Determination of nickel in water and soil samples at trace levels using photochemical vapor generation-batch type ultrasonication assisted gas liquid separator-atomic absorption spectrometry

Abstract

A photochemical vapor generation system with sonication assisted batch type gas-liquid separator was optimized to improve the sensitivity, precision and accuracy of nickel determination by atomic absorbance spectrometry. The inefficient nebulizer sample introduction unit of the flame unit was replaced by a UV assisted vapor generator, and atomization of the generated volatile species was achieved with a quartz tube atomizer. Parameters optimized included organic acid type and concentration, UV irradiation period, sonication period, carrier gas flow rate and atomizer temperature. Recovery studies were performed to determine the method's applicability to real samples, and interference studies were done to ascertain possible effects of the matrix on the analyte. The limits of detection and quantification were found to be 9.5μgL−1 and 31.7μgL−1, respectively. The low relative standard deviation indicated high precision, and experimented results of a certified reference material conformed to the certified value, validating the method's accuracy. Percent recoveries recorded were between 95% and 104% and the interferents tested showed different effects on the absorbance signals of nickel.