Optimization and validation of a method for the determination of caffeine, 8-chlorotheophylline and diphenhydramine by isocratic high-performance liquid chromatography

Barbas, Coral; Garcı́a, Antonia; Saavedra, Luis Celi; Castro, Mario

doi:10.1016/s0021-9673(99)01186-3

Cited by 52 publications

(30 citation statements)

References 5 publications

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“…7 The HPLC analysis was performed using a Shimadzu LC-10 VP equipped with an UV-Vis detector (SPD-10AV), a LC column (Phenomenex MAX-RP-C12, 250 mm x 4.6 mm, 4 µm), a manual injector (20 µL) and a pump (LC-10AD-VP). The mobile phase consisted of a mixture of acetonitrile and 0.01 mol L -1 H 3 PO 4 + triethylamine up to pH 2.8 (22:78, v/v).…”

Section: 20mentioning

confidence: 99%

“…Therefore, in some formulations containing DIM, 5,6 caffeine (CAF) is added in order to reduce the sedative effects of DIP. 7 To our knowledge, there is only one previous work which reported an analytical method for the simultaneous determination of DIP, CTP and CAF. The method is based on HPLC with UV-Vis detection.…”

Section: Introductionmentioning

confidence: 99%

“…The method is based on HPLC with UV-Vis detection. 7 Apart from this method, procedures which demonstrated the possibility of determination of two from the three target analytes were reported previously, such as DIM (DIP + CTP) by spectrophotometry, 8 by batch injection analysis (BIA), 9 and by HPLC-UV. 10 The possibility of determination of both CAF and DIP was demonstrated by spectrophotometry.…”

Section: Introductionmentioning

confidence: 99%

“…However, only a single method that allows the simultaneous determination of the three compounds was found in the literature. 7 Therefore, the development of an alternative analytical method is of great importance.…”

Section: Introductionmentioning

confidence: 99%

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Amperometric determination of 8-chlorotheophylline, caffeine, and diphenhydramine in a single run

Freitas¹,

Oliveira²,

Muñoz³

et al. 2017

Quim. Nova

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publicado na web em 15/05/2017 A simple method for simultaneous determination of 8-chlorotheophylline (CTP), caffeine (CAF), and diphenhydramine (DIP) using batch-injection analysis with multiple pulse amperometric detection (BIA-MPA) is reported. A sequence of three potential pulses (+1.10 V, +1.40 V, and +1.70 V) was applied to the boron-doped diamond working electrode with the acquisition of three distinct amperograms. CTP was detected selectively at +1.10 V, both CTP + CAF at +1.40 V and CTP + CAF + DIP at +1.70 V. The subtraction between the currents detected at the three potential pulses (with the use of correction factors) was the strategy used to achieve selectivity for the determination of CAF and DIP. The proposed method is simple, inexpensive, fast (120 injections h -1 ), presents good precision (RSD < 0.9%; n = 20), and adequate limits of detection (0.31, 0.49, and 0.76 µmol L -1 for CTP, CAF and DIP, respectively). The results obtained by BIA-MPA were similar to those found by high-performance liquid chromatography (95% confidence level).

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Section: 20mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Amperometric determination of 8-chlorotheophylline, caffeine, and diphenhydramine in a single run

Freitas¹,

Oliveira²,

Muñoz³

et al. 2017

Quim. Nova

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show abstract

“…Chromatographic methods have been used such as gas chromatography [6] and HPLC [7], and the necessity to ensure the quality of pharmaceutical polydrugs like diphenhydramine and consequently the safety and efficacy of the final marketed product has led to the development and evaluation of new techniques that reduce the time and cost of analysis such as capillary electrophoresis [8,9].…”

Section: Introductionmentioning

confidence: 99%

A dysprosium nanowire modified carbon paste electrode for determination of levodopa using fast Fourier transformation square-wave voltammetry method

Daneshgar

Norouzi

Ganjali

et al. 2009

Colloids and Surfaces B: Biointerfaces

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A new detection technique called the fast Fourier transform square-wave voltammetry (FFT SWV) is based on measurements of electrode admittance as a function of potential. The response of the detector (microelectrode) is fast, which makes the method suitable for most applications involving flowing electrolytes. The carbon paste electrode was modified by nanostructures to improve better sensivity. The redox property of Diphenhydramin was used for determination of it in human serum and urine samples. Synthesized dysprosium nanowires make more effective surface like nanotubes [1-4] so they are good candidates for using as a modifier for electrochemical reactions. The drug presented one irreversible oxidation peaks at 1080mV vs. Ag/ AgCl by modified Nanowire carbon paste electrode which produced high current and reduced the oxidation potential about 300mV. Furthermore, signalto-noise ratio has significantly increased by application of discrete fast Fourier Transform (FFT) method, background subtraction and two-dimensional integration of the electrode response over a selected potential range and time window. To obtain the much sensivity the effective parameters such as frequency, amplitude and pH was optimized. As a result, LOD of 4.0 ×10-11 mol l -1 and an LOQ of 8.0× 10 -11 mol l -1 were found for determination for Diphenhydramin. A good recovery was obtained for assay spiked urine samples and a good quantification of Diphenhydramin was achieved in a commercial formulation.

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Effect of solution pH and influence of water hardness on caffeine adsorption onto activated carbons

et al. 2014

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There has been little research into the effects of the water hardness and pH of surface waters on the adsorption of caffeine on activated carbons. The aim of this study was to determine the influence of these water characteristics on different activated carbons. Caffeine adsorption from the aqueous phase was studied using biomass derived activated carbons (DD: dende coco and BB: babassu coco) and a commercially available activate carbon (NO: Norit® GAC 1240 plus). The functionalized carbons in an inert atmosphere was also studied and were denominated DI, BI, NI. Results highlight the importance of pH in caffeine adsorption: the highest removals were obtained for pH 3.0 and decrease for higher pH. The adsorption isotherms obtained were fitted to the Freundlich and Langmuir models. Calcium and magnesium ions were adsorbed to a varied extent on the activated carbons. The hardness in solution decreased their adsorption due to a competition effect. KF and qm from the Freundlich equation linearly decreased with water hardness due to salt‐screened electrostatic repulsions between charged molecules. The amount adsorbed from deionized water was largest because there was no competition between inorganic ions and molecules.

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Optimization and validation of a method for the determination of caffeine, 8-chlorotheophylline and diphenhydramine by isocratic high-performance liquid chromatography

Cited by 52 publications

References 5 publications

Amperometric determination of 8-chlorotheophylline, caffeine, and diphenhydramine in a single run

Amperometric determination of 8-chlorotheophylline, caffeine, and diphenhydramine in a single run

A dysprosium nanowire modified carbon paste electrode for determination of levodopa using fast Fourier transformation square-wave voltammetry method

Effect of solution pH and influence of water hardness on caffeine adsorption onto activated carbons

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