【作者】 屈春花；

【导师】 罗红群；

【作者基本信息】 西南大学 ， 分析化学， 2011， 硕士

【摘要】 样品前处理技术(Sample pretreatment technology)是指样品的制备和对样品采用合适的分解和溶解方法以及对待测组分进行提取、净化和浓缩的过程,使被测组分转变成可测定的形式,从而进行定量、定性分析。样品前处理的目的是消除基体干扰,提高方法的准确度、精密度、选择性和灵敏度。因此,样品前处理是分析检测过程的关键环节,若选择的前处理方法不当,可能会导致某些组分损失、干扰组分的影响不能完全除去或引入新的杂质。然而只要检测仪器稳定可靠,检测结果的重复性和准确性就主要取决于样品前处理。一种新的检测方法的灵敏度和分析速度往往也与样品前处理过程及其复杂程度有着至关重要的联系。高效液相色谱(High performance chromatography, HPLC)法是色谱分析中最常用到的对物质进行定性、定量分析的一种方法,它跟经典液相色谱法相比较,具有分析速度快、分离效能高、选择性高、检测灵敏度高和操作自动化等特点。因此,高效液相色谱法在医药、生化、天然产物、环境分析、农业分析以及食品安全检验等领域应用非常广泛。本文采用了固相萃取(SPE)、浊点萃取(CPE)和离子液体分散液相微萃取(IL-DLME)等快速有效的样品前处理技术对饲料中的β-兴奋剂以及饮料中的赤藓红进行提纯,并结合高效液相色谱对其进行分离检测。主要研究内容如下：1.固相萃取结合超高效液相色谱法同时测定饲料中的西马特罗、沙丁胺醇、特布他林和莱克多巴胺建立了固相萃取结合超高效液相色谱(UPLC)同时测定饲料中的西马特罗、沙丁胺醇、特布他林和莱可多巴胺的方法。饲料混合均匀后,用甲醇提取,振荡离心,取上清液氮气吹干后用于MCX柱净化。四种β-兴奋剂的线性范围为0.05-1μg mL-1,相关系数都高于0.999。平均回收率在90.1%到101.4%之间,相对标准偏差小于8.0%。2.固相萃取结合超高效液相色谱法同时测定饲料中五种β-兴奋剂采用固相萃取提纯饲料中的五种β-兴奋剂(盐酸多巴胺、西马特罗、沙丁胺醇、特布他林和莱克多巴胺),并通过超高效液相色谱(UPLC)对其进行分离测定。饲料混合均匀后,用甲醇提取,振荡离心,取等量上清液两份：一份酸化后直接过酸性氧化铝柱,用1 mol L-1盐酸-甲醇(1/9,v/v)洗脱；另一份氮气吹干后用2%乙酸水溶液溶解后过MCX柱,5%氨化甲醇洗脱。合并两种洗脱液,40℃下氮气吹干,加1.0 mL浓度为10 mM的磷酸二氢钠溶液溶解,过0.22μm滤膜后测定。五种p-兴奋剂的线性范围为0.05-1μg ml-1,相关系数都高于0.996。平均回收率在77.9%到97.0%之间,相对标准偏差小于4.3%。3.浊点萃取结合高效液相色谱测定饮料中的赤藓红用非离子表面活性剂Triton X-114对饮料中的赤藓红进行萃取,然后用紫外检测器结合高效液相色谱进行检测,建立了一种检测饮料中赤藓红的新分析方法。分别取10.0 mL加入了不同浓度标准溶液的饮料进行浊点萃取,富集因子为50。方法的线性范围为0.002-5μg mL-1,相关系数都大于0.999,检出限(LOD)和定量限(LOQ)分别为0.5 ng mL-1和1.5 ng mL-1.平均回收率在86.5%到97.1%之间,相对标准偏差小于5.7%。4.离子液体分散液相微萃取结合高效液相色谱测定饮料中的赤藓红离子液体分散液相微萃取(IL-DLME)结合高效液相色谱第一次运用于测定饮料中的赤藓红。这种技术选择了不易挥发的有机溶剂离子液体作为萃取溶剂,集萃取与浓缩于一体。本文采用的离子液体是1-辛基-3-甲基咪唑六氟磷酸盐([C8MIM][PF6]),并对离子液体的用量、甲醇的体积、工作溶液的pH值、萃取时间和溶解温度进行了优化。方法的线性范围为0.005-5μg mL-1,相关系数都大于0.999,检出限(LOD)和定量限(LOQ)分别为2.0 ng mL-1和6.0 ng mL-1。平均回收率在83.6%到95.6%之间,相对标准偏差小于8.4%。这种方法具有操作简单、快速、成本低、回收率和富集因子高等优点。更多还原

【Abstract】 Sample pretreatment technology refers to the sample preparation and sample decomposition and dissolution using appropriate methods and the process of treatment of test components through extracted, purified and concentrated, so that the determined analytes can be transformed into the form to be quantitative and qualitative analysis and detection. Sample pretreatment is designed to eliminate the matrix interference, improve accuracy, precision, selectivity and sensitivity of the method. Therefore, sample pretreatment is the key to the process of analysis and detection. If you choose the improper pretreatment methods, it may often lead to loss of certain components, the impact of disturbance component can not be completely removed or introduced new impurities. But as long as the detection instruments are stable and reliable, reproducibility and accuracy of test results mainly depends on the sample preparation. Sensitivity of a new kinds of detection method and its analysis speed also have an important relationship with the sample pretreatment process and the complexity of sample pretreatment.High performance liquid chromatography (HPLC) method is the most commonly used chromatographic method for qualitative and quantitative analysis of substances. Compared with the classical liquid chromatography, HPLC has the characteristics with high analysis speed, high separation efficiency, high selectivity, high sensitivity and operation of automation and so on. Therefore, high performance liquid chromatography is widely used in the fields of medicine, biochemistry, natural products, environmental analysis, agricultural analysis and food safety inspection.In this paper, several fast and efficient sample pretreatment techniques such as solid phase extraction, cloud point extraction and ionic liquid dispersive liquid-phase microextraction are used for purification ofβ-agonists in feed and erythrosine in beverages, combined with HPLC for separation and detection.The main contents are as follows:1. Simultaneous determination of cimaterol, salbutamol, terbutaline, and ractopamine in feed by solid phase extraction coupled to ultra performance liquid chromatographyAn ultra performance liquid chromatography (UPLC) method was established for the simultaneous determination of cimaterol, salbutamol, terbutaline, and ractopamine in feed. Target compounds were extracted with methanol and centrifuged. The supernatant was then transferred and concentrated, and applied to a solid phase extraction MCX cartridge for clean-up before UPLC analysis. The calibration curves for the four beta-agonists were good linear in concentration range of 0.05-1μg mL-’with the correlation coefficients (r) over 0.999. The average recoveries were in the range of 90.1 to 101.4% with relative standard deviation values lower than 8.0%.2. Simultaneous determination of fiveβ-agonists in feed by solid phase extraction coupled to ultra performance liquid chromatographyAn ultra performance liquid chromatography (UPLC) method was established for the simultaneous determination of dopamine, cimaterol, salbutamol, terbutaline, and ractopamine in feed. Target compounds were extracted with methanol and centrifuged. Two equal supernatants were taken:one was applied to a solid phase extraction Alumina A cartridge after acidified and the other was applied to a MCX cartridge when it was concentrated and dissolved in 2% acetic acid. The former was eluted with 1 mol L-1 hydrochloric acid-methanol (1/9, v/v) and the later was eluted with 5%(v/v) ammonia hydroxide in methanol. The elutes were combined and then evaporated to dryness under a stream of nitrogen at 40℃and dissolved in 1.0 mL of sodium dihydrogen phosphate (10 mM, pH 2.7) for UPLC analysis after being filtered through a 0.22μm membrane. The calibration curves for the five beta-agonists were good linear in concentration range of 0.05-1μg mL-1 with the correlation coefficients (r) over 0.996. The average recoveries were in the range of 77.9 to 99.7% with relative standard deviation values lower than4.3%.3. Cloud point preconcentration to the determination of erythrosine in soft drinks by high-performance liquid chromatography with UV detectionA new analytical method for the determination of erythrosine in soft drinks was developed using the cloud point extraction of non-ionic surfactant (Triton X-114) prior to high-performance liquid chromatography with ultraviolet detection (HPLC-UV) analysis. The comound was extracted from 10.0 mL of different soft drinks and a preconcentration factor of 50 was obtained. The proposed method showed good linear relationship in the concentration range of 0.002-5μg mL-with the correlation coefficient over 0.999. The limit of detection (LOD) and limit of quantification (LOQ) were 0.5 ng mL-1 and 1.5 ng mL-1, respectively. The average recoveries were in the range from 86.5% to 97.1% with relative standard deviation value lower than 5.7%.4. Determination of erythrosine in soft drinks by ionic liquid dispersive liquid-phase microextraction coupled with high-performance liquid chromatographyA new approach for the determination of erythrosine in soft drinks by ionic liquid based dispersive liquid-phase microextraction (IL-DLME) prior to high-performance liquid chromatography with ultraviolet detection (HPLC-UV) was developed. This technique selects the ionic liquid instead of a volatile organic solvent as the extraction solvent, and combines extraction and concentration of the analyte into one step. 1-Octyl-3-methylimidazolium hexafluorophosphate [C8MIM][PF6] was used as the extraction solvent and the factors affecting the extraction efficiency such as the volume of [C8MIM][PF6], amount of methanol, pH of working solutions, extraction time, and dissoluble temperature were optimized. The proposed method showed good linear relationship in the concentration range of 0.005-5μg mL-1 with the correlation coefficient (r) over 0.999. The limit of detection (LOD) and limit of quantification (LOQ) were 2.0 ng mL-1 and 6.0 ng mL-1, respectively. The average recoveries were in the range from 83.6% to 95.6% with relative standard deviation values lower than 8.4%. This method has the advantages of simplicity of operation, rapidity, low cost, high recovery, and enrichment factor.更多还原