Development of a New and Highly Sensitive Method for Arsenic Determination in Drinking Water Samples Using Au‐Coated W‐Coil Atom Trap Hydride Generation Atomic Absorption Spectrometry

Abstract

A novel ultra‐sensitive gold‐coated tungsten‐coil atom trap coupled with HGAAS was developed for the first time for the determination of arsenic. The analytical methodology was based on transporting and in‐situ trapping of arsine produced by the hydride generation system onto a gold‐coated W‐coil trap for preconcentration via Ar and H2 gases. The trap surface was examined using scanning electron microscopy and energy‐dispersive X‐ray spectroscopy. SEM images revealed that the surface is covered with hexagonal and pentagonal structures on a micro scale with gold. The experimental parameters were optimized for both trap and non‐trap method. The enhancement factor for the characteristic concentration (C0) was determined to be 15.3 when compared with the non‐trap methods. For the trapping time of 120 s using the developed method, the limit of detection (LOD) and the precision were determined as 4.8 ng L−1 and 3.6 %, respectively. The interference effects of various hydride‐forming ions were examined in detail. The accuracy of this ultrasensitive methodology was successfully verified by analysis of certified reference materials and some drinking water samples.. t‐test was implemented to the water samples, the added and measured concentrations exhibited no statistically meaningful distinction at the 95 % confidence level.