.02-0.10μg/L). Method validation using C18 bonded monolithic silica packed cartridge was also testified with spiked real milk samples and fat free milk samples. Satisfied results demonstrated the feasibility of C18 bonded monolithic silica SPE to the analysis for real milk samples.

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CLC: > Environmental science, safety science > Environmental Quality Assessment and Environmental Monitoring > Environmental monitoring > General issues > Monitoring and analysis methods
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