Continuous ultrasound-assisted extraction coupled to flow injection-pervaporation, derivatization, and spectrophotometric detection for the determination of ammonia in cigarettes.
A dynamic system for the continuous removal of ammonia from cigarettes with ultrasound assistance and iterative change of the flow direction of the extractant through the sample cell has been developed. A 0.1-g sample of cigarette was subjected to 7 min of ultrasound-assisted extraction (application and duration of pulse 0.7 s, output amplitude 85% of the converter nominal amplitude), and 1 M NaOH solution was used both as extractant and as carrier in the dynamic system. The ultrasound-assisted extractor was coupled to a pervaporation unit through a flow injection interface in order to develop a fully automated method. In arriving at the pervaporator, the ammonia is transferred from the donor-carrier stream to an acceptor stream, where the classical Berthelot reaction takes place--thus favoring pervaporation. The blue complex formed is spectrophotometrically monitored at 655 nm. The method was applied to the determination of ammonia in a selection of 10 European cigarette brands and Kentucky Reference 2R4F cigarettes.
Caballo-López
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A
Department of Analytical Chemistry, Annex C-3, Campus of Rabanales, University of Córdoba, E-14071, Córdoba, Spain.
Luque de Castro
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MD
D000641:Ammonia / Q000032:analysis* / Q000737:chemistry; D017022:Flow Injection Analysis / Q000295:instrumentation / Q000379:methods; D007629:Kentucky; D012680:Sensitivity and Specificity; D013053:Spectrophotometry / Q000379:methods; D014026:Nicotiana / Q000737:chemistry*; D014465:Ultrasonics
D000641:Ammonia