Detection of heavy metal ions in aqueous solution using fiber optic sensor

Heavy metal is one of the common pollutants which have dangerous potential for bioaccumulation that causing heavier exposure and serious disease for some organisms. In this paper, aluminium nitrate (Al(NO₃)₃), calcium nitrate (Ca(NO₃)₂) and magnesium nitrate (Mg(NO₃)₂) will be used as the source to prepare standard sample solution with concentration from 50 μM to 500 μM. An etched fiber optic was used as the sensor probe for the detection of heavy metal ions in the sample solution. Part of the fiber optic was etched with acetone so that its cladding is completely removed and then dip into the sample solution for detection. The sample solution will have direct contact with the fiber optic core and act as a new “cladding” for the fiber optic core. The halogen lamp light source (ProLamp) and ASD FieldSpec 3 Hi-Res Spectroradiometer which cover a wide spectrum range from 350 nm to 2500 nm were used for the detection of heavy metal. By observing and comparing the output spectrum, detection for the concentration of the sample heavy metal ions in aqueous solution can be done.