Rapid determination of indium in water samples using a portable solution cathode glow discharge-atomic emission spectrometer

Abstract

A novel method for fast determination of indium in water was established using a homemade solution cathode glow discharger coupled with a portable fiber optical spectrometer. The instrumental parameters and operation conditions which may remarkably influence the analytical performance including the analytical emission line, the solution acidity, etc. were optimized. The resolution of the instrument based on the peak width at half height at 451nm for 2.0mg/L indium solution was about 1.1nm. Under the optimized parameters and conditions, the limit of detection (LOD) was 0.032mg/L calculated by 3SDBLANK/k (n=11). Moreover, the analytical stability was inspected by 7 parallel tests of 0.5mg/L indium standard solution, and the relative standard deviation (RSD) was below 5%. The interferences of potential co-existing metal ions on indium determination were inspected and no significant interferences were observed. This method was applied to the analysis of real water samples available in Beijing and the spiked recoveries were in the range of 94.0%–103.6%, which proved the feasibility of indium determination of real samples. Besides, this method can satisfy the demands of field tests due to the simple and small-sized instrument and less consumption of reagent.