scholarly journals Three Different Spectrophotometric Methods for Simultaneous Determination of Pyriproxyfen and Chlorothalonil Residues in Cucumber and Cabbage Samples

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.

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Shilan A. Omer ◽  
Nabil A. Fakhre

Three simple precise and accurate spectrophotometric methods are developed for simultaneous determination of ternary mixtures of carboxin, chlorpyrifos, and tebuconazole residues in cabbage grown in the experimental field. The first method is a double divisor-ratio spectra derivative that relies on the derivative of ratio spectra and attained through dividing the absorption spectra of the ternary mixture by the sum of standard spectrum of a mixture of two from three components, using methanol as a solvent and measuring CAR at 242 nm, CHL at 236 nm, 276 nm, and 300 nm, and TEB at 226 nm. The second method is a successive derivative of ratio spectra which determined CAR at 256 nm and 258 nm, CHL at 290 nm and 292 nm, and TEB at 226 nm and 228 nm. The third method is a mean centering of ratio spectra where CAR, CHL, and TEB were measured at 306 nm, 280 nm, and 240 nm, respectively. These procedures do not involve any previous separation. The extraction of analytes was carried out by using acetonitrile, and the procedure of purification was fulfilled by dispersive solid-phase extraction with a primary-secondary amine (PSA). The proposed methods showed excellent linearity range for three spectrophotometric methods over the concentration ranges of 1–30 μg/mL, 1–50 μg/mL, and 1–45 μg/mL for carboxin, chlorpyrifos, and tebuconazole, respectively. The analytical characteristics such as detection limit, determination limit, relative standard deviation, and accuracy of the three methods were performed. The limits of detection were in the range of 0.153–0.260 μg/mL for carboxin, 0.137–0.272 μg/mL for chlorpyrifos, and 0.109–0.205 μg/mL for tebuconazole with limits of quantification lower than 0.790, 0.824, and 0.621 μg/mL for CAR, CHL, and TEB, respectively. The recoveries ranged from 87.02% to 94.53% for carboxin, 92.32% to 108.53% for chlorpyrifos, and 87.19% to 98.00% for tebuconazole with relative standard deviations less than 5.91%, 5.99%, and 5.53% in all instances for carboxin, chlorpyrifos, and tebuconazole, respectively. The results obtained from the proposed methods were compared statistically by using one-way ANOVA, and the results revealed that there were no significant differences between three different spectrophotometric methods. The suggested methods can be applied with great success to the simultaneous estimation of carboxin, chlorpyrifos, and tebuconazole residues in cabbage samples.


Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6160
Author(s):  
Mahesh Attimarad ◽  
Katharigatta N. Venugopala ◽  
Bandar E. Al-Dhubiab ◽  
Rafea Elamin Elgack Elgorashe ◽  
Sheeba Shafi

Three rapid, accurate, and ecofriendly processed spectrophotometric methods were validated for the concurrent quantification of remogliflozin (RGE) and vildagliptin (VGN) from formulations using water as dilution solvent. The three methods developed were based on the calculation of the peak height of the first derivative absorption spectra at zero-crossing points, the peak amplitude difference at selected wavelengths of the peak and valley of the ratio spectra, and the peak height of the ratio first derivative spectra. All three methods were validated adapting the ICH regulations. Both the analytes showed a worthy linearity in the concentration of 1 to 60 µg/mL and 2 to 90 µg/mL for VGN and RGE, respectively, with an exceptional regression coefficient (r2 ≥ 0.999). The developed methods demonstrated an excellent recovery (98.00% to 102%), a lower percent relative standard deviation, and a relative error (less than ±2%), confirming the specificity, precision, and accuracy of the proposed methods. In addition, validated spectrophotometric methods were commendably employed for the simultaneous determination of VGN and RGE from solutions prepared in the laboratory and the formulation. Hence, these methods can be utilized for the routine quality control study of the pharmaceutical preparations of VGN and RGE in pharmaceutical industries and laboratories. The ecofriendly nature of the anticipated spectrophotometric procedures was confirmed by the evaluation of the greenness profile by a semi-quantitative method and the quantitative and qualitative green analytical procedure index (GAPI) method.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Fatma Turak ◽  
Mithat Dinç ◽  
Öznur Dülger ◽  
Mahmure Ustun Özgür

Four simple, rapid, and accurate spectrophotometric methods were developed for the simultaneous determination of two food colorants, Carmoisine (E122) and Ponceau 4R (E124), in their binary mixtures and soft drinks. The first method is based on recording the first derivative curves and determining each component using the zero-crossing technique. The second method uses the first derivative of ratio spectra. The ratio spectra are obtained by dividing the absorption spectra of the binary mixture by that of one of the components. The third method, derivative differential procedure, is based on the measurement of difference absorptivities derivatized in first order of solution of drink samples in 0,1 N NaOH relative to that of an equimolar solution in 0,1 N HCl at wavelengths of 366 and 451 nm for Carmoisine and Ponceau 4R, respectively. The last method, based on the compensation method is presented for derivative spectrophotometric determination of E122 and E124 mixtures with overlapping spectra. By using ratios of the derivative maxima, the exact compensation of either component in the mixture can be achieved, followed by its determination. These proposed methods have been successfully applied to the binary mixtures and soft drinks and the results were statistically compared with the reference HPLC method (NMKL 130).


2001 ◽  
Vol 84 (6) ◽  
pp. 1745-1750 ◽  
Author(s):  
Atanasse Coly ◽  
Jean-Jacques Aaron

Abstract First-derivative photochemically induced spectrofluorimetry (PIF-1D) is applied to the simultaneous determination of binary mixtures of 4 sulfonylurea herbicides in aqueous micellar samples. Synthetic binary mixtures of sulfometuronmethyl with chlorsulfuron, metsulfuron-methyl, and 3-rimsulfuron, respectively, are well resolved by using the zero-crossing point procedure. PIF-1D allows the determination of binary mixtures of these herbicides with linear dynamic ranges over about 2 orders of magnitude, limits of detection between 0.5 and 52 ng/mL, and relative standard deviations within 0.3–2.9%. Application to the determination of binary mixtures of these herbicides in spiked tap water samples yielded satisfactory recoveries (90–117%).


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Shahabuddin N. Alvi ◽  
Mehul N. Patel ◽  
Prakash B. Kathiriya ◽  
Bhavna A. Patel ◽  
Shraddha J. Parmar

Two simple, accurate, and precise UV derivative spectrophotometric methods for the simultaneous determination of Prasugrel and Aspirin in synthetic mixture form have been developed. The first method involves measurement of second order derivative spectra of Prasugrel and Aspirin. The zero crossing wavelengths 267.62 nm and 252.40 nm were selected for estimation of Prasugrel and Aspirin, respectively. In the second method, the first order derivatives of ratio spectra were calculated and used for the determination of Prasugrel and Aspirin by measuring the peak intensity at 268 nm and 290 nm, respectively. The methods were validated as per the ICH guideline Q2 (R1). Beer’s law is followed in the range of 5–45 μg/mL for Prasugrel and 25–150 μg/mL for Aspirin by second order derivative method and 6–22 μg/mL for Prasugrel and 45–165 μg/mL for Aspirin by ratio first order derivative method. The recovery studies confirmed the accuracy of the methods. Relative standard deviations for repeatability and inter- and intraday assays were less than 2%. Hence, the described derivative spectrophotometric methods are simple, accurate, precise, and excellent alternatives to sophisticated chromatographic techniques and can be potentially used for the simultaneous determination of Prasugrel and Aspirin in combined dosage form.


Author(s):  
Hemesh Gadiya ◽  
Monika Maheshwari ◽  
Ashok Dashora

Objective: The objective of this research was to develop and validate a simple ultraviolet (UV) spectrophotometric method for simultaneous determination of sildenafil citrate and dapoxetine hydrochloride in a pharmaceutical formulation.Methods: Two simple UV spectrophotometric methods have been developed for simultaneous determination of sildenafil citrate and dapoxetine hydrochloride. For both methods, stock solutions were prepared in methanol followed by the further required dilutions with methanol. Proposed dual-wavelength method and ratio derivative method, the wavelength of maximum absorption for sildenafil citrate and dapoxetine hydrochloride was 292 nm and 231 nm, respectively.Results: In both methods, the linearity range lies between 10 and 60 μg/ml for sildenafil citrate and 2–12 μg/mL for dapoxetine hydrochloride with their respective wavelengths. By dual-wavelength method, the percentage of sildenafil citrate and dapoxetine hydrochloride was found to be 101.3% and 100.3%, respectively.Conclusion: Result obtained in this research work clearly indicated that both these methods were found to be accurate, precise, stable, and robust as indicated by low values of percentage relative standard deviation. Thus, the present study gives an excellent method for the determination of both the drugs in combined tablet formulation.


2013 ◽  
Vol 96 (6) ◽  
pp. 1377-1386 ◽  
Author(s):  
Fatma Turak ◽  
Mahmure Ustun Ozgur

Abstract Four simple, rapid, sensitive, and accurate spectrophotometric methods were developed for the simultaneous determination of Allura Red (AR) and Ponceau 4R (P) without previous chemical separation. The first method, derivative spectrophotometry, depends on first derivative spectrophotometry with zero-crossing and peak-to-base measurement. The second method, derivative ratio spectrophotometry, uses the first derivative of the ratio spectra. The ratio spectra are obtained by dividing the absorption spectra of a binary mixture by that of one of the components. The third method, differential derivative spectrophotometry, is based on the measurement of the difference absorptivities derivatized in the first order of a sample extract in 0.1 M NaOH relative to that of an equimolar solution in 0.1 M HCI. The fourth method, based on the compensation technique, is presented for the derivative spectrophotometric determination of binary mixtures with overlapping spectra by using ratios of the derivative maximum or minimum; the exact compensation of either component in the mixture can be achieved, followed by its determination. All the proposed methods were successfully applied to the determination of the colorants in their laboratory mixtures and granulated drinks without any interference by the ingredients. AR and P showed good linearity, with regression coefficients of 0.9994–0.9999. The LOD and LOQ values ranged from 0.059 to 0.102 and 0.198 to 0.341 μg/mL, respectively. The intraday and interday precision tests produced good RSD values (<1.37%); recoveries ranged from 98.75 to 100.37% for all four methods. The common ingredients and additives did not interfere in the AR and P determination. The results of the proposed methods were statistically compared with the results of an HPLC method given in the literature (Nordic Committee on Food Analysis; NMKL 130) at the 95% confidence level by Student's t-test and the variance ratio F-test. No statistically significant difference was found among these methods.


Author(s):  
Hemesh Gadiya ◽  
Monika Maheshwari ◽  
Ashok Dashora

Objective: The objective of this research was to develop and validate a simple ultraviolet (UV) spectrophotometric method for simultaneous determination of sildenafil citrate and dapoxetine hydrochloride in a pharmaceutical formulation.Methods: Two simple UV spectrophotometric methods have been developed for simultaneous determination of sildenafil citrate and dapoxetine hydrochloride. For both methods, stock solutions were prepared in methanol followed by the further required dilutions with methanol. Proposed dual-wavelength method and ratio derivative method, the wavelength of maximum absorption for sildenafil citrate and dapoxetine hydrochloride was 292 nm and 231 nm, respectively.Results: In both methods, the linearity range lies between 10 and 60 μg/ml for sildenafil citrate and 2–12 μg/mL for dapoxetine hydrochloride with their respective wavelengths. By dual-wavelength method, the percentage of sildenafil citrate and dapoxetine hydrochloride was found to be 101.3% and 100.3%, respectively.Conclusion: Result obtained in this research work clearly indicated that both these methods were found to be accurate, precise, stable, and robust as indicated by low values of percentage relative standard deviation. Thus, the present study gives an excellent method for the determination of both the drugs in combined tablet formulation.


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.


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