Vierordt’s method

Multicomponent Analysis

1. Vierordt’s Method Azad H Alshatteri [email protected] Ph.D. candidate in Bioanalysis and bionanosensors

2. INTRODUCTION CALCULATION ADVANTAGE SHORTCOMING APPLICATION REFERENCE Vierordt’s method Simultaneous equation analysis is a multicomponent analysis. It is also known as Vierordt’s method. Multicomponent analysis has become one of the most appealing topics for analytical chemists recently, in fields of clinical chemistry, pharmaceutical drug analysis, pollution control, and extra. Different analytical techniques can be applied for multicomponent analysis. Including: spectrophotometry, chromatography, and electrophoresis. In my webinar, I will focus on using UV-VIS spectrometry for multicomponent analysis frequently. Since it is more applicable and most of the scientific works have been done by this technique.

3. INTRODUCTION CALCULATION ADVANTAGE SHORTCOMING APPLICATION REFERENCE There are many UV spectrophotometric methods used in multicomponent analysis Derivative spectrophotometry Simultaneous equation analysis (Vierordt’s Method) Dual wavelength In this webinar, I am trying to highlight of simultaneous equation analysis (Vierordt’s method).

4. INTRODUCTION CALCULATION ADVANTAGE SHORTCOMING APPLICATION REFERENCE Simultaneous equation analysis (Vierordt’s Method) If a sample contains two absorbing species (X and Y) each of them absorbs at the λ max of the other, it may be possible to determine the two species by the Vierordt’s method. The method depends on the fact that the absorbance of the mixture at any λ is the summation of the absorbance of X and Y species. Provided that no physical or chemical interaction occurs between the two components. It has been seen that UV/VIS absorption peaks are generally broad, so if there are two compounds, X and Y, in solution, it is likely that they will not be completely resolved from each other. That is, both X and Y contribute to the absorbance at most wavelengths. It is possible to calculate the concentrations of X and Y from a series of measurements.

5. INTRODUCTION CALCULATION ADVANTAGE SHORTCOMING APPLICATION REFERENCE Simultaneous equation analysis (Vierordt’s Method) Measurements must be made at a number of wavelengths equal to the number of components in the mixture. if there are two components, two wavelengths are needed. Four calibration curves need to be prepared: X at , X at , Y at , and Y at . All calibration curves should be blank corrected to pass through the origin. The absorbance of the sample mixture is measured at and at .  

6. INTRODUCTION CALCULATION ADVANTAGE SHORTCOMING APPLICATION REFERENCE Procedure The λ max value of each component is determined using its solution of suitable concentration The solutions of various concentrations of each component is prepared separately, and the Beer’s law is tested at respective λ max by plotting absorbance values vs. the concentration. This is a calibration curve of the given component at its λ max. The slope ( ɛb ) of the calibration curve is determined. Solutions of each component is measured at wavelengths chosen for other components and respective slopes are calculated. The absorbance values of mixture at each of the wavelengths are determined by the same pathlength cuvette. The measurements thus obtained are inserted in the following equations:

7. INTRODUCTION CALCULATION ADVANTAGE SHORTCOMING APPLICATION REFERENCE UV Spectra

8. INTRODUCTION CALCULATION ADVANTAGE SHORTCOMING APPLICATION REFERENCE Simultaneous equation analysis (Vierordt’s Method) Where Two equations can be written :   , C X , the concentration of X in the unknown , C Y , the concentration of Y in the unknown. , the slope of the calibration curve for X at λ 1 . , the slope of the calibration curve for X at λ 2 the slope of the calibration curve for Y at λ 1 , the slope of the calibration curve for Y at λ 2 , are the λ max of X and Y respectively .  

9. INTRODUCTION CALCULATION ADVANTAGE SHORTCOMING APPLICATION REFERENCE Simultaneous equation analysis (Vierordt’s Method) If we simultaneously solves the equations 1 and 2 Equations 3 and 4 give concentration of x and y in their mixture.   3 4

10. INTRODUCTION CALCULATION ADVANTAGE SHORTCOMING APPLICATION REFERENCE The advantage of Vierordt’s Method Avoiding prior separation techniques e.g. extraction, preconcentration of constituents, which cause to get more accurate result. Spectral data are readily acquired with ease. Wide applicability for organic and inorganic multicomponent. Typical limit of detection is with high selectivity. Multicomponent can be analyzed simultaneously. So, it is the time and cost effective method. It is green chemistry method because we do not use much solvents and we do not have byproducts as we have in traditional methods  

11. INTRODUCTION CALCULATION ADVANTAGE SHORTCOMING APPLICATION REFERENCE shortcoming ( requirements ) to apply simultaneous equation method: The λ max of two drugs should be reasonable different. There is no chemical interaction between the absorbing components. Each component act independently that is each one absorbs as if others are not present. They should obey Beers law at their wavelength maximum (λmax) if used in UV-VIS spectrophotometry . Two absorbing species (for example drug x and drug y), each of which should have some absorbance at λmax of others. 6. Interpretation of data is more complicate than traditional calibration curve.

12. INTRODUCTION CALCULATION ADVANTAGE SHORTCOMING APPLICATION REFERENCE New Simple Spectrophotometric Method for the Simultaneous Estimation of Paracetamol and Flupirtine Maleate in Pure and Pharmaceutical Dosage Form Applications of simultaneous equation method and derivative method for the determination of rabeprazole sodium and levosulpiride in pharmaceutical dosage form and dissolution samples Two different spectrofluorimetric methods for simultaneous determination of gemfibrozil and rosiglitazone in human plasma Application of different spectrophotometric methods for simultaneous determination of elbasvir and grazoprevir in pharmaceutical preparation Validation and application of Vierordt’s spectrophotometric method for simultaneous estimation of tamoxifen/coenzyme Q10 in their binary mixture and pharmaceutical dosage forms Simultaneous estimation of dutasteride and tamsulosin hydrochloride in tablet dosage form by Vierordt’s method

13. INTRODUCTION CALCULATION ADVANTAGE SHORTCOMING APPLICATION REFERENCE Simultaneous determination of Indigotin and Ponceau-4R in food samples by using Vierordt’s method, ratio spectra first order derivative and derivative UV spectrophotometry A comparative study of the ratio spectra derivative spectrophotometry, Vierordt’s method and high-performance liquid chromatography applied to the simultaneous analysis of caffeine and paracetamol in tablets Simultaneous Spectrophotometric Method for Determination of Emtricitabine and Tenofovir Disoproxil Fumarate in Three-Component Tablet Formulation Containing Rilpivirine Hydrochloride

14. INTRODUCTION CALCULATION ADVANTAGE SHORTCOMING APPLICATION REFERENCE [1] J. W. Robinson, E. S. Frame, and G. M. Frame II, Undergraduate Instrumental Analysis . 2014. [2] J. B. Ashie , “Study on Methods of Simultaneous Multi-Component Analysis.,” p. 101, 2008. [3] Giriraj, P., and T. Sivakkumar . "New simple spectrophotometric method for the simultaneous estimation of paracetamol and flupirtine maleate in pure and pharmaceutical dosage form."  International Journal of Spectroscopy  2014 (2014). [4] P. R. Shetty and D. D. Patil, “Applications of simultaneous equation method and derivative method for the determination of rabeprazole sodium and levosulpiride in pharmaceutical dosage form and dissolution samples,” J. Assoc. Arab Univ. Basic Appl. Sci. , vol. 15, no. 1, pp. 53–60, 2014, doi : 10.1016/j.jaubas.2013.05.005. [5] S. Venkatesan and N. Kannappan , “Simultaneous Spectrophotometric Method for Determination of Emtricitabine and Tenofovir Disoproxil Fumarate in Three-Component Tablet Formulation Containing Rilpivirine Hydrochloride,” Int. Sch. Res. Not. , vol. 2014, pp. 1–8, 2014, doi : 10.1155/2014/541727. [6] E. Dinç , “A comparative study of the ratio spectra derivative spectrophotometry, Vierordt’s method and high-performance liquid chromatography applied to the simultaneous analysis of caffeine and paracetamol in tablets,” J. Pharm. Biomed. Anal. , vol. 21, no. 4, pp. 723–730, 1999, doi : 10.1016/S0731-7085(99)00186-7.

15. INTRODUCTION CALCULATION ADVANTAGE SHORTCOMING APPLICATION REFERENCE [7] K. A. M. Attia, N. M. El- Abasawi , A. El- Olemy , and A. H. Abdelazim , “Application of different spectrophotometric methods for simultaneous determination of elbasvir and grazoprevir in pharmaceutical preparation,” Spectrochim . Acta - Part A Mol. Biomol . Spectrosc . , vol. 189, pp. 154–160, 2018, doi : 10.1016/j.saa.2017.08.026. [8] M. M. K. S. El-Din, K. A. M. Attia, M. W. I. Nassar, and M. M. Y. Kaddah , “Two different spectrofluorimetric methods for simultaneous determination of gemfibrozil and rosiglitazone in human plasma,” Talanta , vol. 82, no. 5, pp. 1708–1716, 2010, doi : 10.1016/j.talanta.2010.07.058. [9] E. S. El- Leithy and R. S. Abdel-Rashid, “Validation and application of Vierordt’s spectrophotometric method for simultaneous estimation of tamoxifen/coenzyme Q10 in their binary mixture and pharmaceutical dosage forms,” Asian J. Pharm. Sci. , vol. 11, no. 2, pp. 318–325, 2016, doi : 10.1016/j.ajps.2016.02.005. [10] S. Altinöz and S. Toptan , “Simultaneous determination of Indigotin and Ponceau-4R in food samples by using Vierordt’s method, ratio spectra first order derivative and derivative UV spectrophotometry,” J. Food Compos. Anal. , vol. 16, no. 4, pp. 517–530, 2003, doi : 10.1016/S0889-1575(03)00022-X. [11] S. Hansen, S. Pedersen- Bjergaard , and K. Rasmussen, Introduction to Pharmaceutical Chemical Analysis . 2011.