Application Notes: General

Low concentration natural methanol exists in most alcoholic beverages and usually causes no immediate health threat. Nevertheless, it is possible to have natural occurring methanol in beverages with concentration as high as 18 g/L of ethanol; or equivalent to 0.72% methanol in 40% ethanol, in alcohol (1). Current EU regulation limits naturally occurring methanol to below 10 g/L of ethanol; or equivalent to 0.4% methanol in 40% ethanol.

Whether 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.

Multiple 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.

The Optima 8x00 ICP-OES series utilizes the new Flat Plate plasma technology that replaces the traditional helical coil design used since the inception of the inductively coupled plasma. The Flat Plate plasma technology, as seen in Figure 1, utilizes two flat induction plates to produce a plasma that is compact, dense, and robust. This plasma utilizes about half the argon required by previous helical coil designs while still delivering exceptional analytical performance.

Analysis of the temperature of the photosphere and determine the temperature by students using CCD spectrometers.

In 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]).

Current 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.

Pork fat was directly analyzed in this study with Bruker's FT-NIR system for iodine value (IV) with an accuracy expressed in RMSEP of 1.1 IV.

The approach to infrared measurements of diffusely scattering materials often is dictated by the objective of the analysis. Spectral data from three different mid-infrared reflectance sampling accessories are contrasted.

In 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.

A 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.

While 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.

Recent evidence that the phthalate plasticizers may cause health problems, particularly in children, has resulted in many countries prohibiting the use of phthalates in toys and clothing. The United States Child Safety Law actually prohibits the presence of several phthalate compounds at levels exceeding 0.1 wt % even though the commercial levels are often greater than 10%. While ATR spectroscopy works well for identifying phthalates at commercial levels, a more sensitive technique is required to detect trace levels.

The Moxtek Proflux UVC266 analyzer improves UV–vis NIR spectrophotometer performance. As the analyzer polarizer, the UVC266 conserves space, offers an exceptionally wide cone acceptance angle, and has no disturbance issues as does the Glan-Taylor prism due to its air-gap.

Analyzing the effect of UV LED modules on disinfecting ballast water using UV–vis spectroscopy.

Nanoscale structures (quantum dots and quantum wires) are being studied extensively with a view to building ever more exotic devices, such as more efficient lasers and LEDs, or quantum information processing components. One type of material under investigation consists of semiconductor quantum wires based on InAs.

Low concentration natural methanol exists in most alcoholic beverages and usually causes no immediate health threat. Nevertheless, it is possible to have natural occurring methanol in beverages with concentration as high as 18 grams per liter of ethanol; or equivalent to 0.72% methanol in 40% ethanol, in alcohol (1). Current EU regulation limits naturally occurring methanol to below 10 grams per liter of ethanol; or equivalent to 0.4% methanol in 40% ethanol.

Increasing temperature can cause chemical changes, alter reaction rates, concentrate an aqueous sample, or evaporate a solvent. These transformations can be readily monitored by diamond ATR spectroscopy. This note explores the use of a diamond ATR to examine heat-induced changes in the clay.

True surface microscopy for topographic confocal Raman imaging adds optical profilometer functionality to a highly sensitive confocal Raman microscope. Using this profilometer function, topographic scans of several square millimeters can be acquired, similar to a very large AFM topography image. This acquired large-area topography image can be used to trace the surface contours while acquiring a confocal Raman image.

Overcoming fluorescence interference in a variety of samples is achieved by using dispersive 1064 nm Raman excitation instruments.

Building 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.

Traditionally the analysis of volatile liquids by FTIR spectroscopy has always entailed a sealed fixed pathlength cell.

Overcoming fluorescence background noise in cancerous biological tissue samples achieved by using Dispersive 1064nm Raman excitation instruments.

Low concentration natural methanol exists in most alcoholic beverages and usually causes no immediate health threat.

New detector and optical bench options make it possible to configure near-infrared spectrometer setups for high-resolution applications such as laser and optical fiber characterization.

The formal European Union analytical method to measure and regulate the concentration of selenium disulphide is by the determination of selenium via flame atomic absorption spectrometry.

Diamond is generally not used as a multiple reflection ATR element due to its strong lattice bands around 2200 cm-1M.

This study describes a new automated technique for measuring protein conformation by CD spectroscopy and how changes can be followed in different pH environments.