Complementary technique

When HPLC is used in conjunction with other techniques such as MS and IR spectroscopy then identification and quantitation of polymer additives becomes more certain. 

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Two different mixtures of peptides and alkaloids (qv) have been analy2ed by ce/uv/ms using sims to determine whether this technique can detect trace impurities in mixtures (85). The first mixture consisted of two bioactive peptide analogues, which included Lys-bradykinin (kahidin) and Met-Lys-bradykinin. The presence of 0.1% Lys-bradykinin was detected by sim ce/ms but not by ce/uv at 0.1% level as it migrated from the capillary column prior to the main component, Met-Lys-bradykinin. The second mixture consisted of two antibacterial alkaloids, berberine and palmitine. The presence of 0.15% palmitine was detected by ce/uv and sim ce/ms at 0.15% level as it migrated from the capillary column, following the main component berberine. This technique can provide a complementary technique for trace components in such sample mixtures. 

Light Scattering by Liquid Surfaces and Complementary Techniques, edited by Dominique Langevin... 

The emphasis in prior chapters has been on those aspects of reaction mechanisms that follow directly from the kinetics. No account of mechanisms is complete, however, without reference to complementary techniques. These approaches are less rigorous than kinetics per se, but nonetheless very valuable in leading one to an understanding of how chemical reactions occur. 

These include cold drawn, high pressure oriented chain-extended, solid slate extruded, die-drawn, and injection moulded polymers. Correlation of hardness to macroscopic properties is also examined. In summary, microhardness is shown to be a useful complementary technique of polymer characterization providing information on microscopic mechanical properties. 

It is worth noting that the use of polymer-supported scavengers offers a perfectly complementary technique to the use of PSRs, and in several cases the two have been successfully employed together [3,9]. 

The conservation of cultural heritage is a particular field where the use of nondestructive characterization methods is mandatory, considering the uniqueness of the objects under study. Even in cases where sampling of tiny volumes is allowed, non-destructive testing offers the possibility of applying complementary techniques to obtain more information on one specific sample. In this section we focus on the application of the described profiling technique to study paintings. The... 

Traditional electrophoresis and capillary electrophoresis are competitive techniques as both can be used for the analysis of similar types of samples. On the other hand, whereas HPLC and GC are complementary techniques since they are generally applicable to different sample types, HPLC and CE are more competitive with each other since they are applicable to many of the same types of samples. Yet, they exhibit different selec-tivities and thus are very suitable for cross-validation studies. CE is well suited for analysis of both polar and nonpolar compounds, i.e. water-soluble and water-insoluble compounds. CE may separate compounds that have been traditionally difficult to handle by HPLC (e.g. polar substances, large molecules, limited size samples). 

CE and IC are complementary techniques and their use in tandem is advantageous [886]. The determination... 

GDS instruments are viable alternatives to the traditional arc and spark-source spectroscopies for bulk metals analysis. Advantages of GDS over surface analysis methods such as AES, XPS and SIMS are that an ultrahigh vacuum is not needed and the sputtering rate is relatively high. In surface analysis, GD-OES, AES, XPS and SIMS will remain complementary techniques. GD-OES analysis is faster than AES (typically 10 s vs. 15 min). GD-OES is also 100 times more sensitive than... 

PIGE is a rapid, non-destructive technique that is employed in the analysis of light elements such as lithium (10-100 ppm limit of detection), boron (500-1000 ppm limit of detection), and fluorine (1-10 ppm limit of detection), which are often difficult to determine by other analytical means. Because the technique is based upon specific nuclear reactions, the sensitivity of PIGE varies greatly from isotope to isotope, and this non-uniformity of sensitivity has limited its widespread use as a complementary technique to micro-PIXE. 

In accord with the fact that XPS has become a standard surface science technique but has not been appreciated adequately in electrochemistry, it is the scope of this review chapter to bring XPS nearer to those who work on electrochemical problems and convince electrochemists to use XPS as a complementary technique. It is not the intention to treat fundamental physical and experimental aspects of photoelectron spectroscopies in detail. There are several review articles in the literature treating the basics and new developments in an extensive and competent way [9,13], In this article basic aspects are only addressed in so far as they are necessary to understand and... 

Turning now to the chapters in this volume, a variety of complementary techniques and approaches have been used to characterize peptide and protein unfolding induced by temperature, pressure, and solvent. Our goal has been to assemble these complementary views within a single volume in order to develop a more complete picture of denatured peptides and proteins. The unifying observation in common to all chapters is the detection of preferred backbone conformations in experimentally accessible unfolded states. 

Nemeth-Cawley, J.F., Tangarone, B.S., Rouse, J.C. (2003). Top Down characterization is a complementary technique to peptide sequencing for identifying protein species in complex mixtures. J. Proteome Res. 2, 495-505. 

The biaxial orientation in photoaddressable azobenzene films has been observed recently by polarized Raman spectromicroscopy [64]. Here, IR spectroscopy has been advantageously used as a complementary technique to measure the order... 

A. Heginbotham, V. Millay, M. Quick, The use of immunofluorescence microscopy (IFM) and enzyme linked immunosorbent assay (ELISA) as complementary techniques for protein identi fication in artists materials, J. Am. Inst. Cons., 45, 89 105 (2006). 

In addition to GC/MS, high performance liquid chromatography (HPLC/MS) has been used to analyse natural resins in ancient samples, particularly for paint varnishes containing mastic and dammar resins [34]. A partial limitation of chromatographic techniques is that they do not permit the analysis of the polymeric fraction or insoluble fraction that may be present in the native resins or formed in the course of ageing. Techniques based on the direct introduction of the sample in the mass spectrometer such as direct temperature resolved mass spectrometry (DTMS), direct exposure mass spectrometry (DE-MS) and direct inlet mass spectrometry (DI-MS), and on analytical pyrolysis (Py-GC/MS), have been employed as complementary techniques to obtain preliminary information on the... 

Most chemists tend to think of infrared (IR) spectroscopy as the only form of vibrational analysis for a molecular entity. In this framework, IR is typically used as an identification assay for various intermediates and final bulk drug products, and also as a quantitative technique for solution-phase studies. Full vibrational analysis of a molecule must also include Raman spectroscopy. Although IR and Raman spectroscopy are complementary techniques, widespread use of the Raman technique in pharmaceutical investigations has been limited. Before the advent of Fourier transform techniques and lasers, experimental difficulties limited the use of Raman spectroscopy. Over the last 20 years a renaissance of the Raman technique has been seen, however, due mainly to instrumentation development. 

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