Combination of Slotted Quartz Tube Flame Atomic Absorption Spectrometry and Dispersive Liquid–Liquid Microextraction for the Trace Determination of Silver in Electroplating Rinse Bath

Abstract

Although flame atomic absorption spectrometry (FAAS) is hindered by its low sensitivity for most elements, it remains a widely used analytical technique in most laboratories. This study was aimed at mitigating the low sensitivity of an FAAS system by using dispersive liquid-liquid microextraction (DLLME) to enrich silver from aqueous solution, and enhance absorbance signals with the help of a slotted quartz tube (SQT). Three major optimization steps were carried for parameters of complexation (silver-dithizone), DLLME method and SQT apparatus. The optimum parameters/variables obtained were applied to aqueous standard solutions, and the developed calibration plots were used to validate the different systems studied. The optimized method (DLLME-SQT-FAAS) recorded an enhancement factor of 98, which correlates to detection and quantification limits of 0.60 µg/L and 2.0 µg/L, respectively. The optimized method was applied to an electroplating rinse solution, and close to 100% recovery results were obtained for different spiked concentrations. These results establish that the developed method can be applied to complex samples for accurate quantification of silver.