Determination of platinum in water by ionic liquid-dispersion liquid microextraction combined with graphite furnace atomic absorption spectrometry

[Background] Trace amounts of heavy metal platinum in water can accumulate when ingested by the human body, so it is necessary to accurately determine the trace amount of platinum in water. [Objective] This study aims to develop a new method for the determination of trace platinum in water. [Method] An environmentally friendly reagent ionic liquid was used as the extraction solvent, and the self-made reagent 5- (5-cyano-2-pyridinyl azo) -2, 4-diaminotoluene was used as the chelating agent. The determination was carried out by combining the dispersion microextraction technology with the graphite furnace atomic absorption spectrometer. The factors influencing the microextraction of dispersed fluid were optimized by using single-factor optimization and response surface optimization methods. The optimal experimental conditions were determined and the interactions among various factors were analyzed. [Result] Under optimized conditions, trace platinum in surface water samples from different regions of Shaanxi Province, China was detected, and no platinum metal was found. The standard water sample was determined, and the recovery rate was 103.22%. Surface water samples in Shaanxi Province were determined and spiked recovery experiments were conducted. The result range was 92.79-102.27%. The detection limit of this method is 5.64 ng/mL. [Conclusion] This method is simple to operate, has low cost and short time consumption, and can be applied to the detection of trace platinum in water.