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Sequential Injection Analysis of Ampicillin in Pharmaceuticals by Using Potentiometric Detectors Based on PVC and Sol-Gel Membranes

“…The experiments were performed in solutions with the ionic strength adjusted with the 5.0 × 10 -2 mol·l -1 dihydrogenphosphate solution when the PVC membranes were evaluated or with the 1.0 × 10 -2 mol·l -1 HMES solution in the case of sol-gel membranes. From the data, presented in Table 1, it is possible to affirm that both types of ampicillinate selective electrodes constructed in this work, using the same ionophore, presented similar or better slopes, reproducibilities, response times and practical limits of detection than those reported by other authors [13][14][15][16]. In spite of having better reproducibility and similar response time, the sol-gel membrane electrode showed narrower linear concentration range and shorter life time when compared with that obtained with PVC membrane electrode.…”

“…The results showed in Table 1 were obtained after two determinations performed with three electrodes and reveal that the developed electrodes were fairly selective to ampicillinate over other anions, being their selectivity coefficients similar or better than those obtained by other authors [13,16]. Regarding the Hofmeister selectivity pattern of the classical liquid ion-exchanger, the developed PVC and sol-gel membranes exhibited different selectivity sequences from that one as previously demonstrated when the same metalloporphyrin had been used to construct other anion selective membrane electrodes, namely carboxylic ions [2,4,27] obtained.…”

“…Potentiometric determination of ampicillin has been initially carried out by using ISEs sensitive to ampicillinate with membranes based on different ionophores such as: quaternary ammonium salts [13,14], ampicillin-phosphotungstate ion pair [15] and azacompounds and metal phtalocyanines [16]. The use of penicillinase have been proposed to construct enzyme electrodes which were applied to the determination of various -lactamic antibiotics [17,18].…”

Ion selective electrodes for penicillin-G based on Mn(III)TPP-Cl and their application in pharmaceutical formulations control by sequential injection analysis

“…Different methods are used for penicillin-G determination in pharmaceuticals, namely iodometric titrations and high-performance liquid chromatography (HPLC) with spectrophotometric detection [2], potentiometry and amperometry using biosensors [3,4], and even potentiometric ion selective electrodes based on anion exchangers [5]. Iodometric titrations are time-consuming and largely dependent on the operator, thus, providing less accurate results [2].…”

Determination of Benzylpenicillin, Ampicillin, and Carbenicillin by Paper Chromatography

“…Therefore, an urgent problem is the development of selective methods for analysis of antibiotics, as their adulteration is more frequent [7]. Titrimetric [8,9], spectrophotometric [10 313], and ionometric (with membrane ion-selective electrodes [14,15] and biosensors [16]) methods, as well as flow injection analysis [17], can be successfully used for quantitative determination of penicillin of a known chemical structure, but are unsuitable for identification of particular penicillins. According to recent studies, high-performance liquid chromatography (HPLC) can be successfully used for selective determination of penicillins [18,19].…”