Microwave-assisted extraction chromatography

Shen G, Lee HK. Determination of triazines in soil by microwave-assisted extraction followed by solid-phase microextraction and gas chromatography-mass spectrometry. J. Chromatogr. A 2003 985 167-174. 

Lopez-Avila et al. [59] used microwave assisted extraction to assist the extraction of polyaromatic hydrocarbons from soils. Another extraction method was described by Hartmann [60] for the recovery of polyaromatic hydrocarbons in forest soils. The method included saponification of samples in an ultrasonic bath, partitioning of polyaromatic hydrocarbons into hexane, extract cleanup by using solid-phase extraction, and gas chromatography-mass spectrometric analysis using deuterated internal standards. Polyaromatic hydrocarbons were thermally desorbed from soils and sediments without pretreatment in another investigation [61]. 

Lopez-Avila et al. [59] have described a microwave assisted extraction procedure for the separation of polyaromatic hydrocarbons from sediments. Tan [71] described a rapid sample preparation technique for analysing polyaromatic hydrocarbons in sediments. Polyaromatic hydrocarbons are removed from the sediment by ultrasonic extraction and isolated by solvent partition and silica gel column chromatography. The sulphur removal step is combined into the ultrasonic extraction procedure. Identification of polyaromatic hydrocarbon is carried out by gas chromatography alone and in conjunction with mass spectrometry. Quantitative determination is achieved by addition of known amounts of standard compounds using flame ionization and multiple ion detectors. 

Heise and Litz [26] investigated the extraction behaviour of surfactants (LAS, NPEO and cationics) from sand comparing Soxhlet extraction, accelerated solvent extraction (ASE) and microwave-assisted extraction. Fractionation of the three surfactant types anionic, non-ionic and cationic, was accomplished by column chromatography with aluminium oxide. Soxhlet extraction and ASE of spiked sand with methanol—stored during 7 days prior to extraction—gave similar recoveries for both LAS and NPEO with values between 88 and 116%. Less efficient extraction was achieved by microwave extraction (79% for NPEO). 

B. Marcato and M. Vianello, Microwave-assisted extraction by fast sample preparation for the systematic analysis of additives in polyolefines by high-performance hquid chromatography. J. Chromatogr.A 869 (2000) 285-300. 

Microwave-assisted extraction coupled with gas chromatography-electron capture negative chemical ionization mass spectrometry (i. e., MAE-GC-EC-NCI-MS) was described for the simplified determination of imidazolinone herbicides in soil at the ppb level [715]. 

BDE 47, 99 100 Fish (Muscle tissues of salmon and conger eel and liver tissues of sea bass) green mussel Homogenization, MSPD with sodium sulfate, microwave-assisted extraction with pentane-dichloromethane (1 1) and purification with GPC Gas Chromatography (DB-5MS) Q-MS <100 ng/Kg [41]... 

In extraction, analyte is dissolved in a solvent that does not necessarily dissolve the entire sample and does not decompose the analyte. In a typical microwave-assisted extraction of pesticides from soil, a mixture of soil plus acetone and hexane is placed in a Teflon-lined bomb (Figures 28-8 and 28-13) and heated by microwaves to 150°C. This temperature is 50° to 100° higher than the boiling points of solvents at atmospheric pressure. Pesticides dissolve, but the soil remains behind. The liquid is then analyzed by chromatography. 

MH Akhtar, M Wong, SRH Crooks, A Sauve. Extraction of incurred sulphamethazine in swine tissue by microwave assisted extraction and quantification without clean-up by high performance liquid chromatography following derivatization with dimethylaminobenzaldehyde. Food Additiv Con-tarn 15 542-549, 1998. 

Weichbrodt M, Vetter W, Scholz E, Luckas B, Reinhardt K (1999) Determination of Organochlorine Levels in Antarctic Skua and Penguin Eggs by Application of Combined Focused Open-Vessel Microwave Assisted Extraction, Gel-Permeation Chromatography, Adsorption Chromatography, and GC/ECD. Inter J Environ Anal Chem 73 309... 

Lopez-Avila et al. [107] showed that microwave-assisted extraction of pesticides and polycyclic aromatic hydrocarbons from soil is a viable alternative to Soxhlet extraction and needs a smaller sample volume and extraction time [108,109]. These techniques have also been compared in the case of chlorophenols. Lopez-Avila et al. compared microwave-assisted extraction with electron capture gas chromatography to ELISA for the determination of polychlorinated biphenyls in soils. Both techniques are applicable to field screening and monitoring applications. Microwave-assisted extraction [111, 112] and solid-phase microextraction [113] have been applied to the extraction of pesticides from soil. It was observed by these and other workers [114] that the selectivity of microwave-assisted extraction is highly dependent on the soil composition. 

Other techniques that have been used to determine polycyclic aromatic hydrocarbons in soil extracts include ELISA field screening [86], micellar elec-tr okinetic capillary chromatography [ 87], supersonic jet laser-induced fluorescence [88,89], fluorescence quenching [90], thermal desorption gas chromatography-mass spectrometry [81,90,100], microwave-assisted extraction [91], thermal desorption [92], immunochemical methods [93,94], electrophoresis [96], thin layer chromatography [95], and pyrolysis gas chromatography [35]. 

Atrazine, simazine, terbuthylazine, molinate Solid-phase microwave-assisted extraction using methanol Gas chromatography-mass spectrometry. Limit of detection 1-10 ng/g [382]... 

Examples of this type of herbicide are imazapyr, m-imazamethabenz, p-imazamethabenz, m,p-imazamethabenzmethyl, imazethapyr and imazaquin. Imazapyr has been determined at the xg/kg level in 0.1 M ammonium acetate extracts of soil by microwave-assisted extraction using electron capture negative chemical ionisation mass spectrometry [432]. High-performance liquid chromatography with UV detection at 250 nm has been used to determine imazapyr in methanol extracts of soil [433]. 

Yang, L. and J.W. Lam. 2001. Microwave-assisted extraction of butyltin compounds from PACS-2. Sediment for quantitation by high-performance liquid chromatography inductively coupled plasma mass spectrometry. J. Anal. At. Spectrom. 16 724—731. 

M. Vilano, R. Rubio, Determination of arsenic species in oyster tissue by microwave-assisted extraction and liquid chromatography-atomic fluorescence detection, Appl. Organomet.Chem., 15 (2001), 658-666. 

R. Tukai, W. A. Maher, I. J. McNaught, M. Ellwood, Measurement of arsenic species in marine macroalgae by microwave-assisted extraction and high performance liquid chromatography-inductively coupled plasma mass spectrometry, Anal. Chim. Acta, 457 (2002), 173-185. 

C. S. Chiou, S. J. Jiang, K. S. K. Danadurai, Determination of mercury compounds in fish by microwave-assisted extraction and liquid chromatography-vapor gener-ation-inductively coupled plasma mass spectrometry, Spectrochim. Acta, 56B (2001), 1133-1142. 

Keywords Pressurized liquid extraction supercritical fluid extraction ultra-sound-assisted extraction microwave-assisted extraction matrix solid-phase extraction high-performance liquid chromatography gas chromatography liquid-liquid extraction solid phase extraction column chromatography... 

Sun, Y. Liao, X. Wang, Z. Hu, X. Chen, F. 2007. Optimization of microwave-assisted extraction of anthocyanins in red raspberries and identification of anthocyanin of extracts using high-performance liquid chromatography mass spectrometry. Eur. Food Res. Tech. 225 511-523. 

Ma, Y., Cui, K., Zeng, F. Microwave-assisted extraction combined with gel permeation chromatography and silica gel cleanup followed by gas chromatography-mass spectrometry for the determination of organophosphoms flame retardants and plasticizers in biological samples. Anal. Chim. Acta 786, 47 (2013)... 

Dongjin, P. Soyoung, L. Rapid purification of micro-cystin-LR using supercritical fluid exteraction and flash chromatography. Anal. Lett. 2002, 35 (9), 1591-1602. Camel, V. Recent extraction techniques for solid matrices—Supercritical fluid extraction, pressurized fluid extraction and microwave-assisted extraction Their potential and pitfalls. Analyst 2001, 126, 1182-1193. 

Keywords Antioxidants Gas chromatography (GC) Microwave assisted extraction (MAE) Polymers... 

Pedersen SN, Lindholst C (1999) Quantification of the xenoestrogens 4- tert. -octylphenol and bisphenol A in water and in fish tissue based on microwave assisted extraction, solid-phase extraction and liquid chromatography-mass spectrometry. J Chromat A 864, 17-24. 

This overview is focused on the on-line coupling of pressurized liquid extraction (PLE), microwave-assisted extraction (MAE), supercritical fluid extraction (SEE) and sonication-assisted extraction (SAE) with liquid and gas chromatography for the analysis of solid agricultural and food samples. In addition, head-space techniques and direct thermal extraction are discussed. 

Even though the interest in microwave-assisted extraction (MAE) has increased during the last 10 years, this technique has not been utilized much in food and feed applications. Only a few papers can be found with the combination of POPs and food/feed samples. This may be because MAE applications frequently require laborious and tedious clean-up of the extracts before final analysis. In some cases, only a simple filtration or centrifugation may be sufficient to separate the solid matrix from the extract but since MAE most often is more exhaustive than selective, extensive clean-up procedures based on for example solid-phase extraction is commonly needed for removal of interfering compounds (73-75). Other techniques that have been used for clean-up of MAE extracts are gel permeation chromatography (75), solid-phase micro extraction (77, 78), and liquid-liquid extraction (79). 

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