Comparison of microwave and

Table 3.28 Comparison of microwave and reflux extraction solvent efficiencies for additives in LLDPE...

To illustrate these trends, we now present some typical illustrative examples. These have been selected because strict comparisons of microwave and classical heating activation were made under similar conditions (time, temperature, pressure, etc.. ..) for the same reaction medium and using, preferably, a monomode system equipped with stirring. They mostly involve reactions performed under solvent-free conditions or, occasionally, in a nonpolar solvent, because these conditions are also favorable for observation of microwave effects. 

Hunt, N. C. A., Attanoos, R., and Jasani, B. 1996. High temperature antigen retrieval and loss of nuclear morphology A comparison of microwave and autoclave techniques. J. Clin. Pathol. 49-101-110. 

Comparison of microwave and hydrothermal approaches to the synthesis of tin-containing mesoporous molecular sieves... 

P. Colombo, G. A. Danko, and R. Silberglitt, Production of SiC and SiOC from preceramic polymers comparison of microwave and conventional heating, in Ceramics - Getting into the 2000s, Part C (Section F), Techna Sri, Faenza, 1998, pp. 353-360. 

Table 8. Comparison of microwave and thermal activation in copolymerization reactions. Reprinted from (2000) J Polym Sci A Polym Chem 38 1379 [84] with permission...

Comparison of microwave and thermal activation in copolymerization reactions... 

Bacsa B, Horvati K, Bosze S et al (2008) Solid-phase synthesis of difficult peptide sequences at elevated temperatures a critical comparison of microwave and conventional heating technologies. J Org Chem 73 7532-7542... 

DEVECE C, RODRIGUEZ LOPEZ J N, FENOLL L G, TUDELA J, CATALA J M, DE LOS REYES E and GARCIA CANOVAS F (1999) Enzyme inactivation analysis for industrial blanching applications comparison of microwave, conventional, and combination heat treatments on mushroom polyphenoloxidase activity , J g-nc Food Chem, 47 (11) 4506-11. 

Table 3.4 contains a comparison of microwave extraction with other sample preparation procedures. MAE compares favourably with Soxhlet/Soxtec and... 

HPLC-QFAAS is also problematical. Most development of atomic plasma emission in HPLC detection has been with the ICP and to some extent the DCP, in contrast with the dominance of the microwave-induced plasmas as element-selective GC detectors. An integrated GC-MIP system has been introduced commercially. Significant polymer/additive analysis applications are not abundant for GC and SFC hyphenations. Wider adoption of plasma spectral chromatographic detection for trace analysis and elemental speciation will depend on the introduction of standardised commercial instrumentation to permit interlaboratory comparison of data and the development of standard methods of analysis which can be widely used. 

A definite microwave effect is involved when strict comparisons of MW and A activation are considered and is compatible with the mechanistic assumption that a very polar TS is developed (Scheme 3.12). 

Very few results on selectivity effects are available due to a lack of strict comparisons between microwave and A activation and in which kinetic details of reactions have been described. Reports of the effect of microwaves on selectivity up to 1997 have been reviewed by Langa et al. [57]. 

Tab. 8.5 Comparison of conventional and microwave heating for preparation of ionic liquids.

Kingston, H.M. and Walter, P. J. (1992). Comparison of microwave versus conventional dissolution for environmental applications. Spectroscopy 7 20-25. 

A nnmber of phenolic snbstances were identified by Sterbova et al. [363] in different plants by a BDS C18 colnmns with 3 pm particle size, and a comparison was carried out on different extraction methods, by the comparison of microwave-assisted extraction (MAE) to the traditional approach. 

Additional spectroscopic data were available, which have, however, less frequently been used for comparison with theoretical calculations. These comprise the UV spectrum. Ref. 20, and the microwave spectrum of 4 (a) R. D. Brown, P. D. Godfrey, and M. J. Rodler, J. Am. Chem. Soc. 1986, 108, 1296. The dipolar C NMR spectrum of 1,2-[ C]2-4 in an argon matrix was measured and analyzed in order to determine the C=C distance., cf. Ref. 24. A detailed comparison of measured and calculated chemical shifts is given in (b) H. Jiao, P. v. R. Schleyer, B. R. Beno, K. N. Houk, and R. Warmuth, Angew. Chem. 1997, 109, 2929 Angew. Chem. Int. Ed. Engl. 1997, 36, 2761. 

Table 8.3 Direct comparison of thermal and microwave results - indole library...

Recent reports of spin-rotation constants for aluminum chloride (35) and aluminum isocyanide (36) have made possible the comparison of experimental and ab initio calculated shielding results. If one were able to measure the27A1 chemical shift of one or both these compounds, it would be possible, in principle, to establish an absolute shielding scale for aluminum however, the high reactivity of these compounds has so farprecludedsuchmeasurements. High-resolution microwave measurements have also been recently carried out on A1H (37) however, analysis of the data did not consider the 27A1 spin-rotation interaction (vide infra). 

Werner, M., von Wasielewski, R., and Georgii, A. 1991. Immunodetection of a tumor associated antigen (TAG-12) Comparison of microwave accelerated and conventional method. Biotech. Histochem. 7 79 81. 

Gulmini, M., Ostacoli, G., Zelano, V and Torazzo, A. (1994) Comparison between microwave and conventional heating procedures in Tessier s extractions of calcium, copper, iron and manganese in a lagoon sediment. Analyst, 119, 2075-2080. 

Niemela, M., H. Kola, P. Peramaki, J. Piispanen, and J. Poikolainen. 2005. Comparison of microwave-assisted digestion methods and selection of internal standards for the determination of Rh, Pd and Pt in dust samples by ICP-MS. Microchim. Acta 150 211-217. 

Scheme 22 Microwave-promoted Suzuki and Heck couplings for comparison of batch and stop flow techniques...

Other potential concerns involve the two frequency references used in the experiment - the proton precession frequency forming the basis of the magnetic field determination, and the Loran-C 10 MHz frequency reference used for the NMR and microwave frequency synthesizers. The Loran-C standard is based on hyper-fine transitions in Cs with Wf=0, and so is insensitive to any preferred spatial orientation, and would not introduce a signature for Lorentz violation into the spectroscopic measurements. Bounds on clock comparisons of 199Hg and 133Cs [7,8] place crude limits on the Lorentz violating energy shifts in the precession frequency of a proton of 10-27 GeV, which imply the NMR measurements are free of shifts well below the Hz level. 

Kosar, M., Ozek, T., Goger, F., Kurkcuoglu, M. and Baser, K.H.C. (2005) Comparison of microwave assisted hydrodistillation and hydrodistillation methods for the analysis of volatile secondary metabolites. Pharmaceutical Biology 43(6), 491-495. 

G. Schnitzer, A. Soubelet, C. Testu, C. Chafey, Comparison of open and closed focussed microwave digestions in view of total mercury determination by cold vapor atomic absorption spectrometry, Mikrochim. Acta, 119 (1995), 199-209. 

V. E. Negretti de Bratter, P. Bratter, A. Reinicke, G. Schulz, W. O. L. Alvarez, N. Alvarez, Determination of mineral and trace elements in total diet by inductively coupled plasma atomic emission spectrometry comparison of microwave-based digestion and pressurized ashing systems using different acid mixtures, J. Anal. Atom. Spectrom., 10 (1995), 487-491. 

R. Saraswati, T. W. Vetter, R. L. Watters, Jr, Comparison of reflux and microwave oven digestion for the determination of arsenic and selenium in sludge reference materials using flow-injection and atomic absorption spectrometry, Analyst, 120 (1995), 95-99. 

Figure 1. Comparison of conventional and microwave on average moisture content.

Alvarado, J., Leon, L.E., Lopez, F., Lima, C. Comparison of conventional and microwave wet acid digestion procedures for the determination of iron, nickel and vanadium in coal by electrothermal atomization atomic absorption spectrometry. J. Anal. At. Spectrom. 3, 135-138 (1988)... 

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