UV-Visible First-Derivative Spectrophotometry Applied to an Analysis of a Vitamin Mixture

Abstract

A simple new experiment that uses UV-vis spectrophotometry to introduce undergraduate chemistry students to multicomponent analysis is presented and a method for the simultaneous determination of three vitamins using derivative spectrophotometry (zero-crossing method) is described. The methodology is simple and easy to apply and allows the determination of folic acid, pyridoxine, and thiamine over the concentration ranges 1.02-14.28, 1.00-16.00, and 6.00-20.00 μg mL-1, respectively. The resulting errors were nearly always less than 5%.

Stability‐indicating spectrofluorimetric method for the assay of riboflavin and photoproducts: Kinetic applications

“…Various fluorimetric methods have been developed for the assay of RF in pharmaceutical preparations, food materials and biological systems . The official United States Pharmacopeia (USP) assay of RF in pure form and in pharmaceutical preparations is based on the fluorimetric method ( λ ex = 444 nm, λ em = 530 nm) .…”

First Derivative Spectrophotometry for Simultaneous Determination of Iron and Calcium Using Bromopyrogallol Red.

“…Derivative spectra can be produced by processing the spectrophotometer output. The use of derivative spectra can increase the detection sensitivity of minor spectra features and reduce the error caused by the overlap of the analyte spectral band by interfering bands of other species in the sample [7]. Fig (3) and Fig (4) shows the 1 st -derivative absorption spectra of the complexes of Fe and Ca with BPR and of a mixture of both complexes respectively.…”

A didactic approach for quantification of diazepam tablets by UV spectrophotometry

“…This analytical tool is relevant in the pharmaceutical industry in areas such as quality control (2). Therefore, students of Pharmaceutical Sciences need to be familiar with this methodology (3)(4)(5)(6)(7)(8)(9)(10)(11). In this regard, this paper was designed to introduce the technique of ultraviolet spectroscopy to undergraduate students attending Pharmaceutical Organic Chemistry classes and describes a simple laboratory procedure for the quantitative assay of diazepam, a central nervous system depressant benzodiazepine, in commercial tablets.…”

“…Esta ferramenta analítica é útil na indústria farmacêutica em áreas como o controlo de qualidade (2). É assim fundamental que os estudantes de Ciências Farmacêuticas estejam familiarizados com esta metodologia (3)(4)(5)(6)(7)(8)(9)(10)(11). Neste sentido, este trabalho foi concebido para introduzir a técnica de espectroscopia de ultravioleta a estudantes que frequentam aulas de Química Orgânica Farmacêutica e descreve um procedimento laboratorial simples para o ensaio quantitativo de diazepam, uma benzodiazepina depressora do sistema nervoso central, em comprimidos comerciais.…”