微波萃取气相色谱-质谱法测定塑料中的增塑剂

建立了利用微波萃取气相色谱-质谱法同时测定塑料中18种增塑剂的方法。该方法以乙酸乙酯为萃取溶剂,采用微波萃取法提取塑料中邻苯二甲酸酯类、己二酸酯类、磷酸酯类、柠檬酸酯类等四种不同类型的18种增塑剂,采用气相色谱-质谱法对萃取液中的增塑剂同时进行测定。对色谱条件和样品前处理条件进行了优化,四种不同类型增塑剂的平均回收率为93.96%~101.20%,精密度实验相对标准偏差为1.09%~5.82%,检测限(S/N=3)为0.3~10mg/L。该方法简便、准确,灵敏度高,可满足塑料中多种类型增塑剂的检测要求。     

学生用塑料书套中邻苯二甲酸酯的快速检测

建立了学生用塑料书套中6种常见邻苯二甲酸酯(PAEs)类增塑剂的快速检测方法。以二氯甲烷为萃取溶剂,通过超声萃取对样品中的PAEs进行提取,随后采用气相色谱-质谱联用法(GC-MS)进行检测。结果表明:市售聚氯乙烯(PVC)材质书套中普遍检出了高浓度PAEs,其主要成分为邻苯二甲酸二(2-乙基)己酯(DEHP)。该检测方法提取效率高,线性范围较宽,回收率高且重现性好。     

几种常用塑料给水管道邻苯二甲酸酯检测方法研究

通过气相色谱-质谱联用法(GC-MS)对几种塑料给水管道中邻苯二甲酸酯(PAEs)的含量进行了检测,其中着重探讨了不同前处理及萃取方式对检测结果及检测效率的影响。结果表明:对样品进行研磨处理有利于提高检出精度;3种萃取方式(超声波萃取、搅拌萃取、索氏萃取)的萃取效率基本等同,均能满足快速检测的要求。对于3种常见的塑料给水管道——聚氯乙烯(PVC)管、聚乙烯(PE)管、无规共聚聚丙烯(PPR)管,仅PVC管及PE管中含有PAEs。     

超声波、微波萃取及其联用技术在中药有效成分提取中的应用

介绍了超声波萃取技术,微波萃取技术以及超声-微波协同萃取的原理和特点,并阐述这些技术在中药有效成分提取方面的应用。     

固相萃取-气质色谱联用法测定PVC管材中邻苯二甲酸酯类增塑剂的含量

通过试验研究萃取剂、萃取方式等样品的前处理条件,建立了一种固相萃取-气质色谱联用测定PVC管材中10余种邻苯二甲酸酯类增塑剂环境激素含量的方法,填补了PVC管材检测在此领域的空白。其他介质中邻苯二甲酸酯类增塑剂环境激素的测定可借鉴这种方法     

PVC玩具和儿童用品中6种限用邻苯二甲酸酯类增塑剂的同时测定

提出了气相色谱-质谱联用同时测定PVC玩具和儿童用品中6种限用增塑剂的方法,以乙酸乙酯为溶剂,采用微波萃取法提取PVC玩具和儿童用品中6种限用邻苯二甲酸酯类增塑剂,以DHP为内标进行定量。该方法平均回收率为91.15%~98.72%,RSD为1.98%~4.47%,检测限(S/N=5)分别为0.5 mg/L(DBP、BBP、DEHP、DNOP)和10 mg/L(DINP、DIDP)。     

用索氏提取-气相色谱法测定PVC管材中的邻苯二甲酸酯类增塑剂

建立了索氏提取-气相色谱法测定聚氯乙烯(PVC)等管材中6种国家限量邻苯二甲酸酯(PAEs)类增塑剂的方法。采用索氏提取作为前处理提取手段,通过正交试验对样品中PAEs类增塑剂的提取条件进行系统优化。结果表明:在一定范围内,该方法具有良好线性关系,相关系数在0.997~0.999之间,检测限为0.15~0.60 mg/kg,平均回收率84.2%~109%,相对标准偏差为1.33%~8.60%。方法简单高效,具有良好的重现性和灵敏度,适用于PVC等管材中PAEs类增塑剂的分析检测。     

色谱分析法在测定苯甲酸等物质中的应用

邻苯二甲酸酯（PAEs）作为一类化合物,在聚氧乙烯树脂,纤维素薄膜涂层和粘合剂中用作增塑剂。PAEs具有抗雄性激素作用,是一类内分泌干扰物。在日常生活中,可通过饮水、进食、化妆品和呼吸进入人体,对人体健康产生危害。本实验以Triton X-114为萃取剂,对微量的邻苯二甲酸酯类化合物的测定进行了分析研究。     

GC-MS法测定聚乙烯塑料袋中的邻苯二甲酸酯

建立了一种检测聚乙烯(PE)塑料袋中邻苯二甲酸酯(PAEs)类物质残留含量的方法。以正己烷为萃取溶剂,利用超声萃取法对样品中的PAEs进行了提取,随后采用气相色谱-质谱联用法(GC-MS)对其进行了定性、定量的检测。结果表明:利用该方法所得样品中PAEs的加标(16种PAEs混标)回收率分别在80.06%¹28.47%之间,检出限在0.057 5128.47%之间,检出限在0.057 5⁰.907 6 mg/kg之间,相对标准偏差(RSD)在6.92%0.907 6 mg/kg之间,相对标准偏差(RSD)在6.92%¹0.88%之间。该方法操作简便,重现性好。     

GC-MS法测定塑料产品中邻苯二甲酸酯类化合物

建立了塑料中邻苯二甲酸酯类化合物的气相色谱-质谱（GC-MS）测定方法.以四氢呋喃为萃取溶剂,用超声波萃取器塑料中的邻苯二甲酸酯类化合物,采用气相色谱-质谱联用仪（GC-MS）进行检测.邻苯二甲酸酯的线性相关系数r＞0.999,对实际加标样品的回收率在87％～110％之间,相对标准偏差（RSD）1.3％～4.8％,适合于塑料中邻苯二甲酸酯类化合物的测定.     

电子电器产品中含溴阻燃剂的萃取

电子电器产品中含溴阻燃剂的萃取方法有索氏萃取、自动索氏萃取、超声波萃取、超临器萃取、微波辅助萃取和快速溶剂萃取等.文章通过对比索氏萃取、微波辅助萃取和快速溶剂萃取并结合高效液相色谱法测定电子塑料产品中的含溴阻燃剂,探讨合适的萃取方法,实验结果表明,索氏萃取效果最好,回率91.8%～98.4%,RSD%=5,满足检测要求...     

微波萃取技术

介绍了一种新型的萃取方法——微波萃取及所用的试剂、设备和反应条件。通过与超声波法和索氏提取法的比较。发现微波萃取不仅有较高的回收率而且精度也很好。微波萃取具有操作时间短、溶剂量少、易于回收和自动控制水平高的特点。     

Comparison of Extraction Methods for Recovery of Astaxanthin from Haematococcus pluvialis

Solvent extraction, ultrasound assisted extraction (UAE), and microwave assisted extraction (MAE) were examined for the extraction of astaxanthin from Haematococcus pluvialis. In all cases, acetone was found to give the highest astaxanthin recovery compared with other selected solvents, i.e., methanol, ethanol, and acetonitrile. Among the various methods, MAE at 75°C for 5 min resulted in the highest astaxanthin recovery (74 ± 4%).     

原子吸收光谱的样品前处理方法进展

概括了常用的原子吸收光谱的前处理技术,重点介绍了最新现代原子吸收光谱前处理技术和这些前处理技术在环境样品、食品样品、人体组织样品和土壤样品分析中的应用。这些新的技术包括,超声波辅助萃取,微波辅助萃取,微波消解,浊点萃取技术,纳米材料运用于萃取技术,非完全消化技术,悬浮液进样法,在线富集等。     

Kinetic study of nordihydroguaiaretic acid recovery from Larrea tridentata by microwave‐assisted extraction

BACKGROUND: Nordihydroguaiaretic acid (NDGA) is a powerful antioxidant with biological activities of great interest in several health areas, including antiviral, cancer chemopreventive, and antitumorgenic. Little information is available on extraction methods of NDGA from Larrea tridentata. Hence, the aim of this study was to develop a rapid and effective microwave‐assisted extraction (MAE) method for NDGA recovery from Larrea tridentata leaves, and to compare the results obtained with those found using conventional heat‐reflux extraction (HRE). RESULTS: Extraction time for similar NDGA yields was significantly reduced from 18 to 1 min when MAE was used instead of HRE. Optimum conditions for NDGA extraction (3.79 ± 0.65%) consisted in using 50% methanol as extraction solvent in a solid/liquid ratio of 1/10 g mL^?1. Micrographs demonstrated that the improvement in NDGA extraction by MAE might be related to a greater extent of cell rupture of the plant material. Extracts obtained by MAE exhibited antiradical activity only slightly lower than those obtained by HRE. CONCLUSIONS: MAE proved to be a faster and more efficient method for NDGA extraction from Larrea tridentata leaves than HRE. The better results for NDGA extraction by MAE might be explained by the greater extent of cell rupture of plant material during the extraction process. Copyright © 2010 Society of Chemical Industry     

微波辅助萃取煤的实验研究

在微波辅助下,以神府煤为主要研究对象,四氢呋喃、丙酮、甲醇为溶剂,考察了萃取温度、时间、溶剂量及煤粒度对萃取率的影响,结果显示:使上述3种沸点接近的不同溶剂萃取率达到最佳值,所需要的萃取温度、溶剂量及煤粒度相差大;同时探讨了以四氢呋喃、丙酮、N,N-二甲基甲酰胺为溶剂,对不同变质程度煤的微波辅助萃取效果,结果是变质程度相似的煤在相同萃取条件下萃取率不同。运用红外光谱现代分析技术,对神府脱灰煤和四氢呋喃抽提残煤的结构进行对比分析,结果表明萃取并没有破坏煤的大分子结构。     

Optimization of Microwave‐Assisted Extraction of Flavonoid from Radix Astragali using Response Surface Methodology

Abstract

Response surface methodology (RSM) was applied to predict optimum conditions for microwave‐assisted extraction (MAE) of flavonoid from Radix Astragali. A central composite design was used to monitor the effect of temperature, extraction time, solvent‐to‐material ratio, and the ethanol concentration on yield of total flavanoid (TFA). Optimum extraction conditions were predicted as 108.2°C, 26.7 min, 23.1 ml/g solvent‐to‐material ratio and 86.2% ethanol. The maximum yield 1.234±0.031 mg/g was close to the yield of Soxhlet and higher than that of ultrasound assisted extraction and heat reflux extraction. MAE was an effective alternative to conventional extraction methods.     

微波辅助萃取-GC/MS联用分析蜂胶挥发油

用均匀实验设计,二次多项式逐步回归法,优化了蜂胶挥发油的微波辅助萃取工艺,最佳条件为:以蜂胶为原料,石油醚为溶剂,萃取温度30℃,按蜂胶10g、石油醚110mL的比例进行萃取,萃取时间32min,重复提取2次,在此条件下,蜂胶挥发油提取率为13.83%。与溶剂法相比,微波辅助萃取法提取时间缩短为溶剂萃取法的2/45,蜂胶挥发油提取率提高至溶剂萃取法的1.51倍。通过GC-MS分析蜂胶挥发油,共分离得到54个峰,鉴定了52种,占总峰面积的98.63%。主要成分为17-三十五碳烯(21.36%),二十七烷(11.96%),1-十九烯(9.09%),二十九烷(7.96%),正二十一烷(6.26%),1-二十二烯(6.19%),羊毛甾醇醋酸酯(Lanosta-8,24-dien-3β-ol,acetate)(5.57%),萜烯类及酯类衍生物总相对质量分数为17.86%。     

Assessment of Scale‐Up Parameters of Microwave‐Assisted Extraction via the Extraction of Flavonoids from Cocoa Leaves

Microwave‐assisted extraction (MAE) is a promising technique for the extraction of flavonoid compounds from plants. However, it is difficult to scale up due to the complex mass transfer involved. This has prompted the study of parameters for scaling up the system by considering energy‐related parameters, i.e. the nominal power density and the absorbed power density (APD). Modeling of MAE of flavonoid compounds from cocoa (Theobroma cacao L.) leaves using the film theory model was performed for this purpose. Operating parameters such as the sample particle size, the solvent‐to‐feed ratio, and the microwave irradiation power were also included in the kinetic study. The APD exhibited its aptitude as scaling‐up parameter as it can characterize both the extraction kinetics and the extraction yields of MAE. Furthermore, it can be used as a reference for predicting the optimum extraction time of MAE under various heating conditions.     

A Review on Extraction Techniques and Its Future Applications in Industry

Extraction is a mandatory process for most of the industries, especially in the food processing industry to obtain the targeted compounds from various sources such as plant or seed samples. This review paper provides information about various extraction techniques that are normally used in the edible oil extraction industry. Five extraction techniques are presented in this paper. Among all the techniques presented in this paper, pressing and solvent extraction methods are considered as traditional techniques while supercritical fluid extraction, microwave assisted extraction, and ultrasound assisted extractions are considered as advanced techniques. Both advantages and disadvantages of supercritical fluid extraction, microwave assisted and ultrasound assisted extractions are discussed. Furthermore, the parameters that would affect the output of each technique are included in each section. Nowadays, research is going on to further enhance the extraction method to obtain a higher extraction yield or increase the quality of the extraction product. The enhancement can be either combining two or more extraction techniques into one complete process or modifying the available technique alone. Therefore, the theoretical knowledge provided in this review will be useful for future researchers who are interested in enhancing the extraction techniques. Practical Applications : Extraction is a mandatory process in edible oil extraction industry. Extraction industry is always looking for a process which is high efficiency and low extraction cost. Therefore, various advanced techniques or treatments are applied to optimize the oil yield and shorten the extraction time. This paper provides a review on various techniques by summarizing both advantages and disadvantages of each technique. The information can be very useful for improving the current extraction technique to further optimize the oil yield or enhance the quality of oil.