Novel extraction induced by microemulsion breaking: a model study for Hg extraction from Brazilian gasoline

Abstract

This paper proposes a novel approach for the extraction of Hg from Brazilian gasoline samples: extraction induced by microemulsion breaking (EIMB). In this approach, a microemulsion is formed by mixing the sample with n-propanol and HCl. Afterwards, the microemulsion is destabilized by the addition of water and the two phases are separated: (i) the top phase, containing the residual gasoline and (ii) the bottom phase, containing the extracted analyte in a medium containing water, n-propanol and the ethanol originally present in the gasoline sample. The bottom phase is then collected and the Hg is measured by cold vapor atomic absorption spectrometry (CV-AAS). This model study used Brazilian gasoline samples spiked with Hg (organometallic compound) to optimize the process. Under the optimum extraction conditions, the microemulsion was prepared by mixing 8.7mL of sample with 1.2mL of n-propanol and 0.1mL of a 10molL HCl solution. Emulsion breaking was induced by adding 300µL of deionized water and the bottom phase was collected for the measurement of Hg. Six samples of Brazilian gasoline were spiked with Hg in the organometallic form and recovery percentages in the range of 88-109% were observed.

Simultaneous Voltammetric Determination of Cd2+ and Pb2+ in Gasoline Samples Employing a Chemically Modified Acrylonitrile‐Butadiene‐Styrene (ABS) Composite Electrode

“…The extraction of Cd 2 + and Pb 2 + from the gasoline samples was performed using the new EIMB strategy proposed in this work for electroanalysis. This methodology was based on previous studies [11][12][13][14], with minor adaptations. First, a microemulsion was formed by mixing 9.2 mL of gasoline with 0.7 mL of n-propanol and 0.1 mL of HNO 3 solution (25 % v/v) in 15 mL falcon tubes made of polyethylene.…”

“…To overcome these problems, Cassella et al . proposed a new method for metal extraction from fuel samples named extraction induced by microemulsion breaking (EIMB) [11–14]. This method is based on the formation and breaking of microemulsions.…”

“…In this process metals are transferred from the sample to the formed extraction phase. Different analytical techniques have been used for metal determination in the EIMB extracts, such as flame atomic absorption spectrometry (FAAS) [11], cold vapor atomic absorption spectrometry (CV ‐ AAS) [12], inductively coupled plasma mass spectrometry (ICP‐MS) [13], and graphite furnace atomic absorption spectrometry (GF‐AAS) [14].…”

“…The determination of trace metals in liquid fuels has drawbacks that may be related to the matrix complexity. To overcome these problems, Cassella et al proposed a new method for metal extraction from fuel samples named extraction induced by microemulsion breaking (EIMB) [11][12][13][14]. This method is based on the formation and breaking of microemulsions.…”

An overview of the Brazilian contributions to Green Analytical Chemistry

“…crude oil and gasoline) as well as biodiesel by emulsion breaking has been widely discussed (Trevelin et al 2016, Pereira et al 2014b, Robaina et al 2016. Recently, Vicentino and Cassella (2017) proposed the hg isolation from gasoline samples by extraction induced by microemulsion breaking. The method required less than 2 ml of solvents, i.e.…”