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1.
Bouaid A Martín-Esteban A Fernández P Cámara C 《Fresenius' Journal of Analytical Chemistry》2000,367(3):291-294
A simple and rapid microwave assisted extraction (MAE) method is presented for the determination of atrazine and four organophosphorus pesticides (parathionmethyl, chlorpyriphos, fenamiphos and methidathion) in orange peel. The experimental variables that affect the MAE method, such as temperature, sample quantity, extraction time, nature and volume of organic solvents, were optimized. The MAE method was optimized using an experimental design. The results suggest that temperature and sample quantity are statistically significant factors. It was concluded that the five pesticides could be efficiently extracted from 1.5-2.5 g of orange peel with 10 mL of hexane/acetone (1: 1) mixture at 90 degrees C in 9 min with microwave power set at 50% (475 W). After optimization these factors, recoveries ranged from 93 to 101% with a relative standard deviation ranging from 1 to 3%. The extracts were analyzed by gas chromatography with a nitrogen-phosphorus detector (GC-NPD). 相似文献
2.
《Journal of separation science》2005,28(13):1485-1492
SPE is a commonly applied technique for preconcentration of pesticides from water samples. Microwave‐assisted extraction (MAE) technique is the extraction applied for preconcentration of different compounds from solid samples. SPE coupled with MAE is capable of preconcentrating these compounds from water samples too. This investigation was aimed at improving the efficiency of atrazine, alachlor, and α‐cypermethrin pesticide extraction from the spiked water samples applying SPE followed by MAE. In this way, MAE served for elution of pesticides from C18‐extraction disks with solvent heated by microwave energy. Various elution conditions were tested for their effects on the extraction efficiency of the SPE–MAE combined technique. Several parameters, such as elution solvent volume (mL), elution temperature (°C), and duration of elution (min), affect the extraction efficiency of the SPE–MAE coupled system and need to be optimized for the selected pesticides. In order to develop a mathematical model, 15 experiments were performed in the central composite design. The equation was then used to predict recoveries of the pesticides under specific experimental conditions. Optimization of microwave extraction was accomplished using the genetic algorithm approach. Best results were achieved using 20 mL of ethanol at 60°C. Optimal hold time was 5 min and 24 s. The SPE–MAE combination was also compared with the conventional SPE extraction technique with elution of a nonpolar or a moderately polar compound with nonpolar solvents. 相似文献
3.
QuEChERS结合气相色谱-质谱法测定农产品中杀螨剂和拟除虫菊酯农药残留 总被引:2,自引:0,他引:2
建立了QuEChERS-改性多壁碳纳米管提取净化,气相色谱-质谱法同时检测农产品中1种杀螨剂和8种拟除虫菊酯农药的分析方法。样品经水浸润后,以乙酸乙酯-正己烷混合溶剂提取,再以适量改性多壁碳纳米管填料净化提取液,净化液以Shimadzu Rtx-1701毛细管色谱柱为分离柱,采用质谱测定和确证,选择离子模式监测,外标法定量。在优化实验条件下,9种农药在0.010~1.0μg/mL范围内具有良好的线性关系,相关系数为0.9840~0.9977,检出限(S/N=3)为2.2~6.2μg/kg。3个加标水平下的平均回收率为76.7%~107%,相对标准偏差为3.1%~9.5%。该方法准确、灵敏度高、操作简单、快速,可满足新会陈皮等农产品中上述9种农药残留同时测定的要求。 相似文献
4.
E. Vázquez Blanco P. López Mahía S. Muniategui Lorenzo D. Prada Rodríguez E. Fernández Fernández 《Analytical and bioanalytical chemistry》2000,366(3):283-288
Microwave energy was applied to extract polycyclic aromatic hydrocarbons (PAHs) and linear aliphatic hydrocarbons (LAHs) from marine sediments. The influence of experimental conditions, such as different extracting solvents and mixtures, microwave power, irradiation time and number of samples extracted per run has been tested using real marine sediment samples; volume of the solvent, sample quantity and matrix effects were also evaluated. The yield of extracted compounds obtained by microwave irradiation was compared with that obtained using the traditional Soxhlet extraction. The best results were achieved with a mixture of acetone and hexane ¶(1?:?1), and recoveries ranged from 92 to 106%. The extraction time is dependent on the irradiation power and the number of samples extracted per run, so when the irradiation power was set to 500 W, the extraction times varied from 6 min for 1 sample to 18 min for 8 samples. Analytical determinations were carried out by high-performance liquid chromatography (HPLC) with an ultraviolet-visible photodiode-array detector for PAHs and gas chromatography (GC) using a FID detector for LAHs. To test the accuracy of the microwave-assisted extraction (MAE) technique, optimized methodology was applied to the analysis of standard reference material (SRM 1941), obtaining acceptable results. 相似文献
5.
以自制改性多壁碳纳米管(MWNTs)和N-丙基乙二胺(PSA)填料分层填装的双层固相萃取柱为净化柱,建立了测定陈皮及其制品中11种有机磷农药残留的分析方法。样品经乙酸乙酯提取、离心后,固相萃取柱净化,净化液经Agilent RTS-1701毛细管柱分离,火焰光度检测器检测,外标法定量。考察了填料类型、填料用量、洗脱方式等因素对提取效率的影响。在优化条件下,11种有机磷农药检测的线性范围为0.020~1.0 mg/L,相关系数为0.9990~0.9998,检出限为3.5~9.6 μ g/kg。样品在10、25、100 μg/kg 3种水平下的加标回收率为50.8%~109%,相对标准偏差为2.7%~8.5%。该法准确度和灵敏度高、操作简单、快速,检出限能满足对有机磷农药残留的限量要求。自制固相萃取柱可降低成本,值得推广应用。 相似文献
6.
Furkan Burak Şen Yavuz Selim Aşçı Burcu Bekdeşer Reşat Apak 《Analytical letters》2019,52(17):2751-2763
AbstractThe recovery of antioxidants from basil (Ocimum basilicum L.) was modeled with the aid of response surface methodology (RSM) using microwave-assisted extraction (MAE). Face-centered central design (FCCD) was employed to optimize the MAE operational parameters including the extraction time (1 to 7?min), extraction temperature (30 to 120?°C), solid-to-solvent ratio (0.1 to 0.4), and solvent concentration (20 to 80% ethanol, v/v), and to obtain the best possible combinations of these parameters for a high antioxidant yield from basil. The total antioxidant capacity (TAC) was expressed in trolox (TR) equivalents per gram of dried sample (DS). Three of the operational parameters (temperature, extraction time and solvent concentration) were shown to have significant effect on the extraction efficiency of antioxidants in basil extracts (p?<?0.05). The solvent concentration was shown to be the most significant factor on antioxidant yield obtained by MAE. There was a close relationship between experimental and predicted values using the proposed method. This optimized MAE method shows an application potential for the efficient extraction of antioxidants from basil in the food and pharmaceutical industries. 相似文献
7.
Three types of solvent extraction methods (by soxhlet, sonicator and microwave) for pesticide recoveries in solid matrices were compared and evaluated using the standard addition method. Variables (solvent and extraction time) for the optimization of microwave assisted extraction (MAE) were also studied. Three organochlorine pesticides (BHC, DDE, and Dildrin) were chosen for this particular study because of their great presence in the soil where the samples were collected and their positive association with the risk of breast cancer. Comparison of the results obtained indicates that the efficiency of extraction varies, depending on the matrices and the pesticides analyzed. The study focused on the variation in the extraction quantities of different methods in different matrices. The extraction conditions were optimized for MAE with a single matrix (bark) and applied to the rest in order to study the variability in results. Gas chromatography with an electron capture detector (GC–ECD) was used for analysis of the extracts. The results show that even though the use of MAE improved extraction in some of the matrices studied, the extraction method must be optimized whenever a new matrix is evaluated. A statistical comparison indicated that pesticide recoveries and method reproducibility of microwave extraction compared less favorably with the conventional soxhlet method in some of the matrices, whereas the sonicator method was not found to be as efficient as the others. 相似文献
8.
Xinsheng Fang Yingzi Wang Jianhua Wang Jin Zhang Xin Wang 《Journal of separation science》2013,36(16):2672-2679
An optimized microwave‐assisted extraction (MAE) method and RP‐HPLC method were developed for the simultaneous extraction and determination of rutin, forsythiaside A, and phillyrin in the fruits of Forsythia suspensa. The key parameters of the open‐vessel MAE process were optimized. A mixed solvent of methanol and water (70:30, v/v) was most suitable for the simultaneous extraction of the three components. The sample was soaked for 10 min before extraction. The optimized conditions were: microwave power 400 W, temperature 70°C, solvent‐to‐material ratio 30 mL/g, and extraction time 1 min. Compared to conventional extraction methods, the proposed method can simultaneously extract the three components in high yields and was proved to be a more rapid method with a lower solvent consumption. The optimized HPLC–photodiode array detection analysis was validated to have good linearity, precision, accuracy, and sensitivity. The developed MAE followed by RP‐HPLC is a fast and appropriate method for the simultaneous extraction and determination of rutin, forsythiaside A, and phillyrin in the fruits of F. suspensa. 相似文献
9.
The aim of this study was to evaluate the efficiency of microwave-assisted extraction (MAE) for the analysis of organophosphorus (OP) and pyrethroid (PYR) pesticides in green onions by GC/MS. We optimized MAE extraction solvent, temperature, and time by using a certified reference material. As a result, the concentrations of two OP and two PYR target pesticides obtained by MAE with acetonitrile at 110 degrees C for 10 min were in good agreement with certified concentrations and comparable to the results by homogenization used as reference extraction technique. When the recovery test, performed by spiking the target pesticides into blank samples (5.0 g), was carried out with our optimized MAE conditions, mean recoveries of 16 OP and 10 PYR pesticides were 72-108% for a 1.0 pg spiking level and 70-119% for a 0.2 microg level. These results were acceptable according to the validation guideline for testing method of agricultural chemicals in food by Ministry of Health, Labour, and Welfare in Japan. The results suggested that MAE can be used for the analysis of OP and PYR pesticides in green onions. 相似文献
10.
11.
Ziming Wang Xin Zhao Xu Xu Lijie Wu Rui Su Yajing Zhao Chengfei Jiang Hanqi Zhang Qiang Ma Chunmei Lu Deming Dong 《Analytica chimica acta》2013
A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction (μ-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave μ-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in μ-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave μ-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 °C for 10 min. The extracts obtained by MAE-μ-SPE were directly analyzed by GC–MS without any clean-up process. The recoveries were in the range of 93.5–104.6%, and the relative standard deviations were lower than 8.7%. 相似文献
12.
Xinsheng Fang Jianhua Wang Xiaoliang Yu Guohui Zhang Jinpeng Zhao 《Journal of separation science》2010,33(8):1147-1155
An optimized microwave‐assisted extraction (MAE) method and an efficient HPLC analysis method were developed for fast extraction and simultaneous determination of oleanolic acid and ursolic acid in the fruit of Chaenomeles sinensis. The open vessel MAE process was optimized by using a central composite experimental design. The optimal conditions identified were microwave power 600 W, temperature 52°C, solvent to material ratio 32 mL/g and extraction time 7 min. The results showed that MAE is a more rapid extraction method with higher yield and lower solvent consumption. The HPLC–photodiode array detection analysis method was validated to have good linearity, precision, reproduction and accuracy. Compared with conventional extraction and analysis methods, MAE–HPLC–photodiode array detection is a faster, convenient and appropriate method for determination of oleanolic acid and ursolic acid in the fruits of C. sinensis. 相似文献
13.
14.
Optimization of microwave-assisted extraction of hydrocarbons in marine sediments: comparison with the Soxhlet extraction method 总被引:4,自引:0,他引:4
Vázquez Blanco E López Mahía P Muniategui Lorenzo S Prada Rodríguez D Fernández Fernández E 《Fresenius' Journal of Analytical Chemistry》2000,366(3):283-288
Microwave energy was applied to extract polycyclic aromatic hydrocarbons (PAHs) and linear aliphatic hydrocarbons (LAHs) from marine sediments. The influence of experimental conditions, such as different extracting solvents and mixtures, microwave power, irradiation time and number of samples extracted per run has been tested using real marine sediment samples; volume of the solvent, sample quantity and matrix effects were also evaluated. The yield of extracted compounds obtained by microwave irradiation was compared with that obtained using the traditional Soxhlet extraction. The best results were achieved with a mixture of acetone and hexane (1:1), and recoveries ranged from 92 to 106%. The extraction time is dependent on the irradiation power and the number of samples extracted per run, so when the irradiation power was set to 500 W, the extraction times varied from 6 min for 1 sample to 18 min for 8 samples. Analytical determinations were carried out by high-performance liquid chromatography (HPLC) with an ultraviolet-visible photodiode-array detector for PAHs and gas chromatography (GC) using a FID detector for LAHs. To test the accuracy of the microwave-assisted extraction (MAE) technique, optimized methodology was applied to the analysis of standard reference material (SRM 1941), obtaining acceptable results. 相似文献
15.
Essential oil of Salvia mirzayanii cultivated in Iran was obtained by microwave assisted extraction (MAE) procedures. The essential oil was analysed by capillary gas chromatography using flame ionisation and mass spectrometric detections. The effects of different parameters, such as microwave power, temperature, time and type of solvent on the MAE of Salvia mirzayanii oil were investigated. Results of the two-level fractional factorial design (2(4-1)) based on an analysis of variance demonstrated that only the power, temperature and type of solvent were statistically significant. Optimal conditions for the extraction of essential oils were obtained by using Box-Behnken design. For optimum recovery of essential oil the variables power, temperature and solvent values were 115?W, 50°C and 14?s, respectively. Under the optimised experimental conditions, the extraction yield of microwave assisted extraction was 11.2% (w/w). 相似文献
16.
《Analytical letters》2012,45(7):1118-1133
Melamine attracts considerable attention because of its toxicity. The determination of melamine in seafood was performed by gas-chromatography–mass spectrometry, using an optimized version of a method adopted by the U.S. Food and Drug Administration. The melamine was extracted by closed-vessel microwave-assisted solvent extraction (MAE), as a valid alternative in sample preparation, to reduce analysis time and provide less ambiguous data. The procedure was optimized by means of experimental factorial design considering the three main variables that affect this process: microwave oven power, the maximum temperature inside the extraction tube, and the hold time. The recovery of melamine in spiked samples was used as the elemental response value of the design. Temperature and hold time had a more positive effect on the response than the microwave power. A significant positive interaction was observed between oven power and hold time. A temperature of 70°C and a hold time of 1 min gave a recovery of 92 ± 5% for a microwave power of 600 W. Under these conditions, the total microwave extraction time was approximately 2 minutes, a much shorter time compared to the ultrasonic bath, which required a total time of 40 min. The repeatability of the method was approximately 3%. The limits of quantification were 0.55 mg kg?1 for MAE and 1.9 mg kg?1 for the ultrasonic bath; the linearity was confirmed up to 10 mg kg?1. In conclusion, the MAE procedure was shown to be an excellent alternative to the official method. 相似文献
17.
Microwave-assisted extraction versus Soxhlet extraction in the analysis of 21 organochlorine pesticides in plants 总被引:5,自引:0,他引:5
Barriada-Pereira M Concha-Graña E González-Castro MJ Muniategui-Lorenzo S López-Mahía P Prada-Rodríguez D Fernández-Fernández E 《Journal of chromatography. A》2003,1008(1):115-122
A method to determine 21 organochlorine pesticides in vegetation samples using microwave-assisted extraction (MAE) is described and compared with Soxhlet extraction. Samples were extracted with hexane–acetone (1:1, v/v) and the extracts were cleaned using solid-phase extraction with Florisil and alumine as adsorbents. Pesticides were eluted with hexane–ethyl acetate (80:20, v/v) and determined by gas chromatography and electron-capture detection. Recoveries obtained (75.5–132.7% for Soxhlet extraction and 81.5–108.4% for MAE) show that both methods are suitable for the determination of chlorinated pesticides in vegetation samples. The method using microwave energy was applied to grass samples from parks of A Coruña (N.W. Spain) and to vegetation from the contaminated industrial area of Torneiros (Pontevedra, N.W. Spain). 相似文献
18.
Herbert P Morais S Paíga P Alves A Santos L 《Analytical and bioanalytical chemistry》2006,384(3):810-816
A new procedure for determining eleven organochlorine pesticides in soils using microwave-assisted extraction (MAE) and headspace
solid phase microextraction (HS-SPME) is described. The studied pesticides consisted of mirex, α- and γ-chlordane, p,p′-DDT, heptachlor, heptachlor epoxide isomer A, γ-hexachlorocyclohexane, dieldrin, endrin, aldrine and hexachlorobenzene. The
HS-SPME was optimized for the most important parameters such as extraction time, sample volume and temperature. The present
analytical procedure requires a reduced volume of organic solvents and avoids the need for extract clean-up steps. For optimized
conditions the limits of detection for the method ranged from 0.02 to 3.6 ng/g, intermediate precision ranged from 14 to 36%
(as CV%), and the recovery from 8 up to 51%. The proposed methodology can be used in the rapid screening of soil for the presence
of the selected pesticides, and was applied to landfill soil samples. 相似文献
19.
The microwave assisted extraction (MAE) technique has been evaluated for the extraction of active pharmaceutical ingredients (API) from various solid dosage forms. Using immediate release tablets of Compound A as a model, optimization of the extraction method with regards to extraction solvent composition, extraction time and temperature was briefly discussed. Complete recovery of Compound A was achieved when samples were extracted using acetonitrile as the extraction solvent under microwave heating at a constant cell temperature of 50 degrees C for 5 min. The optimized MAE method was applied for content uniformity (single tablet extraction) and potency (multiple tablets extraction) assays of release and stability samples of two products of Compound A (5 and 25mg dose strength) stored at various conditions. To further demonstrate the applicability of MAE, the instrumental extraction conditions (50 degrees C for 5 min) were adopted for the extraction of montelukast sodium (Singulair) from various solid dosage forms using methanol-water (75:25, v/v) as the extraction solvent. The MAE procedure demonstrated an extraction efficiency of 97.4-101.9% label claim with the greatest RSD at 1.4%. The results compare favorably with 97.6-102.3% label claim with the greatest RSD at 2.9% obtained with validated mechanical extraction procedures. The system is affordable, user-friendly and simple to operate and troubleshoot. Rapid extraction process (7 min/run) along with high throughput capacity (up to 23 samples simultaneously) would lead to reduced cycle time and thus increased productivity. 相似文献
20.
M. Barriada-Pereira M.J. González-Castro P. López-Mahía D. Prada-Rodríguez E. Fernández-Fernández 《Talanta》2007,71(3):1345-1351
A method to determine organochlorine pesticides in horticultural samples (lettuce, tomato, spinach, potato, turnip leaf and green bean) using pressurized liquid extraction (PLE) is described and compared with microwave assisted extraction (MAE). Significant parameters affecting PLE procedure such as temperature, static extraction time and extraction solvent were optimised and discussed. Clean-up of extracts was performed by solid phase extraction (SPE) using a carbon cartridge as adsorbent. Pesticides were determined by gas chromatography and electron capture detection (GC-ECD). Analytical recoveries obtained were ca. 100% and the relative standard deviations were lower than 15% for most of the studied pesticides with the proposed methods in each analysed matrix. 相似文献