The miniaturised solid phase extraction of some trace metals using graphene nanoplatelets by GFAAS

In order to separate and enrich of cadmium, copper, lead and nickel before its determination with graphene nanoplatelets by atomic absorption spectrometry was described. For this aim, analyte elements were collected on sorbent in mini filter. The influences of experimental conditions (pH of sample, amount of sorbent, concentration of eluent, foreign ions), retention and elution parameters on the recovery of the analyte elements were examined. After the optimisation of experimental parameters, a successful separation and enrichment were obtained at pH = 7 and eluted with 0.1 M of HNO₃ applying a 20 mL/min of drawing and discharging rates for sorption and elution steps with high (>95%) quantitative recovery and high precision (<10% relative standard deviation). Using the proposed technique, the cadmium, copper, lead and nickel in various water samples (tap water and river water) could be practically and easily removed and enriched with 95% confidence level. The limit of detection for cadmium, copper, lead and nickel was 0.78, 0.41, 5.40 and 0.44 μg/L (3σ, N = 10), respectively. The proposed technique was fast, simple, environmental friendly and economic.