基质固相分散-高效液相色谱法测定食物中痕量异丙威和溴氰菊酯

本文研究了应用基质固相分散(MSPD)处理复杂样品技术与高效液相色谱法相结合测定食物中痕量异丙威和溴氰菊酯残留物的新方法。介绍了MSPD技术进行前处理的实验条件并讨论了与传统残留分析的区别。本文将MSPD技术用于水果、粮食等食物中异丙威和溴氰菊酯残留物的高效液相色谱分析,并对定量检测条件作了详细的研究。     

液上气相色谱法在酱油分析上的应用

一、液上气相色谱基本理论液上气相色谱分析,是将液上气体分析与气相色谱分析联用的一种科学分析技术。液上气体分析是指封闭系统中与液体(或固体)样品相平衡之气体的分析。液上气相色谱法是指用气相色谱法来分析封闭系统中与液体(或固体)样品相平衡之气体的方法。它是通过对液体(或固体)样品中挥发性成分的蒸气相的气相色谱检测。达到对样品成分定性和定量的目的。     

基质固相分散-气相色谱法同时测定蔬菜水果中多种农药残留

建立了一个简单、快速的多种类型农药残留同时分析的新方法。采用一种新的样品前处理方法-基质固相分散(Matrix Solid-Phase Disperse，MSPD)替代传统的液-液萃取、固相萃取，从蔬菜水果中提取、净化三种类型31种常用农药残留(包括11种有机氯、5种拟除虫菊酯、15种有机磷)，用GC-ECD和GC-FPD分析检测，用GC-MS(SIM)进行确证。31种农药的回收率在80．4％～112．7％之间，相对标准偏差小于10％。实验表明本方法适用于各种新鲜蔬菜水果样品的农药残留分析。     

基于色差及电子鼻的红糖品质研究

以红糖作为研究对象,对比不同产地及榨季红糖固体及其在相同浓度溶解时液体的色差,以及分析红糖固体样品特征气味成分并探讨色差计及电子鼻测定红糖风味品质的可行性。实验结果表明：不同产地及榨季的红糖样品的色泽具有明显差异,且不同产地的红糖样品挥发性成分也有差异。电子鼻可以有效识别判定不同产地的红糖并测定其特征气体成分,即硫化物及氮氧化物。色差计和电子鼻皆可以作为代替感官评价对红糖风味品质进行测定及评价的技术手段。     

固体进样等离子体光谱技术在食品元素分析中的应用

固体进样等离子体光谱技术兼具固体进样无需消解、进样效率高、简单、快速、环保以及等离子体光谱动态线性范围宽、灵敏度高、多元素分析的优势,在食品元素分析中具有良好的应用前景。本文综述了固体进样等离子体光谱技术用于食品元素分析的样品制备、样品导入及分析仪器的研究现状,重点对直接固体进样和悬浮液进样方式,电热蒸发、样品直接插入、激光烧蚀、激光诱导击穿等样品导入方式,以及样品均匀性、基体干扰与标准曲线等主要问题进行了探讨和展望。     

电子探针分析玻璃表面K~ 离子交换浓度的卷积修正处理

电子探针是分析固体成分及表面浓度分布的现代测试方法。但是,在电子束轰击下,由于分析样品中x射线激发区的重叠、热效应、表面效应及仪器有限的分辨能力等原因,使K~ 一Na~·离子交换表面K~ 的测试浓度和真实浓度之间产生一定误差。为保证测试结果的精确性,有必要对电子探针测试数据加以修正。 分析样品为于470℃、在KNO_3熔盐中浸润三小时的Na_2O—CaO—SiO_1玻璃。经过离子交换后,由样品表面到中心层形成了K~ 浓度梯度,其分布如图中的曲线I。     

微波真空干燥法生产固体蜂蜜

对不同条件下微波真空干燥蜂蜜的干燥速率及样品温度的变化进行了测量和比较，以优化其干燥工艺条件。在优化的干燥条件下得到的固体蜂蜜的颜色基本没有变化，并应用高效液相色谱法测定了蜂蜜干燥前后主要糖成分的变化，应用固相微萃取，气-质联谱对干燥前后蜂蜜中的挥发性风味成分及含量的变化进行了检测和比较。结果显示果糖、葡萄糖、蔗糖和麦芽糖等的含量没有明显变化，说明干燥过程中未发生美拉德反应，其挥发性成分含量有一些变化，但不影响蜂蜜固有的风味。     

基质固相分散-气相色谱法测定胡萝卜中百菌清和拟除虫菊酯类农药

建立了毛细管气相色谱法同时分析胡萝卜中百菌清和5种拟除虫菊酯类农药的方法。样品以乙酸乙酯为洗脱剂经基质固相分散(matrix solid-phase dispersion,MSPD)提取和净化,DB-5毛细管柱分离,采用GC-μECD分析、外标法定量。样品加标回收率为80.5%～107.6%,相对标准偏差小于7%,方法检出限为0.003～0.006mg/kg。该方法简便、快速、灵敏、准确,符合蔬菜中百菌清和拟除虫菊酯类农药检测的要求。     

MSPD和SPE两种方法前处理苹果(汁)中棒曲霉素的比较研究

建立并比较了分别采用基质固相分散(MSPD)和氰基柱固相萃取(SPE)两种前处理技术,高效液相色谱(HPLC)检测苹果(汁)中棒曲霉素的方法.两种方法的回收率和变异系数均满足检测要求.结果表明,建立的两种方法简便、快速、准确,各有优缺点,不同的样品中棒曲霉素的前处理应采用不同的方法.     

热辐气动干燥法快速测定牛奶中总固体和水分

利用圆盘自动进样热辐箱式胶乳样品干燥仪研究快速测定牛奶中总固体和水分含量的方法。分别对加热温度、加热时间及温度平衡时间进行实验,以烘箱法（标准法）为对照,不断优化实验条件,并测定了多份牛奶样品中总固体和水分的含量。结果表明：用本方法和烘箱法测定相同样品中总固体和水分含量的准确度和精确度结果一致,而烘箱法需耗时约3.5 h,本方法只需2.0 min完成,大大提高了分析效率。     

Comparison of matrix solid-phase dispersion and liquid-liquid extraction for the chromatographic determination of fenthion and its metabolites in olives and olive oils

Matrix solid-phase dispersion (MSPD) methodology has been developed to extract fenthion and its metabolites from olives and olive oils, and the technique compared with conventional liquid-liquid extraction (LLE). The method was applied to olives and olive oil samples obtained from olive groves treated with fenthion. Pesticide residues were analysed by gas chromatography (GC) using a nitrogen-phosphorus detector. Both extraction methods gave a linear response over the concentration range assayed (0.03-1 mg kg^-1 for MSPD and 0.1-1 mg kg^-1 for LLE). Recoveries and RSD (n = 6) values in olives were 85-112% and 2-6% for MSPD, and 68-108% and 4-16% for LLE, respectively. In the case of olive oil, recoveries and RSD (n = 6) values were 67-98% and 5-11% for MSPD, and 63-115% and 6-14% for LLE, respectively. When compared to LLE, the newly developed MSPD method was twice as sensitive and required 10 times less sample weight.     

Analysis of patulin in apple products by liquid–liquid extraction,solid phase extraction and matrix solid-phase dispersion methods: a comparative study

Patulin is a marker of quality in the apple and apple juice industry and due to the potential risk for human health, reliable and potential methods for extracting patulin from a sample are therefore needed. In this study, the three methods with liquid–liquid extraction, matrix solid-phase dispersion (MSPD) and with solid-phase extraction (SPE) were studied for extracting patulin from different apple products. Result showed that for AJC and apple sample, MSPD method is most suitable for extracting patulin among the three methods. The recovery rates of AJC and apple sample were 80.35–114.46 and 79.68–94.32%, respectively, the coefficient variations were 3.18–4.90%; For dilute juice, SPE procedure is suitable for analysis of patulin and the recovery rates were and 85.35–90.14%.     

3种固相萃取新技术在食品检测前处理中的应用

固相萃取技术是样品前处理中常用的方法,具有试剂用量少、环境污染少、无乳化、操作简单等优点。本研究介绍了固相微萃取、基质分散固相萃取和在线固相萃取等3种固相萃取新技术在食品检测领域中的应用,并对各技术的优缺点进行了分析,同时阐述了各技术在食品检测领域的发展局限性及发展趋势,以期为这3种技术的应用提供参考依据。     

基质固相分散-气相色谱法测定蔬菜中的甲胺磷

建立了弗罗里硅土-石墨化炭黑的基质固相分散样品前处理法,并将该方法用于不同蔬菜中甲胺磷的残留分析,GC-NPD分析检测。对固相分散剂、样品与分散剂用量比例、洗脱溶剂及用量进行了选择和优化。结果表明,五种蔬菜中甲胺磷的回收率在85.7%～109.2%之间,相对标准偏差小于8%,可见本法可以用于各种新鲜蔬菜样品中甲胺磷的残留分析。     

食品中氯丙醇测定方法研究进展

本文综述了食品中氯丙醇检测的方法,主要介绍了基质固相分散萃取法(MSPD)、固相微萃取法(SPME)、液-液萃取法在食品样品氯丙醇提取、净化上的应用;对目前用于氯丙醇衍生化的试剂七氟丁酰类(HFBI、HFBA)、硼酸类(丁基硼酸、苯基硼酸)、丙酮或庚酮、三氟乙酸酐(TFAA)、N,O-双三甲基-三氟乙酰胺(BSTFA)的适用性作了评述,重点地介绍了HFBI的应用;从氯丙醇及其衍生物分析的内标选择、色谱柱、分离条件、检测等方面对作了简要评价;最后介绍了3-MCPD的快速筛选方法。     

Development of a matrix solid-phase dispersion-sonication extraction method for the determination of fungicides residues in ginseng extract

A rapid method based on matrix solid-phase dispersion (MSPD) was developed for the determination of pentachloronitrobenzene, pentachloroaniline, methylpentachloro-phenylsulphide and procymidone in ginseng extract using gas chromatography. The optimal conditions selected for MSPD extraction were as follows: after blending 5 mL of aqueous ginseng extract (10%, w/v) with Florisil (10 g), the mixture was passed into a small chromatographic column and extracted twice with 10 mL ethyl acetate–hexane solvent mixture (70:30, v/v) for 15 min in an ultrasonic bath at room temperature. The analytical performance of this method showed MSPD to be efficient, fast, simple and had little or no matrix effect. The method detection limits varied from 0.1 to 0.4 μg/L. Mean recoveries were found in the range of 83.5–97.4% and had a good linear relationship (r² ? 0.9987) with relative standard deviations less than 10%. The proposed method has proved to be a feasible one for the analysis of fungicide residues in ginseng extract.     

Development and Validation of a Matrix Solid-Phase Dispersion Method to Determine Acrylamide in Coffee and Coffee Substitutes

ABSTRACT: The present study describes the development and validation of a new method based on a matrix solid-phase dispersion (MSPD) sample preparation procedure followed by GC-MS for determination of acrylamide levels in coffee (ground coffee and brewed coffee) and coffee substitute samples. Samples were dispersed in C₁₈ sorbent and the mixture was further packed into a preconditioned custom-made ISOLUTE bilayered SPE column (C₁₈/Multimode; 1 g + 1 g). Acrylamide was subsequently eluted with water, and then derivatized with bromine and quantified by GC-MS in SIM mode. The MSPD/GC-MS method presented a LOD of 5 μg/kg and a LOQ of 10 μg/kg. Intra and interday precisions ranged from 2% to 4% and 4% to 10%, respectively. To evaluate the performance of the method, 11 samples of ground and brewed coffee and coffee substitutes were simultaneously analyzed by the developed method and also by a previously validated method based in a liquid-extraction (LE) procedure, and the results were compared showing a high correlation between them.     

基质固相分散—高效液相色谱法测定蜂蜜中三种酚类化合物

采用基质固相分散技术处理样品、反相高效液相色谱法同时测定蜂蜜中三种酚类化合物.Diamonsil C18柱,甲醇-水(体积比为45:55)流动相,检测波长275 nm.在0.04 mg/L～16.3 mg/L范围内3组分线性关系良好.方法检出限分别为0.05 mg/kg～0.06 mg/kg.回收率范围:86.88%～90.88%.相对标准偏差分别为2.25%、2.31%、2.48%.     

Determination of Sulfonylurea Herbicides in Food Crops by Matrix Solid-Phase Dispersion Extraction Coupled with High-Performance Liquid Chromatography

A simple and sensitive method was developed for the determination of four sulfonylurea herbicides (metsulfuron-methyl, chlorsulfuron, chlorotoluron, and bensulfuron-methyl) using matrix solid-phase dispersion (MSPD) extraction followed by high-performance liquid chromatography. The experimental conditions for the MSPD extraction, such as type and amount of dispersant, the ratio of dispersant to sample, type and volume of washing and elution solvent were evaluated and optimized. Under the optimal conditions, the calibration curves for the sulfonylurea herbicides had good linear relationships (r?>?0.997) in the concentration range of 0.2–10 μg g^?1, and the limits of detection were in the range of 0.02–0.07 μg g^?1. The recoveries of the sulfonylurea herbicides at two fortification levels were between 62.0 and 102.6 % with the relative standard deviations less than 6.92 %. The methodology was successfully applied to the analysis of four sulfonylurea herbicides in food crops.