Potentiometric and Optical Measurements for the Determination of Ephedrine

Calixarene based portable sensor for the direct assay of indiscriminate ephedrine content of weight loss herbal preparations

“…The study compares the performance of the developed sensor to that of the reported inner liquid membrane sensors ( Table 8 ). The sensor demonstrated a comparable slope, wider linear range, and a lower detection limit than most of the reported sensors (except for method VI 16 ). Exclusively, the sensor had the widest pH working range and was the only sensor designed for the determination of EPH in herbal samples.…”

“…Table 8 Comparison between the proposed potentiometric method and reported electrochemical methods for ephedrine assay Parameter Proposed method Reported electrochemical liquid membrane methods Method I 14 Method II 17 Method III 20 Method IV 19 Method V 18 Method VI 16 Linear range (M)…”

“…13 The relatively high polarity of EPH necessitated the use of either chromatographic columns with special chemistries or the addition of mobile phase modiers to retain EPH within the stationary phase and thereby enable the efficient chromatographic separation process. Furthermore, EPH was assayed in different pharmaceutical formulations and biological uids using PVC potentiometric sensors [14][15][16][17][18][19][20] but neither of them succeeds to determine EPH in herbal complex mixtures. Moreover, they relied on traditional liquid membranes with an inner lling solution that promote the transmembrane ux rather than the solid contact sensors which showed better sensitivities.…”

Electro-oxidation and adsorptive stripping voltammetric determination of ephedrine and pseudoephedrine at carboxylated multi-walled carbon nanotube-modified electrode

“…However, there are few reports in literature on the electrochemical properties of EP and PSE. [18][19][20][21][22][23][24] Carbon nanotubes (CNTs) have attracted enormous interest in recent years due to their high chemical stability, large surface area, unique electronic properties and relatively high mechanical properties. As electrode materials, CNTs can facilitate electron transfer between electroactive species and the electrode and provide a new means of electrode surface modification for designing new electrochemical sensors or biosensors.…”