The detection of lead ion level in distilled water using 405 nm laser light and optical probe based on the directional coupler

The development of lead ion detection systems is expected to have an advantage in terms of simplicity of the device and easy to trace the of level lead ion in the water. The level of lead ion in water that is allowed into the human body is 0.01 ppm. In this work, an alternative methode to detect the concentration of lead ion in water using 405 nm laser light and optical probe based on the directional coupler is proposed. The proposed methode to detect the concentration of lead ion is using directional coupler and flat mirror as a reflecting component. The performance of this new detection system that was developed will be shows: (i) sensitivity; (ii) linearity; (iii) operation range; and (iv) the limit of detection (LOD). To shows this performance, the system was tried to detect the concentration of lead ion in distilled water from 0.01 ppm to 0.07 ppm with four replication for each concentration. The performance of this alternative methode to detect lead ion has a 26.78 mV/ppm of sensitivity of with a linearity more than 99%, operation range operation range start from 0.01 ppm to 0.07 ppm, and LOD reaches 0.01 ppm.