Double‐LED Source for a Portable Photometer to Determine Iodine and Formaldehyde In Situ

Abstract

An example of using an LED (light emitting diode) as light source to miniaturize the conventional large spectrophotometer is demonstrated by the development of a portable photometer with two LEDs as light source and its application to determination of iodine in edible salt and formaldehyde in the atmosphere, in situ. High speed, good precision, and low cost distinguished the procedure from other methods. The RSD (n ¼ 8) for measurement of iodine in edible salt varied from 0.7% to 1.5%, and the RE (n ¼ 3) for formaldehyde measurement varied from 0.8% to 4.4%. The analytical results obtained were in good agreement with those obtained with a conventional spectrophotometer. The portable instrumentation was demonstrated to be suitable for the quality control of edible salt and ambient air, in-situ.