Author: Purific
Why is ultrapure water corrosive?
Ultrapure water is considered corrosive due to its extreme purity and lack of dissolved ions. Here’s why:
1. Ion Deficiency and Aggressiveness:
- Deionization: Ultrapure water has been stripped of nearly all its dissolved ions and impurities, making it highly ion-deficient. This creates a strong chemical potential to absorb ions from any material it comes into contact with.
- Aggressiveness: Because it lacks ions, ultrapure water is “hungry” for them. It will readily dissolve and absorb ions from surfaces, such as metals, plastics, and even glass, in an attempt to reach a more stable chemical state.
2. High Resistivity:
- Electrical Properties: Ultrapure water has very high electrical resistivity (around 18.2 megohm-cm at 25°C). This means it does not conduct electricity well due to the absence of free ions. Materials that would normally resist corrosion in regular water can become vulnerable when exposed to ultrapure water because the water can more easily pull ions from the material.
3. Surface Reactions:
- Surface Leaching: When ultrapure water comes into contact with a material, it can leach ions and molecules from the surface, leading to corrosion or degradation. For example, in metals, this can lead to pitting or general corrosion, and in plastics, it can lead to the leaching of additives or plasticizers.
4. Impact on Protective Layers:
- Oxide Layers: Some metals, like stainless steel, rely on a thin oxide layer for corrosion resistance. Ultrapure water can dissolve or disrupt this protective layer, making the underlying metal more susceptible to corrosion.
5. Non-Buffering Nature:
- Lack of Buffering Capacity: Ultrapure water has no buffering capacity, meaning it can easily become acidic or basic if exposed to contaminants or air. This shift in pH can further enhance its corrosive properties.
Conclusion:
Ultrapure water’s corrosive nature is not due to any chemical aggressiveness like that of acids or bases, but rather its extreme purity and strong tendency to equilibrate by absorbing ions and impurities from the materials it contacts. This makes it particularly challenging to handle and store without contamination or material degradation.
Is Ultrapure water corrosive?
Type 1 ultrapure water is so pure that it is actually corrosive to some materials. This is because ultrapure water has an extremely high resistivity (typically 18.2 megohm-cm at 25°C) and lacks any dissolved ions, which means it has a strong tendency to absorb ions and impurities from any material it comes into contact with. This can cause corrosion or degradation in materials that aren’t specifically designed to handle such high-purity water, such as certain metals and even some types of glass or plastics. Because of its aggressive nature, ultrapure water is often used in semiconductor manufacturing, pharmaceuticals, and other applications where even the slightest contamination can have significant consequences.
Some of the recommended materials that can be used for handling and processing ultrapure water include.
1. Polytetrafluoroethylene (PTFE)
- Properties: Excellent chemical resistance, low extractables, high purity, and non-reactive.
- Applications: Tubing, seals, gaskets, and fittings.
2. Perfluoroalkoxy Alkane (PFA)
- Properties: High purity, excellent chemical resistance, and maintains clarity and flexibility.
- Applications: Tubing, fittings, and valves.
3. Polyvinylidene Fluoride (PVDF)
- Properties: Good chemical resistance, high purity, and mechanical strength.
- Applications: Piping, fittings, and valve components.
4. Polypropylene (PP)
- Properties: Good chemical resistance, low cost, and suitable for DI water at lower purity levels.
- Applications: Piping, tanks, and valve bodies.
5. High-Purity Polyethylene (HDPE)
- Properties: Good chemical resistance and high purity.
- Applications: Tubing, containers, and fittings.
6. Polyetheretherketone (PEEK)
- Properties: Excellent chemical resistance, high strength, and low extractables.
- Applications: Tubing, fittings, and pump components.
7. Quartz (Silica)
- Properties: Extremely high purity and inertness.
- Applications: Piping and containers, often in semiconductor processing.
8. Stainless Steel (316)
- Properties: High corrosion resistance, often electropolished for ultra-high purity applications.
- Applications: Piping, valves, and fittings, usually for non-corrosive DI water applications.
- Avoid using 304 grade stainless and ensure all welds have been polished and passivated.
9. Borosilicate Glass
- Properties: High resistance to chemical leaching, but less durable than plastic options.
- Applications: Laboratory containers and some piping systems
Read the next article on ‘Why is ultrapure water corrosive?‘ to find out more.
Is Type 1 or Type 2 water higher quality?
Short answer, type 1 water is purer than type 2, but there is a lot more to take into consideration before specifying one.
As the use of instruments requiring specific qualities of water increases, laboratories are moving away from the traditional Type 1, 2, and 3 specifications and toward a set of guidelines which are laid out in the Clinical and Laboratory Standards Institute (CLSI) G40-A4-AMD guidelines.
These include:
- Clinical Laboratory Reagent Water (CLRW)
- Special Reagent Water (SRW)
There are three main bodies who have had influence in establishing water standards over the years, these are CLSI with the G40-A4-AMD guidelines (mentioned above), ISO with 3696:1987, and ASTM which uses D1193-06.
All of these standards vary in some way and can cause confusion when a grade is specified without directing which organisation’s standard is being referenced. This makes it essential to ensure that your laboratories unique requirements are accounted for when specifying what level of purification you require.
Clinical Laboratory Reagent Water (CLRW)
For reference a standard Purific purification system would fall into the CLRW range with the following properties and is comparable to a traditional Type 2 in water quality. This grade water comes from the regular specifications for blood chemistry analysers requiring this high purity water.
- ≥10 MΩ/cm at 25 °C Resistivity
- <10 CFU/mL
- TOC <500 mg/g (ppb)
- 0.22 µm absolute final filtration near or at the final output stage of the purification system.
Special Reagent Water (SRW)
Special reagent water is used when different quality water to CLRW s required. In essence it is similar to CLRW but may have more or less stringent parameters added to meet the requirements of the laboratories procedures.
Some applications include
- Trace organic analysis.
- DNA and RNA testing.
- Trace metal analysis.
- Cell/tissue/organ culture and florescent antibody detection of microorganisms.
- Low CO2 water.
Feel free to call one of our friendly team to ask further questions should your laboratory require a specific grade water on 1800 573 316 or send an email to service@purific.com
Streamlining Water Purity Analysis with Total Organic Carbon (TOC) Analysis Unit
The purity of water is a crucial factor in many different applications, particularly in healthcare. Medical devices and medicines must be wholly safe and effective to use, which means that keeping water free from impurities is essential. To achieve this essential goal, laboratories must adhere to strict rules set by the TGA and CLSI.
One especially important device for analysing water purity on-site is the Total Organic Carbon (TOC) analysis instrument. With TOC analysis, laboratories can remain compliant with regulatory guidelines while exceeding expectations. If you work in a laboratory setting, you know the importance of maintaining compliance with regulations set forth by governmental and industry organizations. One component of this compliance is ensuring the cleanliness of water used in laboratory processes. This is where a TOC analysis unit comes into play. By analyzing the total organic carbon within water samples, laboratories can guarantee that their water meets CLSI and TGA requirements while also maintaining accuracy in their testing methods.
What is a TOC Analysis Unit?
A TOC analysis unit is a piece of lab apparatus used to calculate the level of organic carbon in a water sample. All biological things and many non-living things, including oil and gas, include organic carbon, which is a group of carbon-containing molecules.
Organic carbon can come from a variety of sources, including naturally occurring organic waste, microbial development, and chemicals employed in the water treatment process. When organic carbon is present in the water, it can impair the purity of the water. As a result, determining the quantity of organic carbon in a water sample is essential for confirming that the water is clean and suitable for use in lab tests.
How Does a Unit of TOC Analysis Operate?
The quantity of organic carbon in a water sample is measured using some techniques using TOC analysis machines. Combustion is a typical technique in which the sample is heated to a high temperature while being exposed to oxygen. The organic carbon in the sample burns to produce carbon dioxide, which is then detected by a detector.
Another popular technique is oxidation, which involves employing a potent oxidising agent like potassium permanganate or sodium persulfate to oxidise the organic carbon in the sample. The amount of oxidising agent used is then used to calculate the amount of organic carbon.
Why is an On-Site TOC Analysis Unit Important for Water Purity Analysis?
In order to comply with CLSI and TGA requirements, laboratories must show that they can generate trustworthy and accurate findings, including for the examination of water purity. Utilising a TOC analysis instrument to monitor the level of organic carbon in water samples is one method laboratories may do this.
Labs can discover possible sources of pollution that may compromise the quality of their water by evaluating the quantity of organic carbon present in a water sample. For instance, if a water sample has significant quantities of organic carbon, the water treatment procedure may not be successful in eliminating toxins from the water.
Additionally, TOC analysis equipment can assist laboratories in proving their adherence to certain TGA and CLSI regulations. For instance, the CLSI advises utilising TOC analysis to keep an eye on the condition of lab water systems, which may be a source of contamination in tests.
In conclusion, Total Organic Carbon (TOC) analysis devices are an essential tool for exceeding compliance requirements with CLSI and TGA standards and providing an in-depth examination of water purity on-site. Laboratories can determine potential sources of contamination and confirm that their water is free of pollutants and suitable for use in laboratory tests by assessing the quantity of organic carbon contained in a water sample.
If you are experiencing problems with your laboratory’s current supply of clean water, get in touch with Purific. With a dependable supply, we would be delighted to help.
Is PP (Polypropylene) or HDPE (High-Density Polyethylene) better for processing DI water?
Both PP (Polypropylene) and HDPE (High-Density Polyethylene) are commonly used for processing DI (Deionized) water, but which one is better depends on the specific application and requirements.
PP is known for its excellent chemical resistance and is often used in applications that require high purity, such as laboratory and medical equipment, as well as in the semiconductor industry. PP is also a good choice for applications that require high-temperature resistance.
HDPE, on the other hand, is known for its toughness and durability. It is commonly used in water treatment applications, including processing DI water, because it is resistant to corrosion and does not react with water or other chemicals.
Overall, both PP and HDPE are good choices for processing DI water. The choice between the two materials will depend on the specific requirements of the application, such as the required level of purity, temperature resistance, and durability.
Reliable Lab Water Supply
A reliable supply of pure water in a lab can be a challenge. You need consistency day in day out, often 24 hours a day.
Here at Purific we get it, and we really do care.
For the last 30 years we have been supporting labs with their pure water needs. So when you ask, who can provide a reliable lab water system? We recommend you reach out to us here at Purific as its what we do and are passionate about. Providing a boutique service to pathology labs we understand the importance of a reliable pure water supply and how every labs needs are different.
If you currently have an unreliable system feel free to reach out, we would love to have a look at how we can support your laboratory.
Talk to one of our legends on 1800 573 316 or email info@purific.com
Purific for life?
Tucked away on the stunning Mornington Peninsular in VIC this old Purific Mini was just replaced …with a new Purific.
The mini was installed back in 2005 and served many years. However with a new Analyser on its way requiring more water, Purific was once again given the opportunity to supply a system that would meet the demands of the new analyser.
Keeping downtime to a minimum was an important part installing the new system, and the lab had to send samples to another location for less than a day.
Purific endeavors to work with our clients to ensure down times are low, reliability is high and the whole process of changing water source is hassle free.
Supporting a laboratory in Kew, VIC.
This Purific system was installed last week and is supplying a Siemens Atellica CM and IM in a growing laboratory in Kew, VIC,
Is reliability important to your laboratory?
Is it crucial that you have a reliable supply of pure or ultra-pure water in your laboratory?
During a recently yearly service of the Purific system pictured below, we found that it had been installed in 1998 and has been in operation ever since. That’s 24 years of service and counting.
We are passionate about what we do, and it is exhilarating when we see a Purific still supporting our customers core laboratory after all these years.
Concerned about service and reliability?…We’d love to talk.
1800 573 316