Analysis of Mercury in Water - Research Paper Example

Most of the analysis methods used today were developed in the late 1960’s and early 1970’s and are immensely dependent on laboratory equipment. However, in the wake of the technological evolution, several other high-tech methods have been developed as we will see with the Anthony’s Mercury Analyzer. Most of these advanced methods not only provide for the basic laboratory setting but also for field purposes. Purge and Trap - since the discovery of elemental Mercury in water, there is no doubt that this method is one of the best for analyzing Mercury in the field.

Basically, this method entails purging water samples with nitrogen and consequently extracting Mercury from the samples prior to analyzing the levels using Mercury analyzers. This method was widely used in the early 1990’s to screen water samples from wells and construction sites across the United States (U.S. Environmental Protection Agency p. 2). However, due to its lack of sensitivity and prone to environmental factors, this method is limited especially when trying to retrieve precise measurements from the samples owing to the contamination of reagents in the field (Murphy & Dooley p.2) Cold Vapour Atomic Absorption Spectrometry- in an attempt to refine the purge and trap method, cold vapour atomic absorption spectrometry method, has become synonymous with various chemists around the world due to its precision.

In this technique, Mercury is reduced to a free atomic state by chemically reacting to the sample with a strong reduction agent like sodium borohydride in a sealed reaction system. The free Mercury, which is now volatile, is then forced from the reaction container by effervescing gases in the solution. Mercury atoms are then transmitted in the stream of gas to a connected absorption cell, which is positioned on the path of light from the atomic absorption spectrometer and the readings relayed to the analyzers.

The sample is then digested in potassium permanganate-potassium persulfate and oxidized for two hours at 95 degrees. The resultant Mercury levels are then measured using automated Mercury analyzers (Hirata p. 4). Oxidation- this is rather a more advanced method of analyzing methyl Mercury and involves extraction of methyl Mercury by pre-treatment in dithizone-toulene solution. The resultant solution is injected into a Gas-liquid Chromatograph with electron capture detector (GLC-ECD) with chlorine gas.

The results from the reaction are then used to determine the level of Mercury in the test sample since Mercury is sparingly soluble in water. Owing to its high precision this is one of the best methods used in the test of methyl Mercury and moreover inorganic Mercury. This method is generally applied when analyzing Mercury in food samples such as fish and also Mercury analysis in human blood (Suzuki p. 97). However, due to the high costs associated with this method, chemists and environmental analysts rarely use it as sometimes there might be a need to conduct multiple analyses on the same sample or repeating the procedure more than twice to refine the final results.

Most of the above methods require specialized equipment and the analysis is usually conducted in laboratories hence making the above methods inflexible. With the advancement in technology however, more reliable and advanced techniques are continually being developed. Anthony’s Mercury Analyzer is a unique technique that builds