Development of a Methodology Based on Extraction Induced by Emulsion Breaking for Copper Determination in Gasohol by Graphite Furnace Atomic Absorption Spectrometry

The development of a method based on extraction induced by emulsion breaking (EIEB) aiming copper determination in gasohol using graphite furnace atomic absorption spectrometry (GF AAS) is reported. Emulsification the samples was carried out nitric acid solution, (1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol surfactant (Triton X-114), and ultrasound energy. variables related to efficiency were optimized multivariate approaches (two-level factorial fractional design Doehlert design). best results obtained when formed with 5.0 mL sample, 0.200 2.4 mol L-1 HNO3, 0.100 10% Triton X-114 10 min sonication. A fast efficient performed at 90 oC. volume 6.65 copper-rich hydroalcoholic phase extracted, separated from organic analyzed. Under these conditions, following analytical characteristics obtained: 0.61 2.0 µg for limits detection quantification, respectively; precision (percentage relative standard deviation, L-1) 2.8%; sensitivity 0.011 L -1. Accuracy assessed spike tests, values range 95-110% achieved. applied Brazilian gasoline (gasohol 27% ethanol).