Stripping potentiometry for organolead compounds: application to the determination of total lead in gasoline

✍ Scribed by Daniel Jagner; Lars Renman; Yudong Wang

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 443 KB
• Volume: 267
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(92)85019-3

✦ Synopsis

A lo-p1 gasohne sample IS added to 590 ~1 of a modlfymg matnx composed of 15 g I-' mercury(H), 0 50 M nitric acid and 1% (v/v) Trlton X-100 m 90% ethanol Tetraethyl-and/or tetramethyllead (TEL and TML, respectively) are reduced and simultaneously amalgamated on a glassy carbon electrode employmg a pulsed electrolysis sequence, and the amalgamated lead IS re-oxldlzed by means of a constant current One analysis, which IS performed automatically under computer control with a commercial potentlometrlc stnppmg analyser, takes approximately 5 nun including the time for sample preparation and result evaluation The system IS calibrated by means of a single-point cahbratlon usmg a standard prepared m lsooctane and containing 15 mg I-' of lead, half from TEL and half from TML The relative difference m sensitivity between TEL and TML IS 8%, m accordance unth theory The method IS best suited for unleaded gasoline wth total lead concentrations m the range 0 l-30 mg 1-l of total lead The results obtained agree well with those obtained by atomic absorption spectrometry The estimated preclslon IS 4-8% (R S D ) and the detection hmlt 0 07 mg 1-l of total lead