【作者】 李艳梅；

【导师】 赫奕；

【作者基本信息】 吉林大学 ， 分析化学， 2013， 硕士

【摘要】 色谱作为一种分离技术与方法，经过一个世纪的发展已经成为一种广泛使用的分析方法。其中气相色谱（Gas Chromatography）已经成为一种相当成熟而且应用非常广泛的复杂混合物的分离分析方法。由于气相色谱自身的缺陷，而且分析检测的检出限低，同时又要从复杂基质中萃取、分离和富集符合仪器分析检测的目标物，所以样品的前处理是非常重要的。传统的样品前处理技术消耗大量有害的有机试剂，对环境造成了严重的污染，同时也会对分析工作者造成伤害。最近，Assadi组开发出了一个简单的液相微萃取方法-分散液液微萃取（Dispersive liquid-liquid microextraction，DLLME），DLLME是一种基于均质液液分散（Homogenous liquid-liquid extraction, HLLE）和浊点萃取（Cloud pointextraction, CPE）的三元试剂体系。DLLME具有操作简单、萃取时间短、成本低、富集倍数高和对环境污染小的优点。DLLME已经被广泛地用于萃取各种不同的污染物如：邻苯二甲酸酯类化合物、除草剂、挥发性污染物、金属离子等。本研究工作主要利用分散液液微萃取和气相色谱联用开展牛奶、茶叶和果汁样品的应用研究。研究重点主要在以下几个方面：1.表面活性剂辅助-分散液液微萃取（surfactant-assisted dispersive liquid-liquidmicroextraction, SA-DLLME）与气相色谱联用检测牛奶中四种邻苯二甲酸酯（PEs）类有机污染物。本研究工作考察优化了气相色谱条件，萃取剂和分散剂的类型、萃取剂的体积、分散剂的体积、pH、离子强度、反萃试剂的种类和反萃试剂的体积。在最优化的实验条件下建立了分析方法，并对牛奶中的邻苯二甲酸酯类物质进行了测定。邻苯二甲酸二甲酯（DMP），邻苯二甲酸二乙酯（DEP）,邻苯二甲酸二丁酯（DBP）和邻苯二甲酸二（2-乙基）己酯（DEHP）方法的线性范围为20500μg L^-1，邻苯二甲酸二环己酯（DCHP）的线性范围为50500μg L^-1；相关系数（R²）在0.9955到0.9999之间。方法的检出限（S/N=3）在7.2914.01μg L^-1之间，精密度（RSDs, n=5）为2.46.9%，富集倍数在19.9到25.8之间，回收率为81.5129.3%。该方法减少了环境污染，降低了成本，缩短了萃取时间。2.本工作研究了悬浮有机液滴固化-分散液液微萃取（Dispersive liquid-liquidmicroextraction based on solidification of floating organic droplet, DLLME-SFO）-气相色谱法检测不同种类茶叶中的有机磷农药残留量。本研究对气相色谱条件进行了优化，同时还对DLLME-SFO的萃取条件进行了优化：萃取剂和分散剂的种类、萃取剂和分散剂的用量、盐的用量。在最优的实验条件下，进行一系列实验，考查了该方法的线性、精密度、检出限和富集倍数；甲基对硫磷和倍硫磷方法的线性范围分别在0.060.8和0.040.8μg mL^-1之间；相关系数在0.9890到0.9982之间。方法的检出限（S/N=3）分别为0.051和0.027μg mL^-1，精密度（RSDs, n=5）为1.06.5%，富集倍数在71.5到136.7之间，回收率在64.9%到134.1%之间。3.利用传统的分散液液微萃取-气相色谱法检测果汁中的有机磷农药残留，在优化的实验条件下对果汁进行测定。考察优化了萃取剂和分散剂的类型、萃取剂的体积、分散剂的体积、离子强度，在最优的实验条件，进行一系列实验考查了方法的线性、精密度、检出限和富集倍数；甲拌磷，甲基对硫磷和倍硫磷的方法的线性范围在0.0240.4，0.040.5和0.0240.4μg mL^-1之间；相关系数在0.98110.9962之间。方法的检出限（S/N=3）分别为0.021,0.024和0.018μg mL^-1，精密度（RSDs, n=5）为7.215.7%，富集倍数在143到226之间，回收率在51.8到128.9%之间。更多还原

【Abstract】 As a kind of separation technique and method, chromatography has become awidely used analytical method after a century of development. And GC is a rathermature and widely used technique in the separation and analyses of complex mixture.Gas chromatography usually suffers from its own drawbacks and also low detectionlevel is required. So sample preparation is very important in order to extract, isolateand concentrate the target analytes from these complicated matrices to obtain samplescompatible for instrumental analysis. Traditional preconcentration techniques needlarge amounts of toxic organic solvents, which are environmentally hazardous andcould harm analysts.More recently, a novel LPME technique named dispersive liquid-liquidmicroextraction （DLLME） was proposed by Assadi and Coworkers, it is based onternary component solvent system such as Homogenous liquid-liquid extraction（HLLE） and Cloud point extraction （CPE）. DLLME has the advantages of ease ofoperation, very short extraction time, low cost and high enrichment factors and isenvironmentally friendly. It has been widely applied for the determination of phthalateesters, herbicides, emerging contaminants and metal ions and so on. This paper isfocused on the application of dispersive liquid-liquid microextraction coupled withgas chromatography in the research of milk, teas and fruit juices.1.A novel extraction method termed surfactant-assisted dispersive liquid-liquidmicroextraction （SA-DLLME） prior to gas chromatography-flame ionizationdetection （GC-FID） was developed for extraction and determination of four phthalateesters （PEs） in milk samples. Some parameters that affect the extraction efficiency were investigated and optimized in this developed technique, such as the type andvolume of extraction solvent, the type and concentration of surfactant, the salt addedand pH value. Under the optimal conditions, the linear range of DMP, DEP, DBP andDEHP obtained was in the range of20500μg L^-1, the linear range of DCHP was50500μg L^-1with the correlation coefficients （R²） ranging from0.9955to0.9999, thelimits of detection （LODs） were7.314.0μg L^-1, the relative standard deviations（RSDs）（n=5） varied from2.4%to6.9%, the enrichment factors （EFs） were19.925.8.The recoveries of PEs from milk samples were ranged from81.5%to129.3%. Theproposed method was demonstrated to be simple, low-cost and practical in thedetermination of PEs in milk samples.2. In this present work, a novel dispersive liquid-liquid microextraction based onsolidification of floating organic droplet （DLLME-SFO） method followed by gaschromatography was applied for determination of organophosphorus pesticides （OPPs）in teas. In this proposed method, a serious of important experimental parameters thataffect extraction efficiency were optimized, such as the type and volume of extractionand dispersive solvents, the amount of salt-addition. Under optimized conditions, thelinear range for methyl parathion and fenthion were0.060.8and0.040.8μg mL^-1with the correlation coefficients （R²） ranging from0.9890to0.9982, the limits ofdetection （LODs） were0.051and0.027μg mL^-1, and relative standard deviations（RSDs） fell in the range of1.06.5%, and the enrichment factors （EFs） varied from71.5to136.7. The recoveries of the target analytes were between64.9%and134.1%.3. A traditional dispersive liquid-liquid microextraction combined with gaschromatography was developed for the determination of OPPs in fruit juices. Someimportant environmental parameters were investigated such as the kind and volume ofextraction and dispersive solvents and salt effect. Under optical conditions, the linearranges of phorate, methyl parathion and fenthion were0.0240.4,0.040.5and0.0240.4μg mL^-1with the correlation coefficients varying from0.9811to0.9962, theLODs for phorate, methyl parathion and fenthion were0.021,0.024and0.018μgmL^-1respectively, and the method precision varied from7.2%to15.7%, and high EFswere achieved in the range of143226. The recoveries of the analytes from fruitjuices were in the range of51.8128.9%.更多还原