scholarly journals Simultaneous determination of procaine hydrochloride, procainamide hydrochloride and lidocaine by molecular absorption spectrometry

Author(s):  
Nicoleta Mirela Marin ◽  
Gheorghe Batrinescu ◽  
Mihai Nita-Lazar ◽  
Luoana Florentina Pascu ◽  
Carol Blaziu Lehr

Two spectrometric methods have been developed for quantitative simultaneous determination of procaine hydrochloride (PH·HCl), procainamide hydrochloride (PHA·HCl) and lidocaine (Lid) from synthetic mixture. The methods employed are first derivative spectrometry, using zero crossing method and multicomponent analysis which is based on the additivity law. Using first derivative spectrometry, the wavelength selected for the quantitative determination of PH·HCl was 237 nm for Lid was 242 nm and for PHA·HCl was 290 nm in mixture. The method is linear when the concentration ranged between 6.62-9.93 μg/mL for PH·HCl, 6.43-9.64 for PHA·HCl and 5.56-8.35 for Lid. The multicomponent analysis is a direct method and involves the absorbance measurements of at three different wavelengths. The molar absorption coefficients values were calculated at each wavelength and the concentration of PH·HCl, PHA·HCl and Lid from mixture was determined by solving matrix using Cramer's rule. The recovery of each compound in mixture was calculated and it is 101.4 % for PH·HCl, 100.4 % for PHA·HCl and 98.4 % for Lid.

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Shilan A. Omer ◽  
Nabil A. Fakhre

In this study, three simple and accurate spectrophotometric methods for simultaneous determination of pyriproxyfen and chlorothalonil residues in cucumbers and cabbages grown in experimental greenhouse were studied. The first method was based on the zero-crossing technique measurement for first and second derivative spectrophotometry. The second method was based on the first derivative of the ratio spectra. However, the third method was based on mean centering of ratio spectra. These procedures lack any previous separation steps. The calibration curves for three spectrophotometric methods are linear in the concentration range of 1–30 μg·mL−1 and 0.5–7 μg·mL−1 for pyriproxyfen and chlorothalonil successively. The recoveries ranged from 82.12–97.40% for pyriproxyfen and 81.51–97.04% for chlorothalonil with relative standard deviations less than 4.95% and 5.45% in all instances for pyriproxyfen and chlorothalonil, respectively. The results obtained from the proposed methods were compared statistically by using one-way ANOVA, and the results revealed there were no significant differences between ratio spectra and mean centering methods with the zero-crossing technique. The proposed methods are successfully applied for the simultaneous estimation of the residue of both pesticides in cucumber and cabbage samples.


2003 ◽  
Vol 86 (2) ◽  
pp. 241-245 ◽  
Author(s):  
M Inés Toral ◽  
Andrés Tassara ◽  
César Soto ◽  
Pablo Richter

Abstract A simple and fast method was developed for the simultaneous determination of dapsone and pyrimethamine by first-order digital derivative spectrophotometry. Acetonitrile was used as a solvent to extract the drugs from the pharmaceutical formulations, and the samples were subsequently evaluated directly by digital derivative spectrophotometry. The simultaneous determination of both drugs was performed by the zero-crossing method at 249.4 and 231.4 nm for dapsone and pyrimethamine, respectively. The best signal-to-noise ratio was obtained when the first derivative of the spectrum was used. The linear range of determination for the drugs was from 6.6 × 10−7 to 2.0 × 10−4 and from 2.5 × 10−6 to 2.0 × 10−4 mol/L for dapsone and pyrimethamine, respectively. The excipients of commercial pharmaceutical formulations did not interfere in the analysis. Chemical and spectral variables were optimized for determination of both analytes. A good level of repeatability, 0.6 and 1.7% for dapsone and pyrimethamine, respectively, was observed. The proposed method was applied for the simultaneous determination of both drugs in pharmaceutical formulations.


2013 ◽  
Vol 643 ◽  
pp. 43-46
Author(s):  
Yang Wang ◽  
Tian Tian ◽  
Lu Wang ◽  
Xiao Ya Hu

A simple, sensitive and quick assay to simultaneously determine lomefloxacin (LFLX) and ciprofloxacin (CPLX) had been developed by using zero-crossing first derivative constant wavelength synchronous spectrofluorimetry. Due to their similar molecule structures, it was difficult to analysis and determine LFLX and CPLX simultaneously by conventional fluorometry. In order to improve the sensitivity, aluminium ion was used to significantly enhance their endogenous fluorescent intensity. The different experimental parameters affecting the synchronous fluorescence intensity of the two fluoroquinolone drugs were carefully studied and optimized. The proposed method was successfully applied for the determination of the two drugs in milk samples.


2001 ◽  
Vol 84 (1) ◽  
pp. 37-42 ◽  
Author(s):  
M Ines Toral ◽  
Nelson Lara ◽  
Pablo Richter ◽  
Andres Tassara ◽  
A E Tapia ◽  
...  

Abstract A direct, simple, and practical first-derivative spectrophotometric method is described for simultaneous determination of ascorbic acid and acetylsalicylic acid. The effects of the solvent, excipients, and spectral variables on the analytical signal were investigated. The drugs were determined simultaneously with a 0.01M methanolic hydrochloric acid solution as the solvent, and the signals were evaluated directly by using the zero-crossing method at 245.0 and 256.0 nm for acetylsalicylic acid and ascorbic acid, respectively. The method allows the simultaneous determinations of acetylsalicylic acid and ascorbic acid in the ranges of 6.6 × 10−6 to 1.5 × 10−4M and 3.4 × 10−6 to 2.0 × 10−4M, respectively, with standard deviation of <2.0%. The proposed method was applied to determinations of these drugs in tablets.


Author(s):  
Mahesh Attimarad ◽  
Muhammad Shahzad Chohan ◽  
Abdulmalek Ahmed Balgoname

Simple, fast, and precise reversed-phase (RP)-high-performance liquid chromatography (HPLC) and two ecofriendly spectrophotometric methods were established and validated for the simultaneous determination of moxifloxacin HCl (MOX) and flavoxate HCl (FLX) in formulations. Chromatographic methods involve the separation of two analytes using an Agilent Zorbax SB C18 HPLC column (150 mm × 4.6 mm; 5 µm) and a mobile phase consisting of phosphate buffer (50 mM; pH 5): methanol: acetonitrile in a proportion of 50:20:30 v/v, respectively. Valsartan was used as an internal standard. Analytes were monitored by measuring the absorbance of elute at 299 nm for MOX and 250 nm for FLX and valsartan. Two environmentally friendly spectrophotometric (first derivative and ratio first derivative) methods were also developed using water as a solvent. For the derivative spectrophotometric determination of MOX and FLX, a zero-crossing technique was adopted. The wavelengths selected for MOX and FLX were −304.0 nm and −331.8 nm for the first derivative spectrophotometric method and 358.4 nm and −334.1 nm for the ratio first-derivative spectrophotometric method, respectively. All methods were successfully validated, as per the International Conference on Harmonization(ICH) guidelines, and all parameters were well within acceptable ranges. The proposed analytical methods were successfully utilized for the simultaneous estimation of MOX and FLX in formulations.


2005 ◽  
Vol 88 (4) ◽  
pp. 1126-1134 ◽  
Author(s):  
Khadiga M Kelani

Abstract A ratio-spectra zero-crossing first-derivative spectrophotometric method and 2 chemometric methods have been used for the simultaneous determination of ternary mixtures of caffeine (A), 8-chlorotheophylline (B), and chlorphenoxamine hydrochloride (C) in bulk powder and dosage forms. In the ratio-spectra zero-crossing first-derivative spectrophotometric technique (1DD), calibration curves were linear in the range of 4–20 μg/mL for A, B, and C (r = 0.9992, 0.9994, and 0.9976, respectively). The measurements were carried out at 212, 209.2, and 231.4 nm for A, B, and C, respectively. The detection limits for A, B, and C were calculated to be 0.24, 0.34, and 0.13 μg/mL, and the percentage recoveries were 99.1 ± 0.89, 100.1 ± 0.95, and 100.1 ± 1.0, respectively. Two chemometric methods, namely, the partial least-squares (PLS) model and the principal component regression (PCR) model, were also used for the simultaneous determination of the 3 drugs in the ternary mixture. A training set consisting of 15 mixtures containing different ratios of A, B, and C was used. The concentration used for the construction of the PLS and PCR models varied between 4 and 25 μg/mL for each drug. These models were used after their validation for the prediction of the concentrations of A, B, and C in mixtures. The detection limits for A, B, and C were calculated to be 0.13, 0.15, and 0.14 μg/mL, respectively, and the percent recoveries were found to be 99.8 ± 0.96, 99.9 ± 0.94, and 99.9 ± 1.18, respectively, for both methods. The 3 proposed procedures are rapid, simple, sensitive, and accurate. No preliminary separation steps or resolution equations are required; thus, they can be applied to the simultaneous determination of the 3 drugs in commercial tablets and suppositories or in quality-control laboratories.


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