Electrochemical characterization of simvastatin by abrasive stripping and square-wave voltammetry

Critical analysis of analytical techniques developed for statins in biological fluids, environmental and fermentation samples

Statins are the most prescribed drug for regulating the high cholesterol level in the blood, which can lead to severe complications, such as cardiovascular diseases and other health complications. A wide range of analytical techniques have been employed for the quantification of statins from various origins, including fermentation derived (lovastatin, pravastatin, and compactin), semi-synthetic (simvastatin), and synthetic (atorvastatin, rosuvastatin, and fluvastatin) routes. The presence of more than one structural form and structural analogue generated in the biosynthesis pathway, as well as reaction intermediates and macromolecules in the clinical sample, complicates the quantification of statins. Furthermore, significant concentrations of statins in environmental samples pose serious health and ecology hazards, and estimating statins in those diluted samples is extremely difficult. On the other hand, the: cost, accurate estimation of the desired one from other structural forms, sample complexity, time, limits of detection and quantification, were major criteria distinguishing the usability of each technique. As a result, the current manuscript focuses on analytical techniques such as molecular spectroscopy (normal and derivatives UV-Visible spectrophotometer), chromatography (TLC, HP-TLC, HPLC, GC, swing column, micellar, and supercritical fluid), mass spectroscopy (HPLC-MS/MS and GC-MS/MS), sequential flow injection, capillary electrophoresis, and cyclic voltammetry, as well as their: optimal operating conditions, limits of detection and quantification, advancements, and limitations. Furthermore, various online and offline sample preparations (precipitation, solid phase extraction, liquid-liquid extraction, and micellar extraction) have been highlighted as an essential pretreatment technique to avoid the interference caused by structural analogues and other macromolecules. The greener and more sustainable concepts used in analytical approaches for the quantification statins are also highlighted with current advancements.

Electroanalytical chemistry for the analysis of solids: Characterization and classification (IUPAC Technical Report)

Solid state electroanalytical chemistry (SSEAC) deals with studies of the processes, materials, and methods specifically aimed to obtain analytical information (quantitative elemental composition, phase composition, structure information, and reactivity) on solid materials by means of electrochemical methods. The electrochemical characterization of solids is not only crucial for electrochemical applications of materials (e.g., in batteries, fuel cells, corrosion protection, electrochemical machining, etc.) but it lends itself also for providing analytical information on the structure and chemical and mineralogical composition of solid materials of all kinds such as metals and alloys, various films, conducting polymers, and materials used in nanotechnology. The present report concerns the relationships between molecular electrochemistry (i.e., solution electrochemistry) and solid state electrochemistry as applied to analysis. Special attention is focused on a critical evaluation of the different types of analytical information that are accessible by SSEAC.

Estimation of antioxidative properties of tea leaves by abrasive stripping electrochemistry using paraffin-impregnated graphite electrode

Electrooxidation potentials of powdered green and black teas were determined by abrasive stripping voltammetry. A circular surface of paraffin-impregnated graphite rod was contaminated with tea microparticles and used as a chemically prepared working electrode in square-wave voltammetric experiments. The responses are ascribed to electrooxidation of flavanols in teas. Low oxidation potentials of some green teas were observed. An advantage of the proposed method is that no extraction of electroactive components is necessary.