2. FTIR purge gas generator (Whatman) (see Note 2).
3. Personal computer with spectra acquisition software for collecting spectra as a function of time (see Note 3).
4. Software for spectral analysis (e.g., “Spectrum procedures”
from PerkinElmer or “Omnic” from Nicolet/Thermo Fischer)
(see Note 3).
2.2 Attenuated Total
Reflection Accessory
and Setup for Diffusion
Measurements
1. Attenuated total reflection (ATR) accessory with a diamond/
ZnSe crystal, 1 Â 1 mm (e.g., basic module from PerkinElmer,
Nicolet/Thermo Fischer, or temperature-controlled devices
from Harrick Scientific or Specac).
2. Sample mounting system for mounting tissue pieces in a holder
positioned on the ATR crystal allowing adding solution of
interest on top of the sample. Sample holder can be constructed by cutting a microtube with 1.9 cm height, 1.1 cm
diameter at the top, and a hole diameter of 5 mm at the bottom
for mounting the sample. The ATR pressure arm can be used to
keep the sample holder in position.
2.3 Attenuated Total
Reflection Accessory
and Setup
for Controlling
the Sample Humidity
1. Attenuated total reflection (ATR) accessory with a diamond/
ZnSe crystal, 1 Â 1 mm, e.g., basic modules from PerkinElmer,
Harrick Scientific, Specac, or Nicolet/Thermo Fisher.
2. Donut-shaped shallow dish with lid, which can be filled with
saturated salt solution and placed such that it surrounds the
sample holder.
3. Saturated salt solutions to create a defined relative humidity
(RH) [13]. The following solutions can be used: water (~94%
RH) and saturated solutions of NaCl (~75% RH), MgCl 2
(~33% RH), and LiCl (~13% RH). Saturated salt solutions are
prepared by adding salt to water under continuous stirring
until the salt no longer dissolves and salt crystals are visible.
4. Thermometer and hygrometer (e.g., from Fluke), for measuring the sample temperature and the relative humidity in the
sample area.
2.4 TemperatureControlled Sample
Holder for
Transmission Spectra
Acquisition
1. Temperature-controlled demountable liquid transmission cell/
sample holder with Luer lock fittings and a temperature controller for controlled heating of the device (e.g., from Harrick
Scientific). The sample holder should allow mounting of samples sandwiched between two IR transparent windows (25 mm
diameter), while the sample edge should have an access point
for a thermocouple (to accurately measure the sample temperature) or for touching the sample with a copper wire to induce
ice nucleation (see Note 4).
In situ Infrared Spectroscopy
333
3. Personal computer with spectra acquisition software for collecting spectra as a function of time (see Note 3).
4. Software for spectral analysis (e.g., “Spectrum procedures”
from PerkinElmer or “Omnic” from Nicolet/Thermo Fischer)
(see Note 3).
2.2 Attenuated Total
Reflection Accessory
and Setup for Diffusion
Measurements
1. Attenuated total reflection (ATR) accessory with a diamond/
ZnSe crystal, 1 Â 1 mm (e.g., basic module from PerkinElmer,
Nicolet/Thermo Fischer, or temperature-controlled devices
from Harrick Scientific or Specac).
2. Sample mounting system for mounting tissue pieces in a holder
positioned on the ATR crystal allowing adding solution of
interest on top of the sample. Sample holder can be constructed by cutting a microtube with 1.9 cm height, 1.1 cm
diameter at the top, and a hole diameter of 5 mm at the bottom
for mounting the sample. The ATR pressure arm can be used to
keep the sample holder in position.
2.3 Attenuated Total
Reflection Accessory
and Setup
for Controlling
the Sample Humidity
1. Attenuated total reflection (ATR) accessory with a diamond/
ZnSe crystal, 1 Â 1 mm, e.g., basic modules from PerkinElmer,
Harrick Scientific, Specac, or Nicolet/Thermo Fisher.
2. Donut-shaped shallow dish with lid, which can be filled with
saturated salt solution and placed such that it surrounds the
sample holder.
3. Saturated salt solutions to create a defined relative humidity
(RH) [13]. The following solutions can be used: water (~94%
RH) and saturated solutions of NaCl (~75% RH), MgCl 2
(~33% RH), and LiCl (~13% RH). Saturated salt solutions are
prepared by adding salt to water under continuous stirring
until the salt no longer dissolves and salt crystals are visible.
4. Thermometer and hygrometer (e.g., from Fluke), for measuring the sample temperature and the relative humidity in the
sample area.
2.4 TemperatureControlled Sample
Holder for
Transmission Spectra
Acquisition
1. Temperature-controlled demountable liquid transmission cell/
sample holder with Luer lock fittings and a temperature controller for controlled heating of the device (e.g., from Harrick
Scientific). The sample holder should allow mounting of samples sandwiched between two IR transparent windows (25 mm
diameter), while the sample edge should have an access point
for a thermocouple (to accurately measure the sample temperature) or for touching the sample with a copper wire to induce
ice nucleation (see Note 4).
In situ Infrared Spectroscopy
333