Although it is possible to handle liquid microliter samples in infrared spectrographic analyses using a beam condenser, it is more expedient to avoid its use whenever possible. In the present work excellent spectra have been obtained repeatedly on 0.3 μl liquid samples. Liquids can be applied directly from the gas chromatograph onto the salt plate or transferred from traps using a syringe.
G. L. K. Hunter, "Modified Infrared Salt Plate for Liquid Microliter Samples Without Beam Condenser," Appl. Spectrosc. 18, 159-159 (1964)