Principles of Raman Spectroscopy (7) Raman spectroscopy FAQ – Equipment related (3) –

July 9, 2020

Q16. What is the maximum size of the sample can be placed in the sample chamber?
Depending on the drive range of the automatic stage, the maximum dimensions are 75 mm (L) x 50 mm (W) x 30 mm (H). By removing the stage, the sample height can be increased to 80 mm (Fig. 24).

Fig. 24 Sample stage in microscopic Raman spectrophotometer

Q17. Can I heat or cool the sample?
Heating and cooling measurements can be performed using a thermo-control stage. Figure 25 shows a trehalose measurement at a constant temperature of 80 °C at one minute intervals. The mode below 500 cm-1 assigned to lattice vibrations changes over time, indicating a crystal phase transition. Detachment of bound water from the amorphous hydrated compound causes recrystallization to occur.

Fig. 25 Time-lapse change of Raman spectrum of trehalose

Q18. Can I carry the instrument to a place other than the laboratory and perform measurements?
It is possible. JASCO also offers a portable Raman spectrophotometer (RMP-500 series) . Fig. 26 shows an example of performing a nondestructive analysis of the composition of a fresco in a church.

Fig. 26 Analysis of church fresco produced in the 16th century