Question

Briefly describe two techniques for minimizing the effects of water on the FTIR spectra of proteins.

Answer 1

1. Arithmetic subtraction of water spectrum from the plasma spectra by means of computational manipulations.

2. The drying process.

The drying process is although time consuming, requires less computational manipulations and is shown to be capable of eliminating all the spectral contributions of water and maintaining a reasonable Signal-to-Noise ratio (S/N). Sample is dried for 40 minutes, a time period that permits obtaining FTIR spectrum with more spectroscopic information and enhanced S/N, whose peaks can be assigned and enabling a qualitative analysis of the sample. During acquisition, the room temperature is to be maintained at ± 23ºC and humidity to be maintained at ± 39%.