Mercury determination in petroleum products by electrothermal atomic absorption spectrometry after in situ preconcentration using multiple injections

Abstract

A simple method for mercury determination in petroleum fractions (e.g. naphtha) using electrothermal atomic absorption spectrometry (ETAAS) associated with multiple injection technique for direct preconcentration in the graphite tube has been developed. Oil-in-water microemulsions (three-component solutions) were prepared using a mixture of sample, propan-1-ol and HNO 3. No additional sample pretreatment was required. In the procedure, three successive 30 mL micro-emulsion aliquots are delivered to the graphite tube. The pyrolysis and atomization temperatures were set to 400 1C and 1400 1C, respectively. The calibration curves showed a linear response up to analyte concentrations of 150 mg L À1 with a correlation coefficient of 0.993. The precision calculated from fifteen consecutive measurements and defined as the coefficient of variation of solutions containing 5.0 and 30 mg L À1 of Hg were 6.4% and 4.7%, respectively. The limit of detection (LOD), defined as the Hg concentration that gives a response equivalent to three times the standard deviation (s) of the blank (n = 10), was found to be 0.78 mg L À1. The proposed procedure was used for mercury determination in naphtha feeds processed in Braskem S.A.

Determination of Hg and Pb in Fuels by Inductively Coupled Plasma Mass Spectrometry Using Flow Injection Chemical Vapor Generation

“…The use of more purified reagents should lower the detection limit. As shown in Table 4, the method detection limits obtained by the present procedure are comparable to those for the analysis of petroleum products using contemporary procedures based on direct nebulization after dilution or microwave digestion 11,15,21,35 and vapor generation of the sample after emulsification 35 and/or other detection methods. 9,10,36 …”

“…The combustion of fuel releases toxic elements present in it to the atmosphere and hence it is very important to quantify their concentrations, which would enable us to take preventive measures if necessary. 10 A variety of methods based on AAS, [11][12][13][14][15] ICP-OES [16][17][18][19] and ICP-MS 9,20-25 have been reported for the determination of trace elements in fuels. Most of the techniques require sample pretreatment.…”

The Utilization of Nitrogen Gas as a Carrier Gas in the Determination of Hg Ions Using Cold Vapor-Atomic Absorption Spectrophotometer (CV-AAS)

“…Several methods for the determination of Hg have been reported in the literature, such as potentiometric titration using iodide ion-selective electrodes and anodic stripping voltammetry [5], and some spectrometric techniques, such as cold vapor atomic absorption spectrometry (CV-AAS) [6][7], electrothermal atomic absorption spectrometry (ETAAS) [8], atomic fluorescence spectrometry (AFS) [9], inductively coupled plasma mass spectrometry (ICP-MS) [10] and electrothermal vaporization coupled to ICP-MS (ETV-ICP-MS) [11] were already employed for total Hg determination in the samples.…”

Development of a method for total Hg determination in oil samples by cold vapor atomic absorption spectrometry after its extraction induced by emulsion breaking

“…Undoubtedly, the natural occurrence of Hg in crude oil and its presence in fuels [21,22] contribute significantly to the input of this pollutant to the environment. Some spectrometric techniques, such as cold vapor atomic absorption spectrometry (CV-AAS) [23], electrothermal atomic absorption spectrometry (ETAAS) [24], atomic fluorescence spectrometry (AFS) [25], inductively coupled plasma mass spectrometry (ICP-MS) [26] and electrothermal vaporization coupled to ICP-MS (ETV-ICP-MS) [27] were already employed for total Hg determination in oil samples.…”