The term "MQ water" typically refers to Milli-Q® water, which is a brand name synonymous with ultrapure water. It doesn't stand for anything specific beyond being a brand name.
Understanding Milli-Q® Water
Milli-Q® water is produced using a water purification system manufactured by MilliporeSigma (formerly Millipore). This system utilizes a combination of technologies to remove virtually all contaminants from water, resulting in water with a resistivity of 18.2 MΩ·cm at 25 °C and very low levels of total organic carbon (TOC).
Purification Process
The Milli-Q® water purification process typically involves several steps:
- Pre-treatment: This might include filtration to remove particulate matter and activated carbon to remove chlorine and organic compounds.
- Reverse Osmosis (RO): RO removes a large percentage of dissolved ions and organic molecules.
- Ion Exchange: Ion exchange resins remove remaining ionic contaminants.
- UV Oxidation: Ultraviolet (UV) light is used to oxidize organic molecules, reducing TOC levels. The reference mentions a "long-life dual wavelength UV lamp."
- Ultrafiltration: Ultrafiltration removes pyrogens, bacteria, and particulate matter.
- Final Polishing: A polishing cartridge, such as the Quantum® cartridge mentioned in the reference, removes any remaining trace contaminants.
Applications of Milli-Q® Water
Due to its exceptional purity, Milli-Q® water is widely used in various scientific and industrial applications, including:
- Laboratory Research: Cell culture, molecular biology, analytical chemistry.
- Pharmaceuticals: Formulation of injectable solutions, cleaning of equipment.
- Electronics Manufacturing: Rinsing of semiconductor wafers.
- Other Industries: Any application requiring extremely pure water.
In summary, while you might see "MQ water" used, it's best understood as a shorthand for the brand name Milli-Q® water, which designates ultrapure water produced by a specific type of water purification system. It is not an acronym with a direct expansion of those letters.
