X-ray diffraction
X-ray diffraction is divided into two kinds of single crystal diffraction and powder diffraction, single crystal is mainly used for the determination of molecular weight and crystal structure, powder is mainly used for the identification and purity of crystalline substances.
Single crystal diffraction
Single crystal diffraction is a reliable method to confirm the polycrystalline form. This method can obtain the cell parameters of the crystal, and then determine the crystal configuration and molecular arrangement, so as to achieve a deep understanding of the crystal form. The method can also be used for the determination of crystal water/solvent and the confirmation of the bonding relationship between salt-forming drug bases and acid groups. However, because it is difficult to obtain the right size and purity of single crystals, this method has some difficulties in practical operation.
TD-5000 X-ray Single Crystal Difffractometer
Powder diffraction
Powder diffraction is the most commonly used method to study drug polymorphisms. This method does not need to prepare single crystals, which makes the experimental process more simple.The powder X-ray diffraction pattern of each crystal is like a human fingerprint, and the intensity and distribution of the diffraction line of each crystal measured by this method have special laws.
TD Series Powder Diffractometer