Detection of perchlorate in the environment to standards demanded by the US EPA Metrohm and Agilent combine ion chromatography with mass spectrometry
Although manned flight into space has become less frequent since the Columbia accident, rockets still leave the earth almost everyday, for example to bring satellites into orbit or for military purposes.
The driving force used in these rockets is the successor to gunpowder, which was probably first invented by the Chinese about year 1000 and then independently in about 1200 by Berthold Schwarz.
The Chinese and the Franciscan monk used a mixture of potassium nitrate, charcoal and sulphur.
Compared to modern propellants, gunpowder is a weak explosive.
This is why explosives that are used today contain perchlorate.
And this is where the problem starts - many companies that manufacture rockets and rocket propellants are located in the southwestern USA near Las Vegas.
For many years these companies have dumped their perchlorate waste in unchecked land fills or let the waste water run into the rivers, particularly the Colorado.
Today unnaturally high perchlorate concentrations are found in more that 22 states in the USA and more than 15 million inhabitants are exposed to perchlorate in their drinking water.
Perchlorate is a poison that causes serious damage to the thyroid gland even at low concentrations.
This primailry affects newborn infants and babies.
While the US Department of Defense is of the opinion that 200ppb is still acceptable, the EPA (Environmental Protection Agency) finds it necessary to lower the maximum permitted concentration to 1ppb.
Regardless of political opinion, this means that analysts have to detect concentrations of 1ppb or less.
In principle the detection of 1ppb on a Metrohm advanced ion chromatography system is not a problem, but the EPA has decided to make the analysis more realistic, which causes additional difficulties.
In addition to this millionth of a gram of perchlorate, 1kg of sample also contains 3 grams of chloride, nitrate and sulphate.
In principal this is the same as identifying two Swiss inhabitants among the whole of the Swiss population.
So this is where it becomes complicated.
In order to separate the matrix, two systems must be combined with each other: an ion chromatography system with a mass spectrometer.
The ion chromatography separates the sample components and the mass spectrophotometer then evaporates the sample under high vacuum, accelerates the ions, and accurately determines the perchlorate. The Metrohm IC system is thus provided with an additional filter that allows reliable detection of even 0.2 ppb.
Although Metrohm manufacturers extremely efficient IC systems, its product line does not include a mass spectrometer.
In order to still be able to supply systems for the EPA, Metrohm has entered a cooperation with Agilent, the former analytical division of Hewlett Packard (HP), which produces what Metrohm says is the best mass spectrometer available on the market.
