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

• Electromembrane extraction (EME) was coupled with a microcell UV–Vis spectrophotometric method.
• This is the first report on EME technique for determination of Bi(III).
• The proposed method was applied for fast and selective determination of Bi(III) in the different real samples.
• The effective parameters on EME were optimized using face-centered central composite design (FCCCD).
• The enrichment factor was obtained in the range 151–187 with RSDs ≤ 6.0%.

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.