Solids direct analysis

In electrogravimetry the analyte is deposited as a solid film on one electrode in an electrochemical cell. The oxidation of Pb +, and its deposition as Pb02 on a Pt anode is one example of electrogravimetry. Reduction also may be used in electrogravimetry. The electrodeposition of Cu on a Pt cathode, for example, provides a direct analysis for Cu +. 

For solids, there is now a very wide range of inlet and ionization opportunities, so most types of solids can be examined, either neat or in solution. However, the inlet/ionization methods are often not simply interchangeable, even if they use the same mass analyzer. Thus a direct-insertion probe will normally be used with El or Cl (and desorption chemical ionization, DCl) methods of ionization. An LC is used with ES or APCI for solutions, and nebulizers can be used with plasma torches for other solutions. MALDI or laser ablation are used for direct analysis of solids. 

ICP-OES is one of the most successful multielement analysis techniques for materials characterization. While precision and interference effects are generally best when solutions are analyzed, a number of techniques allow the direct analysis of solids. The strengths of ICP-OES include speed, relatively small interference effects, low detection limits, and applicability to a wide variety of materials. Improvements are expected in sample-introduction techniques, spectrometers that detect simultaneously the entire ultraviolet—visible spectrum with high resolution, and in the development of intelligent instruments to further improve analysis reliability. ICPMS vigorously competes with ICP-OES, particularly when low detection limits are required. 

Kurfurst U (1998) Solid Sample Analysis - Direct and Slurry Sampling using GF-AAS and ETV-ICP. Springer, Berlin, Heidelberg, New York. 

Nowka R, Muller H (1997) Direct analysis of solid samples by graphite furnace atomic absorption spectrometry with a transversely heated graphite atomizer and D2-background correction system (SS GF-AAS). Fresenius J Anal Chem 359 132-137. 

A suitable method to determine the degree of homogeneity of an element in a material is by repetitive analysis of a large number of small soUd ahquots by direct solid sample analysis. As shown in Figure 4.3, there is a functional relationship between the sample mass used for analysis and the standard deviation of repetitive analysis. 

Noweoy R, Marr IL, Ansari TM, Muller H 1999) Direct analysis of solid samples by GFAAS -determination of trace hea-vy metals in barytes. Fresenius ( Anal Chem 364 533-540. 

ScHRON W, Liebmann A, Nimmereall G 2000) Direct solid sample analysis of sediment, soils, rocks and advanced ceramics by ETV-ICP-AES and GF-AAS. Fresenius J Anal Chem 366 79-88. 

Beef kidney samples were analyzed for atrazine by dispersing 0.5-g portions of kidney with 2-g portions of XAD-7 HP resin for matrix solid-phase dispersion. " By using a mortar and pestle, a powder-like mixture was prepared that was subjected to subcritical extraction using ethanol-modified water at 100 °C and 50 atm. The ethanol-water extract was sampled using a CW-DVB SPME fiber for direct analysis using ion-trap GC/MS, and the recoveries were quantitative for atrazine at the 0.2 mg kg fortification level. 

None of the above-mentioned ICPMS techniques can rival MC-TIMS and MC-ICPMS in terms of analytical precision, but the advantage of conventional ICPMS lies in the speed and ease with which data can be acquired. Analysis times are typically less than 10 minutes, and results can be obtained on solid, liquid or gas samples directly, without chemical preparation. Direct analysis will, however, give rise to high levels of molecular... 

Selection of a suitable ionisation method is important in the success of mixture analysis by MS/MS, as clearly shown by Chen and Her [23]. Ideally, only molecular ions should be produced for each of the compounds in the mixture. For this reason, the softest ionisation technique is often the best choice in the analysis of mixtures with MS/MS. In addition to softness , selectivity is an important factor in the selection of the ionisation technique. In polymer/additive analysis it is better to choose an ionisation technique which responds preferentially to the analytes over the matrix, because the polymer extract often consists of additives as well as a low-MW polymer matrix (oligomers). Few other reports deal with direct tandem MS analysis of extracts of polymer samples [229,231,232], DCI-MS/MS (B/E linked scan with CID) was used for direct analysis of polymer extracts and solids [69]. In comparison with FAB-MS, much less fragmentation was observed with DCI using NH3 as a reagent gas. The softness and lack of matrix effect make ammonia DCI a better ionisation technique than FAB for the analysis of additives directly from the extracts. Most likely due to higher collision energy, product ion mass spectra acquired with a double-focusing mass spectrometer provided more structural information than the spectra obtained with a triple quadrupole mass spectrometer. 

Direct solid-state polymer/additive mass analysis has involved various ionisation modes El (Section 6.2.1), Cl (Section 6.2.2), DCI (Section 6.2.2.1), FAB (Section 6.2.4), FI (Section 6.2.5), FD (Section 6.2.6) and LD. Survey mass spectra obtained with soft ionisation methods (FI-MS, CI-MS) provide diagnostic overviews of chemical composition. The supplemental tandem (MS/MS) and atomic composition (AC-MS) techniques are used to make specific identifications of various organic ingredients. Direct analysis of polymer systems for more than a few thousand daltons has only just begun. Ionisation methods employed are FD, ESI and MALDI. Solid-probe ToF-MS (or DI-HRMS) is a breakthrough [188]. 

Direct solid sample analysis is still mostly a subsidiary method, confined to specific analytical tasks, rather than truly complementary to traditional analysis via solutions. Solid sampling is not standard in routine... 

TXRF is most applicable to liquid samples, but success has also been achieved with direct analysis of some solids, e.g. very thin sections of organic tissue and polymer film. Alternatively, small amounts of solid material can be analysed by TXRF after acid digestion. 

Dehydrochlorination of a 1-chlorosilanamine by vacuum gas solid reaction (VGSR). The presence of the iminosilane was confirmed by direct analysis of the gaseous flow.7... 

Nimmerfall G, Schron W (2001) Direct solid sample analysis of geological samples with SS-GF-AAS and use of 3D calibration. Fresenius J Anal Chem 370 760... 

DGE a AC AMS APCI API AP-MALDI APPI ASAP BIRD c CAD CE CF CF-FAB Cl CID cw CZE Da DAPCI DART DC DE DESI DIOS DTIMS EC ECD El ELDI EM ESI ETD eV f FAB FAIMS FD FI FT FTICR two-dimensional gel electrophoresis atto, 10 18 alternating current accelerator mass spectrometry atmospheric pressure chemical ionization atmospheric pressure ionization atmospheric pressure matrix-assisted laser desorption/ionization atmospheric pressure photoionization atmospheric-pressure solids analysis probe blackbody infrared radiative dissociation centi, 10-2 collision-activated dissociation capillary electrophoresis continuous flow continuous flow fast atom bombardment chemical ionization collision-induced dissociation continuous wave capillary zone electrophoresis dalton desorption atmospheric pressure chemical ionization direct analysis in real time direct current delayed extraction desorption electrospray ionization desorption/ionization on silicon drift tube ion mobility spectrometry electrochromatography electron capture dissociation electron ionization electrospray-assisted laser desorption/ionization electron multiplier electrospray ionization electron transfer dissociation electron volt femto, 1CT15 fast atom bombardment field asymmetric waveform ion mobility spectrometry field desorption field ionization Fourier transform Fourier transform ion cyclotron resonance... 

Direct analysis 7.1 XRD, XRF, infrared spectroscopy (NIR and MIR), solid-state nuclear magnetic resonance (NMR), advanced spectroscopy using synchrotron radiation, neutron activation, fluorescence, and visible and electron microscopy... 

The purpose of this review is two pronged. We have discussed the far-reaching manifestations of molecular chirality in crystals on the macroscopic scale, and have described the various direct methods for the assignment of absolute configuration of chiral molecules in solids. Our analysis has been confined to the solid state, because of the difficulties associated with the direct assignment of absolute configuration in the dispersed phase (12). 

API offers unique opportunities for the implementation of new sources or to develop new applications. Atmospheric pressure matrix assisted laser desorption (AP-MALDI) [21] can be mounted on instruments such as ion traps which were originally designed only for electrospray and LC-MS. New API desorption techniques such as desorption electrospray (DESI) [22] or direct analysis in real time (DART) [23] have been described and offer unique opportunities for the analysis of surfaces or of solid samples. 

Direct analysis of solid samples or analytes present on solid surfaces without any sample preparation has always been a topic of interest. Desorption electrospray ionization (DESI) is an atmospheric pressure desorption ionization method introduced by Cooks et al., producing ions directly from the surface to be analyzed, which are then sampled with the mass spectrometer [22, 37]. DESI is based on charged liquid droplets that are directed by a high velocity gas jet (in the order of 300 m s ) to the surface to be analyzed. Analytes are desorbed from the surface and analyzed by mass spectrometer (Eig. 1.15). 

Surface enhanced laser desorption/ionization (SELDI) is a distinctive form of laser desorption ionization where the target plays an active role in the sample preparation procedure and ionization process [49]. Depending on the chemical or biochemical treatment, the SELDI surface acts as solid phase extraction or an affinity probe. Chromatographic surface is used for sample fractionation and purification of biological samples prior to direct analysis by laser desorption/ ionization. SELDI is mainly applied for protein profiling and in biomarker discovery by comparing protein profiles from control and patient groups. 

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