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Figure 1. The AccessATR™.
Access ATR™is an affordable single reflection, horizontal internal reflection (ATR) accessory. Its simple optical design and straightforward use make it a perfect introductory ATR accessory. The Access ATR™is excellent for repeatable qualitative and quantitative spectroscopic studies of a wide range of samples. These include aqueous and organic liquids, pastes, and organic and inorganic powders.
ATR spectroscopy is the method of choice for many samples. ATR requires little or no sample preparation and is a much quicker method for analyzing all types of samples. For affordable analysis of solids and powders, the sample is simply placed in the trough and pressed against the ATR crystal with the built-in press. No KBr pellets or nujol mulls are required. For liquids or pastes, just smear or drip a small amount of sample on the top of the ATR crystal and record the spectrum. Avoid the typical problems with transmission liquid cells - interference fringes, peak saturation, and squeezing viscous samples into short pathlengths. The Access ATR™ produces excellent spectral quality every time. Access ATR™ uses two planar mirrors to direct the beam to and from the ATR crystal at a 45° incident angle. The ATR crystal is made from ZnSe which has a wide useful spectral range (20,000 cm-1 to 550 cm-1) and durable mechanical properties. The crystal is held in place with a gasket, making it straightforward to replace the crystal when needed. This design is reasonably insensitive to precise alignment. The accessory just slides into the sample slide plate holder supplied with the FTIR spectrometer and no further alignment is necessary.
Figure 2. ATR Spectrum of a Twix Wrapper.
Figure 3. ATR Spectrum of the Twix Caramel (right).
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Figure 4. ATR Spectrum from a Twix Wafer.
Figure 5. ATR Spectrum of Rubbing Alcohol (upper) and Water (lower).
Figures 2 through 4 show spectra from different portions of a Twix™(Mars, Inc.) candy bar, illustrating its use with solids and pastes. Figure 5 shows the spectrum of two liquids, rubbing alcohol and water, clearly showing that water is one of the components of rubbing alcohol. Subtraction, using commercial spectrometer software, results in a spectrum that is clearly identifiable as isopropanol. Note that, despite the strong absorbance of these samples, the ATR spectra are free from saturation effects.
Access ATR™ offers simplicity, economy, and versatility for all FTIR laboratories, enabling quick and accurate measurements for a wide range of samples.
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