All
Low Temperature Analysis of Kaolin Clay Using Diffuse Reflectance
September 1st 2012Clays, like kaolinite and smectite, are hygroscopic and it is well known that the adsorbed water can be driven off at elevated temperatures. At very low temperatures, in addition to the typical band narrowing and shifting, changes in the O-H bond vibrational modes of clays have also been observed.
Determination of the Degree of Cure of a Varnish
September 1st 2012Modern paints and varnishes are complex mixtures and the organization of the material properties is an important task. One of the most essential variables is the curing which should in most cases take place in a reasonably short time span that can range from a fraction of a second to many days. It is difficult to evaluate the degree of curing and its completeness by visual inspection.
3D and Topographic Raman Imaging of Drug Delivery Systems
September 1st 2012Knowledge about the morphology and chemical composition of heterogeneous materials on a submicrometer scale is crucial for the development of new material properties for highly specified drug delivery systems. WITec's ultrasensitive and modular alpha300 and alpha500 microscope series allow for the analysis of the chemical characteristics of a sample three-dimensionally, underneath and at the surface. Confocal Raman microscopy for 3D chemical imaging and TrueSurface Microscopy employed for topographic Raman imaging deliver the highest spectral quality and unmatched spatial resolution.
The Orbis Micro-XRF Analyzer Series
February 1st 2012Building on more than 10 years of Micro-XRF experience, the Orbis spectrometer yields a system with excellent Micro-XRF capability while setting a new standard in analytical flexibility. The Orbis incorporates a unique motorized turret integrating video and X-ray optics allowing coaxial sample view and X-ray analysis. The turret can accommodate two additional collimators along with the X-ray optic for a total of three X-ray beam sizes to expand the Orbis analytical capabilities beyond traditional Micro-XRF analysis. Primary beam filters can be used with all spot sizes available on the turret to allow true XRF analytical capabilities in a micro-spot analysis. The working distance is increased to allow analysis over rougher sample topography without sacrificing signal intensity.
Benchtop WDXRF for Cement Analysis
February 1st 2012Cement is one of the most important materials in the construction industry. Traditionally, WDXRF spectrometers used in cement plants have been large, floor-standing models with substantial installation requirements and ownership expenses. This application note demonstrates the capabilities of the Rigaku Supermini - a new low-cost, benchtop wavelength dispersive X-ray fluorescence (WDXRF) spectrometer - for the rapid quantitative elemental analysis of cement raw meal.
Revisiting IR Transmission Sampling of Polymers
February 1st 2012Infrared (IR) sampling techniques of attenuated total reflectance (ATR) and transmission for polymer analysis are compared and contrasted. Using a real-world application, IR analysis of silane-grafted linear low density polyethylene (LLDPE) pellets is presented to illustrate the benefit of IR film transmission sampling.
Automated Circular Dichroism: A Powerful Tool for the Optimization of Protein Formulation
February 1st 2012The polyclonal IgG in this study is more thermally stable at neutral pH, (4.8 to 7.8) than it is at lower pH. The loss of thermal stability at lower pH is concomitant with a change in the pre-transition folded structure of the protein.
Handheld FTIR Analysis for the Conservation and Restoration of Fine Art and Historical Objects
February 1st 2012FTIR spectroscopy has long been used for the analysis of art and historical objects in support of efforts to conserve, restore, and validate authenticity of these rare objects. The value of the technique for this application lies in its inherent sensitivity, specificity, and non-destructive capabilities.
Cost-Effective Analysis of Major, Minor, and Trace Elements in Foodstuffs Usint the 4100 MP-AES
February 1st 2012Whether the goal is food safety, ensuring quality, or establishing provenance, measuring the trace element content of foods and beverages that we all consume is of paramount importance. While some elements are essential for our well being at low concentrations, others like lead and chromium are highly toxic and more still are being linked to viral, neurological, and other diseases. Food scares related to contamination or poor quality not only constitute a health risk, they also undermine consumer confidence. This can lead to lost earnings through reduced sales and loss of credibility through adverse publicity.
FTIR Sampling of Eye Drops Using Multiple Reflection Diamond ATR
February 1st 2012Multiple reflection ATR is ideal for detecting miniscule levels of components in solutions, both aqueous and non-aqueous. Most multiple ATR accessories use ATR crystals which are susceptible to wear and damage. Diamond, although an excellent choice due to its refractive index, high degree of chemical inertness, and low coefficient of friction, is generally not used because of its expense and its strong lattice bands around 2200 cm-1.
3D Confocal Raman Imaging in Semiconductor Research
February 1st 2012The exacting standards of quality and reliability of structured substrates in the semiconductor industry require in-depth knowledge concerning the interior structure of the devices. In this application note we present results of 3D confocal Raman imaging measurements for such characterizations.
IC–ICP–MS Speciation Analysis of As in Apple Juice
February 1st 2012In this study, apple juice samples are analyzed by IC–ICP–MS to determine the concentration of six arsenic species: the two inorganic, and highly toxic, species (As (V) and As [III]) and four organic species (arsenobetaine [AsB], arsenocholine [AsC], monomethylarsonic acid [MMA], and dimethylarsinic acid [DMA]).
Microwave Digestion of Pharmaceutical Finished Products and Ingredients for Upcoming USP Method 233
February 1st 2012Current USP Method 231 "Heavy Metals" was introduced in 1905 for determining heavy metal impurities in pharmaceutical drug products. The procedures of the method have several limitations, which produce results that are nondiscriminatory, difficult to reproduce, and qualitative, or at best, semi-quantitative.
Fast Quality Evaluation of Bulk Polymers and Products Using FT-NIR Spectroscopy
September 1st 2011FT-NIR spectroscopy for the quantitative determination of key physical parameters in bulk polymers and products, including density and melt index (MI). These measurements can often be made with little or no sample preparation.
Comparison of Secondary Structures of Similar Proteins Using Automated CD
September 1st 2011In this study, far-UV CD spectra of eight different mammalian serum albumins were measured repeatedly using automated CD spectroscopy. Two independent methods of normalizing the CD data were used to eliminate the need for accurate knowledge of protein concentration or extinction coefficient. The normalized far-UV data, representative of secondary structure, were compared to determine if there were statistically significant differences between samples. The two normalization methods agreed in every case, increasing confidence in the results.
Sample Preparation for NIR Analysis
September 1st 2011A much discussed issue related to near infrared analysis (NIR) is the necessity of sample preparation. Ground and unground samples of wheat were analyzed to determine how truly necessary it is to homogenize samples before NIR analysis. The new Retsch TWISTER mill, specifically designed for NIR sample preparation, was utilized for this comparative study.
Raman Analysis of Si Crystallinity
September 1st 2011While crystalline silicon (c-Si) is still the material of choice for modern solar cell manufacturing, the drive toward lower cost, more efficient solar cells is prompting a renewed interest in thin-film amorphous silicon (a-Si). In light of this, it is more important than ever to have the ability to quickly identify Si crystallinity, both qualitatively and quantitatively. In this application note, we evaluate how a portable Raman spectrometer can be used in conjunction with a portable video microscope to measure crystallinity.