Effects of Water Impurities in Laboratory Use

Water impurities can alter the quality of results in a pharmaceutical setting. These impurities can be introduced from the water supply during the purification process and post-purification, during routine maintenance, or if there are leaks or bursts in the pipes. In this article, we will discuss the effects of water impurities in pharmaceutical uses.

Common Types of Impurities

There are various categories of impurities and contaminants that interfere with pharmaceutical processes. Such impurities can affect the equipment's performance, disrupt lab procedures, and often lead to inaccurate results. These contaminants include:

• Suspended particles This could be sand or silt that is introduced from the water supply. These particles are suspended in water, causing the water to appear turbid.
• Inorganic ions These include cations such as sodium, magnesium, and calcium, as well as anions such as chloride, sulfates, phosphates, and nitrates. 
• Dissolved organic ions These include chloramines, proteins, and remnants of herbicides, pesticides, or detergents. 
• Dissolved gases Gases such as oxygen, nitrogen, and carbon dioxide can be dissolved in water.
• Microorganisms These contaminants include bacteria, viruses, fungi, and algae.
  

How Water Impurities Can Impact Results

Interference with Instruments and Equipment

Impurities in purified water significantly affect the performance and durability of laboratory instruments and pharmaceutical equipment. Some of the adverse effects include:

• Suspended particles, colloids, and other particulate matter may accumulate and clog filters and narrow tubes, thus affecting the equipment's performance. 
• When water with a high concentration of dissolved organic ions is used to prepare liquid chromatography eluents over an extended period, there is a risk of decreased sensitivity and decreased resolution of the apparatus, which reduces the lifetime of the columns used.
• Dissolved ions also decrease the durability of the cartridges used in deionized water systems.

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Inaccurate Results

The presence of impurities in water used for analysis often results in inaccurate results. Erroneous results are highly undesirable in the pharmaceutical industry as they result in misused time and resources. Time is wasted when repeat samples have to be taken for a repeat analysis. Additionally, such errors lead to inefficiency as they delay the release of results.
Here are other ways impurities lead to inaccurate results:

• Significant concentrations of dissolved organic compounds support the growth of microorganisms, interfering with biological experiments.
• Microorganisms such as bacteria and viruses present in purified water contaminate cell and tissue cultures in microbiological tests, affecting results. 
• Inorganic ions distort calibration and give blank signals during ion chromatography, therefore, skewing results.

Procedure Disruption

Impurities present in water can significantly affect laboratory procedures. This can occur in several ways:

• Gram-negative bacteria present in contaminated water release endotoxins and nucleases, which disrupt numerous tests. Nucleases, for instance, disrupt biological experiments involving DNA and RNA. They do this by breaking down the nucleic acids in a sample.
• Dissolved inorganic impurities may cause ionic instability during experiments. This results in disruption of protein-protein interactions and, in turn, affects the rates of the chemical reactions. 
• Dissolved organic impurities decrease the sensitivity of the high-performance liquid chromatography apparatus to the analyte.
• Nitrogen dissolved in water forms bubbles that disrupt spectrophotometric measurements and counting of particulate matter.

These numerous inconveniences can be avoided or minimized by installing a rigorous water purification system. In an ideal situation, water purification systems eliminate all impurities. However, machines are bound to deteriorate or malfunction, leading to a decline in water purity. For this reason, it is critical to regularly monitor the quality of water by performing a series of tests as outlined by the relevant authorities.