International
Tables for Crystallography Volume F Crystallography of biological macromolecules Edited by M. G. Rossmann and E. Arnold © International Union of Crystallography 2006 |
International Tables for Crystallography (2006). Vol. F. ch. 5.2, p. 119
Section 5.2.6.2. Volumenometry
a
Molecular Biology Consortium, Argonne, Illinois 60439, USA |
This technique measures the increase in gas pressure due to changes in the volume of a calibrated container into which the crystal, having previously been weighed, is introduced (Reilly & Rae, 1954). Almost any gas can be used for this technique if it is compatible with the apparatus and does not interact with the crystal. The empty, calibrated chamber is pressurized by adding a measured gas bolus, and this pressure is measured. After it is weighed, the crystal sample is placed in the container, which is repressurized by adding the same volume of gas. The difference in pressures between the two measurements is due to the change in volume of the container due to the crystal's presence. In principle, this method is compatible with powdered crystal samples, multiple crystals, or irregularly shaped crystals. As with micropycnometry, this technique is not appropriate for macromolecular crystals. The crystal must be free of external solvent, yet not dried, and the microbalance must be able to measure the crystal's weight precisely and accurately. The useful lower limit of crystal size for this technique, reported by Richards & Lindley in Chapter 3.2 of IT C (2004), is 0.01 ml.
References
Reilly, J. & Rae, W. N. (1954). Determination of the densities of solids by voluminometry. In Physico-chemical methods, Vol. 1, pp. 577–608. New York: van Nostrand.Google ScholarRichards, F. M. & Lindley, P. F. (2004). Determination of the density of solids. In International tables for crystallography, Vol. C. Mathematical, physical and chemical tables, edited by E. Prince, ch. 3.2. Dordrecht: Kluwer Academic Publishers.Google Scholar