| A complete analysis procedure usually includes sample collection, sample pretreatment, detection and analysis, data processing and results reports. Statistical results show that the time of sample pretreatment required to take up more than 60% of the whole analysis time. The aim of sample pretreatment is to eliminate the interference of other matrix and concentrate or dilute or transfer the form of target analytes to meet the needs of the selected analysis method, so that the analysis test could be going on smoothly and ensure accuracy and reliability of the analysis results. So effective and reasonable sample pretreatment shoud be done prior to most of chemical analysis testing. Sample pretreatments, however, usually require multiple complex operations, including extraction, purification, concentration and re-solvent, lead to the loss of the target analytes and low recovery. What’s worse, some pretreatments need a large amount of solvents consumption and pose a threat to the experimenter and environment. Derivatization technology makes the analytes specifically react with certain derivatization reagents to change analytes’ original chemical structure, in order to achieve the request of the separation and detection. In high performance liquid chromatography-fluorescence detection(HPLC-FLD) analysis works, some of the target analytes have no chromophores or weak fluorescence intensity, which could not be using the high sensitive fluorescence detection mehod. By being reacted with the fluorescent derivatization reagent and getting derivative products with the high activity of fluorescent. After separation highly effective HPLC-FLD, the quantitative determination of target analytes in the sample could be realized. In liquid chromatography- tandem mass spectrum(LC-MS/MS) analysis works, because of the influence of matrix effects and ion suppression, results often show low sensitivity and accuracy. By being reacted with stable isotope derivatization reagents and using isotope internal standard strategy, the target analytes in samples was separated by HPLC and deteced by MS/MS and multiple reaction monitoring(MRM) pattern. Through the signal intensity ratio of "light" and "heavy" derivatization derivatives, we can achieve the relative and absolute quantitative determination of target analytes in samples.Recenty, derivatization combinated with extraction technology as a new type of strategy is widely used in sample pretreatment. This technology organically combinated derivatization technology with many kinds of extraction methods, not only can overcome the complex steps of the pretreatment processes and simplify the process of sample pretreatment, but also overcome the limitations of analytes easy lossing and effectively remove the interference of sample matrixes. Results show that the selectivity, sensitivity, accuracy and recovery of the method could be effectively improved.Therefore, the aims of this paper is to develop the novel sample pretreatment techniques, which derivatization strategy and extraction technology could be organically combined, a novel types of stable isotope derivatization reagents are designed and synthesized and applied to LC-MS/MS analysis. The specific work contents are as follows:Chapter one: The progress of sample pretreatment techniques in the application of HPLC-MS/MS analysis were reviewed, including sample extraction, purification and preconcentration technology(liquid phase extraction, solid phase extraction and microextraction technique), derivatization technology(pre-column fluorescent derivatization and stable isotope derivatization technology) and derivatization combined with extraction strategy.Chapter two: In view of the complexed and low efficient sample pretreatment operation, a novel sample pretreatment technique, ultrasonic-assisted derivatization microextraction(UDME) prior to HPLC-FLD-MS/MS has been developed. Derivatizition and sample microextraction are simultaneously processed and ultrasound-assisted procedure accelerated the solvent extraction and derivatization, making the operation more simple and rapid. Compared with traditional methods, this technique reduce the loss of the target analytes, thus the recovery is higher and the results are more accurate than before. This method is applied for sensitive, accurate and rapid determination of the trace trace levels of 12 kinds of fatty amines in the environmental soil and water samples.Chapter three: For some unstable and easily oxidative target analytes like resin acids, a novel sample pretreatment technique, ultrasonic-assisted closed in-syringe extraction and derivatization(UCSED) prior to HPLC-FLD-MS/MS has been developed. The whole process of pretreatment technology including extraction and derivatization procedure achieved in a closed syringe with mild conditions and ultrasound-assisted procedure accelerated the solvent extraction and derivatization. This method is applied for quick, efficient and accurate quantitative determination of two kinds of resin acids(abietic acid and dehydroabietic acid) in the cosmetic samples and this method has showed obvious superiority for the analysis of unstable and easily oxidative target analytes.Chapter four: A novel sample pretreatment technique, ultrasonic-assisted dispersive liquid-liquid microextraction-stable isotope derivatization(UADLLME-SID) prior to HPLC-MS/MS has been developed. This technology organically combines the sample extraction and preconcentration operation(UADLLME) with derivatization procedure(SID). Ultrasound-assisted procedure accelerated the solvent extraction and derivatization and the efficiency of the pretreatment could be dramatically improved. The isotope-labeled internal standard strategy could overcome the matrix effects and ion suppression. In addition, According to the paucity of stable isotope derivatization reagents, the complexity of synthesis procedure, low stable isotopes utilization rate of raw materials, reagents costly, difficult to widely used. Apair of novel stable isotope derivatization reagents were simplely designed and synthesized by the indole-3-acetic acid as raw materials: d0-/d3-MIAA. Application of this technology for quantitative determination of UV filters in environmental water samples, and the accuracy, sensitivity and recovery of the methd are dramatically improved. |
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