Sample types
The IR microscope can record spectra from a range of samples from thin microtomed sections to polished blocks and embedded particles. The nature of the sample generally determines the sampling configuration required (Transmission, ATR etc.). Some examples of samples, with details of preparation requirements, are given below:

Transmission

• Biological tissues – microtomed to a thickness of 5 to 10 microns and mounted on an IR transmitting window such as CaF₂, BaF₂ or ZnSe.
• Cultured cells – grown on a substrate such as CaF₂ or silicon nitride windows, and freeze-dried or fixed and air dried.
• Polymer multilayers – microtomed to a thickness of 5 to 10 microns and placed in a compression cell between two windows of CaF₂ or diamond.

Reflectance

• Minerals, finely polished with alumina or diamond to a surface roughness of 1 micron or less.
• Biological tissues or cultured cells mounted or grown on reflective surfaces such as Mirr-IR microscope slides (Kevley technologies, Ohio) or gold coated glass. This type of measurement if often referred to as “transflectance”.

Grazing incidence

• Thin (sub micron) coatings on metallic or other highly IR-reflective surfaces.
• Corrosion products on metallic surfaces.
• Samples must be optically flat to the infrared beam.
• Ideally an uncoated/untreated area should be left on the sample surface for recording the reference spectrum.

ATR

• Hard materials such as paints, minerals or bone, that cannot be microtomed for transmission measurements. These must be polished to a surface roughness of around 1 micron or better.
• Paint multilayers embedded in resin and polished with alumina or diamond paste to provide a flat contact surface. Alternatively a microtome can be used to provide a flat surface.
• Fibrous materials such as paper.
• Inks or pigments on rough surfaces such as paper

Sample stages
The microscope is equipped with a motorised sample stage and can accommodate samples up to approximately 10×10 cm in size. Maximum sample thickness is restricted to 10 mm by the vertical travel limits of the stage and the working distance of the objective optic. The microscope stage is fitted with interchangeable plates which are adapted for different sample shapes and sizes. Typical sample sizes that can be accommodated within these plates include:

• 13 mm diameter windows (transmission).
• 25 × 76 mm microscope slides (reflectance).
• 50 × 76 mm sample chambers (e.g. sample compression cell).

• The IR microscope beamline is not yet equipped with sample heating or cooling facilities. Users potentially requiring such facilities in future should contact the IR beamline staff to discuss their requirements.
• Liquid handling cells, for the study of live biological samples, are currently under development. Users should contact beamline staff to discuss possible use of this equipment.

Preparation facilities
Limited space is available in and outside of the IR Hutch for sample preparation. The Synchrotron has both a Chemistry and a Biochemistry Laboratory on-site. These laboratories are equipped with fume cupboards, fridges, freezers, stereo microscope with camera, UV-Vis spectrometer and balances. Please consult IR Beamline staff if you require specific equipment for sample preparation (you may have to supply your own equipment).

A Class II biological containment laboratory is available for use during your beamtime if required. This contains Class II safety cabinet, CO2 incubator, inverted microscope, centrifuges, fridge, freezer and water bath. Users requiring access to this facility should contact the IR beamline staff when submitting a proposal which involves the handling of live biological material.

Transport and safety
Please see Sample Transport & Safety for more specific information.
Please consult your OHSE if unsure how to best transport your samples. If you have air- or moisture-sensitive materials, it is recommended you transport samples in a sealed box supplied with desiccant. An electric desiccator (10% humidity) is available in the IR Hutch to store your samples if necessary.

Waste disposal
Please see Waste Disposal for more specific information.
You must remove all waste from the beamline for disposal at your own facility. Some waste disposal facilities are available in the Chemistry and Biochemistry Laboratories. Please consult IR Beamline staff for more information.