Laboratory Principles and Water Types in Laboratory

Haematology and Chemistry Laboratory Principles

Section B: Laboratory Principles

1.1 Water in Laboratory

Water serves as a fundamental component in laboratory settings, particularly in biochemical experiments. The purity of water has a significant impact on the accuracy and reliability of experimental outcomes. This is because any impurities present in water can interfere with chemical reactions and thus adversely affect analytical results.

Types of Water Used in Laboratory

Several types of water are utilized in laboratory procedures, each with different purification methods to ensure its suitability for various experiments. The types of water commonly used include:

  1. Feed Water / Tap Water: This is the water that comes directly from municipal sources and is generally not suitable for laboratory experiments due to its impurities.

  2. Pyrogen-Free Water: This type of water is treated to remove pyrogens (substances that can cause fever when introduced into the body). It can be obtained through processes such as autoclaving and ultraviolet (UV) radiation, effectively sterilizing the water for certain laboratory applications.

  3. Grade 3 Water (Distilled Water): This water is produced via a single distillation process. While it is purer than tap water, it still contains some levels of impurities, making it appropriate for certain laboratory uses but not for highly sensitive biochemical analyses.

  4. Grade 2 Water (Deionized / Double Distilled Water): This is obtained through double distillation or deionization, providing a higher level of purification than Grade 3 water, making it suitable for a wider range of laboratory applications.

  5. Grade 1 Water (Ultra Pure Water): This is the highest quality of water available for laboratory use. It is obtained through multiple purification methods, including filtration, deionization, and other advanced techniques, ensuring the removal of nearly all contaminants. This type of water is critical for extremely sensitive experiments such as those conducted in molecular biology or analytical chemistry where the highest degree of purity is required.