Microscale analysis techniques

1 Scanning Electron Microscopy (SEM) and Optical Microscopy In addition to TEM, other types of microscopy can provide details of polymer nanocomposite morphology. With SEM and optical microscopy, the analysis 

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Electrokinetic phenomena is no longer merely a laboratory curiosity. It is a key component of present-day microscale analysis. Looking toward the future, it may well be that some of the current techniques will be supplemented by nanotechnology approaches, but fluid control and ion movement will likely still involve electric fields. This book will afford the reader an appreciation of the power of electrokinetic phenomena. I congratulate the editors on the breadth of coverage and the timeliness of the topic. 

Precise characterization of organic substances became possible for the Erst time as a result of elementary analysis techniques developed by Berzelius, Liebig. Dumas, Kjeldahl, and many others. The fundamental principle, which relies essentially on combustion of the material under investigation with subsequent determination of the combustion products, was adapted to microscale analysis by F. Pregl and later developed by other analysts to such a point that microelementary analysis now requires only a few milligrams of sample. This has led not only to shorter analysis times, but also the possibility of analyzing extremely small amounts of valuable natural substances. 

Figure 15.3 shows the results of the second SEM analysis designed to give a qualitative determination of the depth of fluorination. A carefully prepared cross section of the O-ring was analyzed using the so-called mapping technique. The light streak across Picture 3.2 shows where the fluorine is concentrated. With the aid of the microscale shown it can be estimated that the fluorination is approximately 5 pm deep. 

LA-ICP mass spectrometry is becoming the method of the choice for trace and isotope analysis of solid samples and is already the most important laser induced technique in inorganic mass spectrometry due to the advantage of direct solid sampling by focused laser irradiation on the sample surface and its ability to provide microscale information. 

Carbon-14 content is measured by specially designed gas proportional counters (7. Aerosol samples are first converted to CO2 by combustion in a macroscale version of the thermal evolution technique. A clam shell oven was used to heat the sample for sequential evolution of organic and elemental carbon under equivalent conditions. Due to the possibility of thermal gradients, conditions in the macroscale apparatus were adjusted to produce the same recoveries of total carbon (yg C per cm of filter area) as for the microscale apparatus. Carbon-14 data are reported as % contemporary carbon based on the 1978 1 C02 content in the atmosphere. Aldehyde data referred to in this paper were obtained by impinger sampling in dinitrophenylhydrazine/acetonitrile solution and analysis of the derivatives by HPLC with UV detection (12). Olefin measurements were made by a specially designed ozone-chemiluminescence apparatus (13) difficulties in calibration accuracy and background drift with temperature limit its use to inferences of relative reactive hydrocarbon levels. 

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