FOCAS Institute IR Request Form

Principle:

Fourier transform infrared (FT-IR) spectroscopy is a method used to obtain infrared spectra of a sample. When IR radiation is passed through a sample being examined, some radiation is absorbed by the sample and some passes through it. A signal of a spectrum for the resulting fingerprint of sample is then detected. The Fourier Transform converts the output to an interpretable spectrum and generates spectra with patterns. Its main features may be described as:

Powerful built-in data processing routines automate data analysis.  

Superb visible image quality ensures accurate and easy sample inspection.

Seamless automation simplifies set-up and measurement, increasing productivity and reducing errors.

Two in one detector enables single-point microscopy as well as IR imaging, allowing micro-contaminants in products and packaging to be identified in seconds etc.

Current model:

 

Figure: a (Perkin Elmer Spotlight 400N FT-IR Microscope) and b (steps how FTIR spectroscopy takes place in which a signal spectrum is plotted on the graph of %Transmittance vs. Wavenumber (cm-1))

See video for further information

Perkin Elmer 400 Series Spectrometer

The Perkin Elmer 400 Series Spectrometer is a dual range bench top FT-IR instrument. Its fully optimized performance is achieved by the provision of dual sources, dual beam splitters and dual detectors. It can be operated in ratio, single beam and interferogram. Its high sensitivity allows the smallest samples to be detected, while its IR imaging speed improves problem solving time as well as redefines maximum measurement areas, revealing information not previously available thus extending IR analysis to many new applications with 6.25 µm and 25 µm pixel resolution.

For MIR Configuration, the optical system enables you to collect data over a total range of 7800 to 370cm-1 with a best resolution of 0.5cm-1. It is fitted with an MCT (Mercury Cadmium Telluride) detector.

For NIR Configuration, the optical system enables you to collect data over a total range of 15000 to 1250cm-1 with a best resolution of 0.5cm-1. Deuterated Triglycine Sulphate (NIR DTGS) detector is fitted with it.

We have also an ATR imaging accessory (Germanium crystal with a refractive index of 4.0) which enables collection of ATR images from a sample area that has been visually identified using the microscope. To ensure good optical contact during data collection, the accessory includes a mechanism that applies a consistent and controllable compressive force between the sample and the ATR crystal via the anvil.

The range of measurement of the accessory allows you to collect data over a total range of 4500cm-1 – 720cm-1 (ATR Imaging Mode) with a spatial resolution of 3.1µm at the centre of field.

Technical specifications

The Near-IR spectral range is particularly convenient for rapid sample imaging. Spectra are collected directly from the sample surface at a pixel size of either 6.25 x 6.25µm or 25 x 25µm over a user-definable sampling area. Samples are simply stepped below a linear detector array, building an image at a rate of up to 80 pixels per second. For example, a 1 x 1mm sample area can be imaged in less than 1 minute at 25 x 25µm pixel size. Each pixel corresponds to high quality NIR spectrum and by using spotlight’s built-in intelligent software routines, chemical differences between pixels are highlighted images that show the distribution of individual ingredients are quickly displayed.

Typical samples:

FTIR spectroscopy is used to analyse and identify unknown samples such as films, solids, powders, liquids, fibres, polymers etc.

Applications:

Tablet stability studies, Dry powder electrostatic coating analysis, Counterfeit detection, Contamination identification, Packaging development, and Transdermal patches and related delivery systems.

Standards:

Samples can be accessed in accordance with the other standards such as: ASTM E168, ASTM E1252.