When someone says “clean water,” what image comes to mind? For consumers, it could be a glass of clear, sparkling water but for many environmental agencies, this can range from a clear liquid to a muddy-looking substance that is not usually safe for drinking. Monitoring by these agencies analyzes drinking water, surface water, ground water, and wastewater for compliance with regulations to protect the environment and ensure a sustainable future.
The International Standards Organization (ISO), a worldwide federation of national standards bodies with 163 member countries, has issued 19,500 standards regulating industries from technology to healthcare. In December 2013, they issued the ISO 15923-1 which specifies methods for the automatic performance of spectrophotometric and turbidimetric analyses with a discrete analysis system for determining ammonium, nitrate, nitrite, chloride, orthophosphate, sulfate, and silicate levels. The focus of this standard is ground, potable, surface, waste, eluates, and boiler water. According to the requirements of the standard, a large number of different parameters needed to be determined using a single instrument where desired tests could be specified for each sample type.
With the use of a discrete photometric analyzer (Thermo Scientific Gallery, Gallery Plus, or Aquakem instruments), samples that fall outside of the normal measuring range can be diluted automatically and measured again in a different range. In addition, these analyzers can also perform tests for alkalinity, calcium, chromium VI, fluoride, ferrous iron, magnesium, nitrate (with enzymatic or vanadium chloride reduction), total hardness, and urea. A separate electrochemical unit can measure pH and conductivity.
Starcross National Laboratory Service, Environmental Agency (NLS EA) located in Exeter, United Kingdom, is one of three government facilities in the UK charged with examining environmental samples. The facility in Exeter evaluates clean water samples receiving between 400 and 1000 samples per day, or an average of 600 samples per day. When samples arrive at the facility they are bar-coded, organized and divided by type. Although classified as clean water their appearance can range from somewhat clear to muddy brown. Each sample could be analyzed in 5 to 30 tests including low or high level phosphate (PO4), nitrite, nitrate, silica, ammonia, chloride, and alkalinity. Samples may be filtered or digested prior to specific analysis to ensure valid results.
The NLS EA is well respected for its capability in detecting very low levels of ammonia at one part per billion. They currently have five discrete analyzers in use with one dedicated solely to tests for post digestion total phosphorus (P) and PO4. Results from completed tests often need to be rigorously precise and accurate in order to withstand legal scrutiny. Using a discrete analysis system offers the added benefit of independent completion of test runs within hours compared to former techniques that required a full day.
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Isthe volume of samples challenging your water analysis techniques and is automated photometric determination of interest to your laboratory? If so, we would like to hear about your experience.