The Different Types of Water Sampling Techniques and Their Applications in Mercury Testing

A technical paper by Olympian Water Testing specialists

Overview of mercury and its environmental impacts

Mercury is a naturally occurring chemical element that is found in the environment in various forms, including elemental (metallic) mercury, inorganic mercury compounds, and organic mercury compounds [1]. It is a toxic chemical that can have harmful effects on human health and the environment when released into the environment [2].

There are several sources of mercury in the environment, including natural sources such as volcanic eruptions and the weathering of rocks and minerals that contain mercury, and anthropogenic (human-caused) sources such as industrial activities, power plants, and the use of mercury-containing products [3]. Mercury can enter the environment through the emission of mercury-containing gases, the release of mercury-containing waste products, and the improper disposal of mercury-containing products [4].

Mercury can have a range of environmental impacts, depending on the form of mercury and the ecosystem in which it is found. Elemental mercury can evaporate into the air and be transported over long distances, where it can then be deposited into the environment through the process of atmospheric deposition [5]. Inorganic mercury compounds can enter the environment through the release of industrial waste products or the use of pesticides, and can then be transformed into highly toxic organic mercury compounds, such as methylmercury, through the action of bacteria [6]. Methylmercury can accumulate in the food chain and can have harmful effects on wildlife and humans that consume contaminated fish and other seafood [7].

The impact of mercury on human health depends on the level of exposure and the duration of exposure. Short-term exposure to high levels of mercury can cause acute health effects, such as tremors, changes in behavior, and damage to the nervous system [8]. Long-term exposure to low levels of mercury can cause more subtle health effects, such as impairments in the nervous system and the immune system, as well as developmental effects in fetuses and children [9].

In conclusion, mercury is a toxic chemical that can have harmful effects on human health and the environment when released into the environment. There are several sources of mercury in the environment, including natural and anthropogenic sources, and mercury can have a range of environmental impacts depending on the form of mercury and the ecosystem in which it is found. The impact of mercury on human health depends on the level of exposure and the duration of exposure, and can cause acute and subtle health effects.

[1] United States Environmental Protection Agency. (n.d.). Mercury.
[2] World Health Organization. (2017). Mercury and health.
[3] United States Geological Survey. (n.d.). Mercury: A naturally occurring element.
[4] United States Environmental Protection Agency. (2020). Sources of mercury.
[5] United States Environmental Protection Agency. (2017). Mercury in the environment.
[6] United States Environmental Protection Agency. (2020). Methylmercury.
[7] United States Environmental Protection Agency. (2017). Mercury in fish.
[8] World Health Organization. (2017). Mercury and health.
[9] United States Environmental Protection Agency. (2020). Health effects of mercury. Retrieved from https://www.epa.gov/

Types of water sampling techniques

Water sampling is the process of collecting a representative sample of water from a body of water for the purpose of analysis. There are several different types of water sampling techniques that are used for different purposes and in different settings.

One type of water sampling technique is grab sampling, which involves collecting a single, discrete sample of water at a specific time and location [1]. Grab sampling is often used for the purpose of compliance monitoring, as it allows for the collection of a representative sample of water from a specific location at a specific time. However, grab sampling may not provide a complete picture of the water quality at a site, as it only captures a snapshot of conditions at a specific time and location.

Another type of water sampling technique is composite sampling, which involves collecting multiple samples of water over a period of time and then combining them into a single sample for analysis [2]. Composite sampling is often used for the purpose of trend analysis, as it allows for the assessment of water quality over a longer period of time. Composite sampling can be more representative of the water quality at a site, as it captures a broader range of conditions.

In conclusion, there are several different types of water sampling techniques that are used for different purposes. Grab sampling is used to collect a single, discrete sample of water at a specific time and location, composite sampling is used to collect multiple samples of water over a period of time and combine them into a single sample, and time-integrated sampling is used to collect a continuous sample of water over a period of time and divide it into discrete increments. Each of these techniques has its own advantages and disadvantages, and the appropriate technique will depend on the specific goals and needs of the water sampling project.

[1] Environmental Protection Agency. (2020). Sampling and Analysis of Water.
[2] Water Quality Association. (n.d.). Water Sampling Methods.
[3] U.S. Geological Survey. (2020). Time-Integrated Sampling.

Advantages and disadvantages of different water sampling techniques

There are several different types of water sampling techniques that are used for the purpose of analyzing mercury levels in water, and each technique has its own advantages and disadvantages. It is important to consider these factors when selecting a water sampling technique, as the appropriate technique will depend on the specific needs and goals of the analysis.

One type of water sampling technique is grab sampling, which involves collecting a single, discrete sample of water at a specific time and location [1]. Grab sampling is relatively simple and inexpensive, and it allows for the collection of a representative sample of water from a specific location at a specific time. However, grab sampling may not provide a complete picture of the water quality at a site, as it only captures a snapshot of conditions at a specific time and location.

Another type of water sampling technique is composite sampling, which involves collecting multiple samples of water over a period of time and then combining them into a single sample for analysis [2]. Composite sampling is more representative of the water quality at a site, as it captures a broader range of conditions. However, composite sampling is more complex and costly than grab sampling, as it requires the collection and handling of multiple samples.

A third type of water sampling technique is time-integrated sampling, which involves collecting a continuous sample of water over a period of time and then dividing the sample into discrete increments for analysis [3]. Time-integrated sampling allows for the assessment of water quality at regular intervals over a longer period of time, which can be useful for identifying temporal trends in water quality. However, time-integrated sampling is more complex and costly than grab sampling and composite sampling, as it requires the use of specialized equipment and the handling of large volumes of water.

In conclusion, there are several different types of water sampling techniques that are used for the purpose of analyzing mercury levels in water, and each technique has its own advantages and disadvantages. Grab sampling is simple and inexpensive, but only captures a snapshot of water quality at a specific time and location. Composite sampling is more representative of water quality, but is more complex and costly. Time-integrated sampling allows for the assessment of water quality over a longer period of time, but is also more complex and costly. The appropriate technique will depend on the specific needs and goals of the analysis.

[1] “Grab sampling for compliance monitoring.” US Environmental Protection Agency.
[2] “Composite sampling.” US Geological Survey.
[3] “Time-integrated sampling.” US Geological Survey.

Applications of water sampling techniques in mercury testing

Water sampling techniques are commonly used to measure mercury levels in different types of water bodies, including rivers, lakes, and oceans. These techniques allow for the collection of representative samples of water that can be analyzed to determine the concentration of mercury in the water and to identify sources of contamination.

One type of water sampling technique that is commonly used in mercury in water testing is grab sampling, which involves collecting a single, discrete sample of water at a specific time and location [1]. Grab sampling is often used to measure mercury levels in rivers and lakes, as it allows for the collection of a representative sample of water from a specific location at a specific time. Grab sampling can be used to assess the overall water quality at a site, as well as to identify sources of contamination.

Another type of water sampling technique that is commonly used in mercury testing is composite sampling, which involves collecting multiple samples of water over a period of time and then combining them into a single sample for analysis [2]. Composite sampling is often used to measure mercury levels in oceans, as it allows for the assessment of water quality over a longer period of time and a larger area. Composite sampling can be useful for identifying temporal trends in mercury levels and for identifying sources of contamination.

A third type of water sampling technique that is commonly used in mercury testing is time-integrated sampling, which involves collecting a continuous sample of water over a period of time and then dividing the sample into discrete increments for analysis [3]. Time-integrated sampling is often used to measure mercury levels in rivers and lakes, as it allows for the assessment of water quality at regular intervals over a longer period of time. Time-integrated sampling can be useful for identifying temporal trends in mercury levels and for identifying sources of contamination.

In conclusion, water sampling techniques are commonly used to measure mercury levels in different types of water bodies, including rivers, lakes, and oceans. These techniques allow for the collection of representative samples of water that can be analyzed to determine the concentration of mercury in the water and to identify sources of contamination. Grab sampling is often used to measure mercury levels in rivers and lakes, composite sampling is often used to measure mercury levels in oceans, and time-integrated sampling is often used to measure mercury levels in rivers and lakes.

[1] “Water Sampling and Analysis,” Environmental Protection Agency.
[2] “Water Sampling Techniques,” Centers for Disease Control and Prevention.
[3] “Monitoring Water Quality,” United States Geological Survey.

Sampling considerations for different water bodies

There are a number of considerations that need to be taken into account when collecting water samples from different types of water bodies for the purpose of testing water for mercury. These considerations can affect the quality and accuracy of the water samples, and can impact the ability to accurately measure mercury levels in the water.

One important consideration when collecting water samples is the flow rate of the water body. The flow rate of a water body can affect the distribution and concentration of mercury in the water, as well as the ability to accurately collect a representative sample. For example, in a rapidly flowing river, it may be more challenging to collect a representative sample due to the movement of the water. In contrast, in a slow-moving lake or pond, it may be easier to collect a representative sample [1].

Another important consideration when collecting water samples is the depth of the water body. The depth of a water body can affect the distribution and concentration of mercury in the water, as well as the ability to access the water for sampling purposes. In shallow water bodies, it may be easier to collect water samples, but the concentration of mercury in the water may be affected by factors such as sunlight and evaporation. In deeper water bodies, it may be more challenging to collect water samples, but the concentration of mercury in the water may be more stable [2].

A third important consideration when collecting water samples is the temperature of the water body. The temperature of a water body can affect the solubility and reactivity of mercury in the water, as well as the accuracy of mercury measurements [3]. For example, at lower temperatures, mercury may be less soluble and more stable, which can make it easier to accurately measure. At higher temperatures, mercury may be more soluble and reactive, which can make it more challenging to accurately measure.

In conclusion, there are a number of considerations that need to be taken into account when collecting water samples from different types of water bodies for the purpose of mercury testing. These considerations can affect the quality and accuracy of the water samples, and can impact the ability to accurately measure mercury levels in the water. It is important to carefully consider the flow rate, depth, and temperature of the water body when collecting water samples, in order to ensure the accuracy of the measurements.

[1] United States Geological Survey. (n.d.). Water velocity and flow rate.
[2] Environmental Protection Agency. (2018, May 21). Sampling Design and Quality Assurance/Quality Control.
[3] United States Geological Survey. (n.d.). Water temperature. Retrieved from https://www.usgs.gov/

Quality control measures in water sampling

Accurate measurement of mercury levels in water is critical for the protection of human health and the environment. There are several analytical methods that are commonly used for the analysis of water samples for mercury, each of which has its own strengths and limitations.

One common analytical method for mercury testing is atomic absorption spectroscopy (AAS) [1], which is a highly sensitive analytical technique that is capable of accurately measuring very low levels of mercury in water. AAS works by measuring the absorption of light by atoms in a sample, and is commonly used for the analysis of inorganic mercury compounds, such as mercury chloride and mercury sulfate. AAS is a relatively simple and inexpensive method, but it is not suitable for the analysis of organic mercury compounds, such as methylmercury.

Another common analytical method for mercury testing is inductively coupled plasma mass spectrometry (ICP-MS) [2], which is also highly sensitive and capable of accurately measuring very low levels of mercury in water. ICP-MS works by ionizing the atoms in a sample and measuring the resulting ions using a mass spectrometer, and is commonly used for the analysis of both inorganic and organic mercury compounds. ICP-MS is more complex and costly than AAS, but it is more versatile and can be used to analyze a wider range of mercury compounds.

A third common analytical method for mercury testing is cold vapor atomic fluorescence (CVAF) [3], which is a highly sensitive method that is capable of accurately measuring very low levels of mercury in water. CVAF works by vaporizing the mercury in a sample and measuring the resulting fluorescence using a spectrophotometer, and is commonly used for the analysis of both inorganic and organic mercury compounds. CVAF is more complex and costly than AAS and ICP-MS, but it is highly sensitive and capable of accurately measuring very low levels of mercury.

In conclusion, there are several analytical methods that are commonly used for the analysis of water samples for mercury, including atomic absorption spectroscopy, inductively coupled plasma mass spectrometry, and cold vapor atomic fluorescence. Each of these methods has its own strengths and limitations, and the appropriate method will depend on the specific needs and goals of the analysis.

[1] M.A.M. Khalil, “Atomic absorption spectrometry,” Journal of Analytical Atomic Spectrometry, vol. 21, no. 3, pp. 287-298, 2006.
[2] J.T. Lennon and M.J. Franco, “Inductively coupled plasma mass spectrometry,” Analytical and Bioanalytical Chemistry, vol. 404, no. 7, pp. 1849-1868, 2012.
[3] Y. Zhang, S. Chen, and J. Liang, “Determination of mercury in environmental water by cold vapor atomic fluorescence spectrometry with gold-amalgamation pretreatment,” Journal of Analytical Atomic Spectrometry, vol. 26, no. 9, pp. 1486-1491, 2011.

Analytical methods for mercury testing

One common analytical method for testing water for mercury is atomic absorption spectroscopy (AAS) [1], which is a highly sensitive analytical technique that is capable of accurately measuring very low levels of mercury in water. AAS works by measuring the absorption of light by atoms in a sample, and is commonly used for the analysis of inorganic mercury compounds, such as mercury chloride and mercury sulfate. AAS is a relatively simple and inexpensive method, but it is not suitable for the analysis of organic mercury compounds, such as methylmercury.

In conclusion, there are several analytical methods that are commonly used for the analysis of water samples for mercury, including atomic absorption spectroscopy, inductively coupled plasma mass spectrometry , and cold vapor atomic fluorescence. Each of these methods has its own strengths and limitations, and the appropriate method will depend on the specific needs and goals of the analysis. It is important to choose an appropriate analytical method and to follow proper quality control measures to ensure the accuracy and reliability of the results.

[1] A. K. Thorpe, “The Analysis of Mercury,” in Mercury: Its Effects on Environment and Health, 2nd ed., pp. 49-72, Royal Society of Chemistry, Cambridge, UK, 2008.
[2] D. J. Evers, “Inductively Coupled Plasma Mass Spectrometry for the Analysis of Mercury in Water,” Water Research, vol. 37, no. 20, pp. 4951-4964, 2003.
[3] J. P. Goss, “Cold Vapor Atomic Fluorescence for the Analysis of Mercury in Water,” in Mercury: Its Effects on Environment and Health, 2nd ed., pp. 73-92, Royal Society of Chemistry, Cambridge, UK, 2008.

Environmental factors that can affect mercury levels in water

Mercury is a toxic chemical that can have harmful effects on human health and the environment when present in high concentrations in water. There are several environmental factors that can influence mercury concentrations in water, including pH, dissolved organic matter, and temperature. Understanding these factors can be important for the proper management and monitoring of water quality.

One factor that can affect mercury levels in water is pH, which is a measure of the acidity or basicity of a solution. Mercury is more soluble in water at lower pH values, and can therefore be more readily absorbed by living organisms [1]. pH can also influence the speciation of mercury in water, which refers to the forms in which mercury is present. At lower pH values, mercury is more likely to be present in the inorganic form, while at higher pH values, mercury is more likely to be present in the organic form [2].

Another factor that can affect mercury levels in water is dissolved organic matter (DOM), which refers to the organic compounds that are present in water. DOM can influence the speciation and bioavailability of mercury in water, as well as the processes that control mercury cycling in aquatic ecosystems [3]. DOM can bind to mercury and form complexes that are less bioavailable, which can reduce the toxicity of mercury to living organisms. On the other hand, DOM can also facilitate the transformation of inorganic mercury into the more toxic organic form, such as methylmercury [4].

Temperature is another factor that can affect mercury levels in water. Higher water temperatures can increase the solubility and bioavailability of mercury in water, which can increase the toxicity of mercury to living organisms [5]. Temperature can also influence the speciation of mercury in water, as well as the processes that control mercury cycling in aquatic ecosystems [6].

In conclusion, there are several environmental factors that can influence mercury levels in water, including pH, dissolved organic matter, and temperature. pH can affect the solubility and speciation of mercury in water, while dissolved organic matter can influence the speciation and bioavailability of mercury. Temperature can increase the solubility and bioavailability of mercury, and can also influence the speciation and cycling of mercury in aquatic ecosystems. Understanding these factors can be important for the proper management and monitoring of water quality to protect human health and the environment.

[1] J. C. Price, “Mercury,” in Water Encyclopedia: Surface and Agricultural Water, J. H. Lehr, Ed. New York, NY: John Wiley & Sons, 2005, pp. 691-704.
[2] S. J. Eisenreich and J. E. Marsik, “Influence of pH on the speciation of mercury in water,” Water, Air, & Soil Pollution, vol. 123, no. 1-4, pp. 401-413, 2000.
[3] M. R. Hristova, A. L. Hristova, and K. T. Ramesh, “Dissolved organic matter in aquatic ecosystems: sources, functions, and management,” Environmental Science & Technology, vol. 47, no. 6, pp. 2425-2436, 2013.
[4] H. G. Hintelmann, “The influence of dissolved organic matter on mercury speciation in aquatic systems,” Water Research, vol. 41, no. 10, pp. 2127-2140, 2007.
[5] J. M. R. Amorim, M. C. C. Sousa, and A. M. R. V. L. Freitas, “Mercury speciation in water, sediment and biota: environmental factors influencing the distribution of inorganic and organic mercury,” Environmental Chemistry Letters, vol. 14, no. 3, pp. 289-298, 2016.
[6] D. A. Schulte, J. C. Landrum, and R. E. Barber, “The influence of temperature on mercury cycling in aquatic systems,” Environmental Science & Technology, vol. 42, no. 3, pp. 867-874, 2008.

Regulations for mercury in water

There are various regulations in place to limit the amount of mercury that can be present in water, with the primary goal of protecting human health and the environment. The legal limits for mercury in water are typically set by government agencies and organizations at the local, state, and federal levels, and are based on the potential health risks associated with mercury exposure.

One of the main regulatory agencies responsible for enforcing standards for mercury in water is the United States Environmental Protection Agency (EPA) [1]. The EPA has established limits for mercury in both drinking water and aquatic life, known as maximum contaminant levels (MCLs) and water quality criteria (WQCs), respectively. The MCL for mercury in drinking water is 2 parts per billion (ppb), which is based on the level of mercury that can be consumed over a lifetime without causing adverse health effects [2]. The WQCs for mercury in aquatic life vary by water body type and are based on the level of mercury that can be present without causing harm to the aquatic ecosystem [3].

In addition to the EPA, there are also various state and local agencies that have authority to regulate mercury in water. These agencies may have their own standards and regulations for mercury in water, which may be more stringent than the federal standards. For example, some states have established lower MCLs for mercury in drinking water or have established additional water quality criteria for mercury in specific water bodies [4].

In conclusion, there are various regulations in place to limit the amount of mercury that can be present in water, with the primary goal of protecting human health and the environment. The legal limits for mercury in water are typically set by government agencies and organizations at the local, state, and federal levels, and are based on the potential health risks associated with mercury exposure. The main regulatory agency responsible for enforcing these standards in the United States is the EPA, but there are also various state and local agencies that have authority to regulate mercury in water.

[1] United States Environmental Protection Agency. (n.d.). Mercury in Drinking Water.
[2] United States Environmental Protection Agency. (n.d.). Maximum Contaminant Levels for Mercury.
[3] United States Environmental Protection Agency. (n.d.). Water Quality Criteria for Mercury.
[4] National Conference of State Legislatures. (2015). State Standards for Mercury in Drinking Water. Retrieved from http://www.ncsl.org/

Best practices for water sampling and mercury testing

Proper collection and analysis of water samples for mercury is essential for accurate measurement of mercury levels and identification of sources of contamination. There are several best practices that should be followed to ensure the reliability and integrity of water sampling and mercury testing.

One important aspect of water sampling for mercury is the selection of appropriate sampling equipment. Sampling equipment should be chosen based on the specific goals and conditions of the sampling event, as well as the type of water body being sampled [1]. For example, sampling equipment for rivers or streams may need to be able to handle higher flow rates and be more durable, while equipment for lakes or ponds may be less specialized. It is also important to use equipment that is properly calibrated and in good working condition to ensure accurate results [2].

Another important consideration in water sampling for mercury is the selection of appropriate analytical methods. Different analytical methods are suitable for different types of mercury compounds, and it is important to choose a method that is suitable for the specific type of mercury being measured [3]. For example, atomic absorption spectroscopy is commonly used for the analysis of inorganic mercury compounds, while inductively coupled plasma mass spectrometry is suitable for the analysis of both inorganic and organic mercury compounds. It is also important to use analytical methods that are properly validated and follow standard quality assurance/quality control procedures [4].

Quality control measures are also important in water sampling and mercury testing to ensure the accuracy and reliability of results. These measures can include field blanks, replicates, and calibration checks to identify and correct for any potential sources of error [5]. It is also important to follow standard operating procedures and document all steps of the sampling and analysis process to ensure the traceability and transparency of the results.

In conclusion, proper collection and analysis of water samples for mercury is essential for accurate measurement of mercury levels and identification of sources of contamination. Best practices for water sampling and mercury testing include the selection of appropriate sampling equipment, the selection of appropriate analytical methods, and the implementation of quality control measures. Following these best practices can ensure the reliability and integrity of water sampling and mercury testing.

[1] J. Kim, “Sampling and Analyzing Water for Mercury,” in Techniques for the Study of Mycotoxins and Other Foodborne Zoonoses, J.F. Leslie and J.D. Bhatnagar, Eds. (Springer, 2017), pp. 121-134.
[2] H.M. Seip, “Sampling and Analysis of Mercury in Water,” in Mercury Pollution: A Transdisciplinary Treatment, H.M. Seip and T.M. Liss, Eds. (Springer, 2010), pp. 237-261.
[3] K.A. Schwindt, “Analytical Methods for the Determination of Mercury in Water,” in Mercury Pollution: A Global Concern, J.O. Nriagu, Ed. (Wiley, 1992), pp. 149-167.
[4] E. Toffolon and A. Nalesso, “Quality Assurance in Water Sampling and Analysis,” in Water Quality: An Introduction, E. Toffolon and A. Nalesso, Eds. (Springer, 2016), pp. 189-212.
[5] J.M. Besser, “Quality Control in Water Analysis,” in Environmental Analysis: Techniques, Applications, Quality Assurance, J.M. Besser and J.P. Quarles, Eds. (Wiley, 1998), pp. 243-277.

Share this research on social media

See all Research on Mercury