Sono-Electroanalysis: Application to the Detection of Lead in Petrol

Abstract

The quantitative detection of lead in petrol is shown to be possible by anodic stripping voltammetry in aqueous media under conditions of insonation‐induced emulsification. An immersion horn probe is introduced into a thermostatted conventional three‐electrode cell opposite a mercury plated platinum disk working electrode. Under ultrasonic emulsification of the sample, lead is preconcentrated as an amalgam on the Hg/Pt electrode surface via reduction at –1.0 V (vs. SCE). The large mass transport associated with power ultrasound makes this step highly efficient. Subsequently the lead is quantified by applying an anodic linear sweep of the potential from –1.0 V to –0.15 V (vs. SCE) so as to oxidize the Pb(0) to Pb(II). The area under the stripping peak gives a measure of the lead formed during the initial step. By use of standard microaddition of lead to the solution the system can be calibrated to give the total amount of lead present in the petrol sample. Experiments using samples of 4 star leaded petrol gave a total lead content of 380±40 mgL–1. This value was in quantitative agreement with that obtained by an independent laboratory using atomic absorption spectroscopy (AAS). In addition to the high mass transport and emulsification insonation offers the crucial benefits of first surface activation and cleaning, helping to prevent electrode fouling by the organic components of petrol and second the complete extraction of lead from the water‐insoluble target phase.

Electrochemical Detection of Nitrate at a Copper Modified Electrode Under the Influence of Ultrasound

“…This catalytic layer possesses a number of features that may in certain applications be of more value than the macroporous system. Providing long term stability can achieved, it is conceivable that such a system may be suitable for nitrate analysis in oil based products where the application of ultrasound could be used to both generate the microemulsion [5] needed to release the analyte and provide the enhanced detection.…”

“…The resulting sonovoltammograms bene®t from both the increase in mass transport and continual electrode activation through cavitational cleaning. This direct application of ultrasound has been successfully demonstrated for the determination of ascorbic acid in fruit drinks [4,5] and nitrite in homogenized egg [6].…”

Trace Analysis of Scorodite Mineral for its Osmium and Other Metals Content

“…In this mineral some invaluable metals of platinum group elements (PGE) are present at trace level with other metals.'" 7 " 10 Besides, electroanalytical techniques are being widely used for multielemental analysis in many areas, including geological 11 , biological 12 , industrial 13 , pharmaceutical 14 and environmental 15 studies. With such a large variation in elemental abundances, it is desirable to use a technique that is highly sensitive, especially at minor and trace levels, is specific and precise, and yields a lot of information even in a small sample.…”

Sonoelectrochemical Detection of Copper Within Industrial Effluent: A Critical Assessment

“…Their prevalence however has diminished in recent years as concerns over toxicity and legislative issues relating to the handling and disposal of the waste have begun to mount. As yet, the majority of those applications have utilised mercury film electrodes (4)(5)(6) and thus the efficacy of utilising ultrasound with bare electrodes for the determination of copper required evaluation. Ultrasound has emerged as a particularly powerful weapon in the armoury of the electrochemist (3) and has proven to be extremely beneficial when applied to the analysis of metals within complex media (3)(4)(5)(6).…”