Electromembrane-microextraction of bismuth in pharmaceutical and human plasma samples: optimization using response surface methodology

An electromembrane-microextraction (EME) followed by microcell UV-Vis spectrophotometeric detection was developed for fast and sensitive determination of bismuth in bismuth subcitrate tablets and human plasma samples. To achieve the best extraction conditions, the organic membrane composition and stirring rate were optimized separately by one-variable-at-a-time (OVAT) methodology, and the other effective parameters, including extraction time, applied voltage and composition of acceptor/donor phases, were studied by application of response surface methodology (RSM). The working range was 2.1-800 ng mL(-1), with detection limit of 0.64-1.47 ng mL(-1) of bismuth ions. The enrichment factor was in the range 151-187. Intra- and inter-day relative standard deviations were <6.0%. The developed method was successfully applied for the determination of bismuth in real samples. (C) 2016 Elsevier B.V. All rights reserved.