Avoiding Health Risks by Understanding Water Contaminants

Ensuring the quality of drinking water is crucial for maintaining public health and safety. Contaminants in drinking water can not only affect its taste and appearance but also pose significant health risks. This article dives into the importance of monitoring water quality, focusing on the detection and analysis of chlorine and iron content using a specific method of analysis.

Water Standards

Drinking water can contain various contaminants, ranging from inorganic materials like lead and iron to organic compounds such as carbon tetrachloride and glyphosate. The presence of these impurities can lead to health issues, prompting governing agencies to set standards for safe levels of these substances in drinking water. The US Environmental Protection Agency (EPA) has established protective drinking water standards for more than 90 contaminants, including drinking water regulations issued since the 1996 amendments to the Safe Drinking Water Act that strengthen public health protection.

The presence of iron in drinking water can lead to a change in flavor as well as discoloration of water. While the presence of iron does not lead to a significant health concern, it can be helpful to test for both aesthetic purposes (i.e., taste and smell) and to check for corrosion in facility machinery. As such, the US EPA has outlined secondary drinking water standards for materials like iron which do not pose significant health concerns, but which can still be useful to monitor for aesthetic purposes.

While iron content is related more to the appearance and taste of drinking water, there are other contaminants which can pose a risk to public health. For example, the growth of bacteria can be a concern for drinking water. To avoid this, disinfectants are often used to prevent the growth of bacteria or remove the colonies already grown. These disinfectants often include chlorine and/or chloramine. While this removes the risk of bacterial growth, too much of these disinfectants can also be harmful. Consequently, it is important that the amount of chlorine present is known to ensure it does not exceed safe levels.

The Role of UV-Visible Absorption Spectroscopy

One effective method for analyzing water quality is UV-Visible absorption spectroscopy. Ultraviolet-visible spectroscopy, or UV-Vis, is an analytical technique used to measure the absorbance of a sample in the ultraviolet and visible regions of the electromagnetic spectrum, typically from about 200 nm to 800 nm. This technique is based on the interaction of UV-Visible light with a sample, initiating transitions between the electronic ground state and excited states within the compound. These transitions are specific to each compound, allowing for qualitative and quantitative analysis. This method is advantageous because it is fast, non-destructive, and provides valuable information unique to the measured substance.

Testing for Iron and Chlorine Using UV-Vis

A UV-Vis spectrophotometer was utilized In a study involving chlorine and iron analysis for drinking water quality. Two colorimetric analyses were used to analyze the total chlorine and iron content in tap water samples. The pre-built methods included in a particular water analysis software were employed for these analyses. Additionally, standard solutions were used to test the accuracy of these methods.

For iron analysis, the 1,10-phenanthroline method was used, which involves converting free iron ions to a detectable form. The UV-Visible absorption spectra for the water analysis reagents with and without iron were measured to determine the iron content. Similarly, for chlorine analysis, the interaction between the analyte and the colorimetric reagent produced a color change, which was observed through UV-Visible absorption spectroscopy.

Results

The study demonstrated the reliability and accuracy of the pre-built water analysis methods for detecting chlorine and iron in drinking water. The analysis of two tap water samples showed that the water was below the designated levels for chlorine and iron, as expected. This confirmed the effectiveness of this fast and non-destructive technique for water quality analysis.

For iron analysis, the samples were measured at 510 nm. The absorbance for both samples was below the noise level, indicating that if iron was present, it was in such low quantities that it could not be detected using the UV-Visible techniques employed. This result aligns with the guidelines set by the Environmental Protection Agency (EPA), which outlines acceptable iron levels in drinking water.

For chlorine analysis, the samples were analyzed using a specific reagent kit. The absorbance measurements indicated that the chlorine content in the samples was below the acceptable limit, demonstrating the efficacy of the UV-Visible absorption technique in detecting chlorine levels.

You can read additional details about the study, including methodology, instruments used, table of standards, sample preparation, and absorption spectra in the application note: UV-Vis spectroscopy for drinking water quality

Summary

The study highlights the importance of monitoring drinking water quality to ensure it is free from harmful contaminants. The use of UV-Visible absorption spectroscopy provides a reliable, fast, and non-destructive method for analyzing common substances like chlorine and iron in water. The results from the study confirm that the pre-built water analysis methods are accurate and effective for ensuring drinking water meets safety standards.

As we noted, maintaining the quality of drinking water is vital for public health. Advanced analytical techniques like UV-Visible absorption spectroscopy help play a crucial role in monitoring and ensuring the safety of our water supply. By using these methods, we can detect and quantify contaminants accurately, helping to ensure that the water we consume is clean and safe.