Acid purification by subboiling
Table of Contents
Especially in ultra-trace analysis, the purity of the acids is of great importance. In principle, liquid reagents are commercially available in various and sufficient degrees of purity. However, acids of very high purity are also correspondingly expensive. Alternatively, acids can also be purified by distillation using subboiling for trace analysis. Since the equipment is made of plastic, it can also be used for the purification of hydrofluoric acid. The heating is carried out contact-free by an infrared lamp, the power of which is adjusted a way that even without additional temperature control a maximum temperature of approximately 10°C-20°C below the boiling point of the respective acid is reached. Starting from commercial quality p.a. (for analysis), purity grades in the sub-ppb range are already achieved by simple acid distillation. Further purification of the acids is possible by multiple distillation.
Advantages:
-
Can be used for HNO3, HCl, HF and H2O;
- Reduces costs for higher purity chemicals;
- Required purity levels always available fresh;
- Contaminated acid batches can be cleaned
