Wednesday, May 19, 2010
Lead of a mechanical pencil to measure pollutants in water
An associate professor of Nihon Pharmaceutical University and an analytical equipment manufacturer in Tokyo successfully developed the method to measure the concentration of pollutants like arsenic contained in water and eliminated the necessity to use an expensive platinum electrode. Because the measurement cost is low, this method will be used in developing countries. They plan to put this method into practical use in three years. Because the lead is electricity-conducting and made of carbon with few impurities, the flow of electricity changes depending on the concentration of pollutants if it is put in dirty water. The method enabled them to measure arsenic of 5 micrograms per one liter. This is half the safety standard of arsenic concentration in drinking water specified by WHO. They confirmed that the method provides sufficient degree of precision to confirm the safety of water. An electrode made of metal such as platinum is expensive, and it costs much and requires great care to cleanse it for repeated usage. The lead of a mechanical pencil is inexpensive, and it does not need big equipment for measurement. This method can be used to measure adrenaline in pharmaceuticals and catechin in foods. This method is of great help to developing countries in short of clean water when it is put into practical use.