Lab Water Purity- How It Is Assessed and Defined

Water purification system for the laboratory has got its importance, as research scientists are more concerned about the sensitive laboratory applications. Water is used in most laboratory applications as it is used for various purposes. The contaminants present in the water may react chemically with other active materials and produce a negative impact on the results. This manifests the importance of water purity that is used for laboratory applications.

When scientists conduct experiments, it is important to ensure that the liquids used for the experiments are pure. Otherwise, the contaminants present in the liquid might result in risk compromising the integrity of their findings. In case, if any critical research experiments are conducted and water contains contaminants in it then the efforts taken for the experiments can be completely derailed. The measured quality of the water enables scientists to be confident that the pure water used in the analysis does not affect their experiments.

Fortunately, in a modern lab water purification system, You are able to monitor the purity of the water whenever you use it from the water purification system laboratory. This helps scientists to troubleshoot the experimental problem when they are confident that the water that they use is of high quality. 

Who sets laboratory water standards?

There are several organizations that set laboratory water quality standards. These standard specifications ensure the pure water used in the experiments.

  • ASTM (American Society for Testing and Materials)
  • ISO (International Standard Organization)
  • Clinical and Laboratory Standards Institute
  • United States Pharmacopeia and the National Formulary (USP-NF)

These standards enable researchers to gain confidence in the purity of water that they use in laboratory applications. ASTM  has been prevailing for a long time in the Greater Boston laboratory water space. ISO standards are more common in European countries. Here we examine both ASTM  and ISO standard specifications to ensure the quality of the water. 

What factors influence water purity?

There are several factors that influence the purity of laboratory water. The most important factors that are generally measured are discussed here.

  1. pH levels

The pH level plays a crucial role in laboratory analysis. Generally, when the pH value of the solution is 7 it is considered effectively neutral. If the pH level is greater than 7 then the solution is considered as the base solution. If the pH level is lesser than 7 then the solution is considered an acidic solution. If the experiments involve biological processes such as metabolism, circulation, and reproduction it gets affected adversely by the improper pH levels. It is difficult to measure the pH level of the highly purified water as there are no ions present in the water. And hence high-purified water is used to avoid the potential problems that arise from the water impurities.

  1. Temperature

Temperature rise in the water may sometimes increase chemical reactions. Sometimes temperature fluctuations also affect experimental results and so the research scientists maintain the predictable temperature to get accurate results.

  1. Dissolved Oxygen (DO)

Dissolved oxygen is the amount of oxygen found in water and other liquids. Dissolved Oxygen levels of water increase with the aquatic plants and atmospheric oxygen. Dissolved oxygen has been accepted as an important indicator for aquatic life in water bodies. Dissolved Oxygen reduces the odor in the water.

On the other hand, high dissolved oxygen increases the levels of bacteria, algae present in the water. This will affect some of the laboratory applications. It is important to keep the bacterial count to a negligible level. The ultrapure water from the water purification system laboratory keeps the bacterial count to a negligible level.

  1. Turbidity

Turbidity is the measure of the level of transparency caused by suspended or dissolved particles in the water. Purified water is crystal clear with no turbidity. Researchers also ensure pure water with no turbidity for their laboratory analysis.

Contaminants That Affect Lab Experiments

Different contaminants that are present in the water are inorganic ions, organic compounds, particulates, bacteria, and their byproducts, and dissolved gases. Here we discuss how the contaminants affect the lab experiments.

  • Carbon dioxide present in the water can react with water to form carbonic acid and affect the pH level of the water and affect the experimental results.
  • Bacteria and their byproducts present in the water increase their cell growth.
  • Heavy metals present in the water can be toxic and have an adverse effect on laboratory applications.
  • Particulates may damage the experimental instruments.
  • Organic compounds such as fulvic and tannic acids may interfere with experiments and support microbial growth.

Mechanisms Employed to Test Water Purity

Different tests are performed to identify different contaminants. A resistivity meter is used to determine the resistivity of the water. The conductivity of the water is determined by the ionic concentration present in the water. The reciprocal of conductivity is resistivity. In the case of an ultrapure water system for  the laboratory, the ion content is negligible and hence the resistivity is high and the ultrapure water does not conduct electricity.

As research scientists, you are aware that there are many different organic compounds commonly present in the water. Measuring all the organic contaminants independently requires significant effort. Instead the Total Organic Carbon (TOC) content is measured. Performing biochemical reactions by oxidizing organic compounds and the oxidation products are quantified. The chromatography technique is also used to get a better understanding of the organics compounds present in the water.

Bacteria present in the water interfere with laboratory applications and reduce the accuracy of the laboratory analysis. Bacteria present in the water will get multiplied even with the low contraction of nutrition present in the water. It is easy to measure them as they grow faster in the water. Another method is using endotoxins from the cell membranes, generally, Limulus Amebocyte lysate assay (LAL test) is performed to detect the gram-negative bacteria endotoxins.

Colloids and turbidity present in the water block your filters and reduce the efficacy of the reagent. To test, the water is passed through the filter of precision 0.45 µm under constant pressure. The colloidal level is measured by measuring the time taken to damage the filter. This kind of test is usually conducted in the drinking water purification itself. If you detect any colloids in your lab purified water then serious steps to be taken where the water purification system for the laboratory goes wrong and fix it.


The modern water purification system for the laboratory comes with a monitoring system to monitor the water purity with measured values of resistivity at the point of use. Resistivity meter is incorporated with the water purification system laboratory to check the resistivity value of the water at the point of use. 

Lab water purification system provides you with different grades of water, Type1 - ultrapure water, Type 2 - laboratory grade water, Type 3 - primary grade water. Laboratories test the water purity level of the feed water. Depending on the contaminants present in the water the pretreatment is performed. The pretreated water is then passed through the water purification system to produce high purity water for laboratory analysis. This high purified water in the laboratory analysis enhances the accuracy and the performance of the laboratory applications.
Lab Q water products use the latest technologies to get different grades of water. Lab Q ultrapure Type 1 water is the multipurpose laboratory water purifier where you get both Type 1 and Type 2 water in the same lab water purification system. Check Lab Q products to get your best water purification system as per your requirement and enhance the performance of your laboratory application.

More Blogs

Water purification solutions

Water purification solutions

Read More
Two Key Recommendations For Purifying Your Laboratory

Two Key Recommendations For Purifying Your Laboratory

Read More
Foolproof  Lab Water filtration

Foolproof Lab Water filtration

Read More