scholarly journals Simultaneous determination of acesulfame-K, aspartame and stevioside in sweetener blends by ultraviolet spectroscopy with variable selection by sipls algorithm

2012 ◽  
Vol 31 (1) ◽  
pp. 17 ◽  
Author(s):  
Yang-Chun He ◽  
Sheng Fang ◽  
Xue-Jiao Xu
Keyword(s):  
Least Squares ◽  
Simultaneous Determination ◽  
Partial Least Squares ◽  
Spectroscopic Method ◽  
Relative Standard Error ◽  
Full Spectrum ◽  
Region Selection ◽  
Relative Standard ◽  
Selection Of

A chemometric-assisted UV absorption spectroscopic method is proposed for the simultaneous determination of acesulfame-K, aspartame and stevioside in raw powder mixtures of commercial sweeteners. The synergy interval partial least squares (siPLS) algorithm was applied to select the optimum spectral range and their combinations. The utilization of spectral region selection aims to construct better partial least squares (PLS) model than that established from the full-spectrum range. The results show that the siPLS algorithm can find out an optimized combination of spectral regions, yielding lower relative standard error of prediction (RSEP) and root mean square error of prediction (RMSEP), as well as simplifying the model. The RMSEP and RSEP obtained after selection of intervals by siPLS were 0.1330 μg·ml–1 and 1.50 % for acesulfame-K, 0.2540 μg·ml–1 and 1.64 % for aspartame, 1.4041 μg·ml–1 and 2.03 % for stevioside respectively. The recovery values range from 98.12 % to 101.88 % for acesulfame-K, 98.63 % to 102.96% for aspartame, and 96.38 % to 104.04 % for stevioside respectively.

scholarly journals Genetic Algorithms-Based Approach for Wavelength Selection in Simultaneous Spectrofluorimetric Determination of Ofloxacin and Riboflavin in biological samples by Partial Least-Squares

2019 ◽  
Vol 63 (4) ◽  
Author(s):  
Farah Assadian ◽  
Ali Niazi
Keyword(s):  
Least Squares ◽  
Simultaneous Determination ◽  
Partial Least Squares ◽  
Relative Standard Error ◽  
Good Reliability ◽  
Prediction Ability ◽  
Relative Standard ◽  
Orthogonal Signal Correction ◽  
Mean Square Errors

This study shows that genetic algorithm (GA) is a suitable method for selecting wavelengths for partial least squares (PLS) calibration of mixtures with almost identical spectra without loss of prediction capacity employing spectrofluorimetric method. A training set of mixtures containing different concentrations of ofloxacin (OFL) and riboflavin (B2) were prepared to be used as calibration set to check the prediction ability of GA-PLS models due to spectral overlapping of these constituents. Each model was validated using a validation set and then real samples were analyzed. Linear calibration curves were obtained in the 0.5-5.0 and 2.0-10.0 µg mL-1 range for ofloxacin and riboflavin, respectively. To preprocess the data matrices, the orthogonal signal correction (OSC) was used and the analysis results were statistically compared. The methods accuracy for simultaneous determination of ofloxacin and riboflavin, were evaluated by the root mean square errors of prediction (RMSEP) which were 0.0868 and 0.158 for ofloxacin and riboflavin, respectively, and relative standard error of prediction (RSEP) which were 2.738 and 2.846 for ofloxacin and riboflavin, respectively using OSC-GA-PLS models. This procedure allows the simultaneous determination of OFL and B2 in human urine and serum samples with good reliability of the determination.

scholarly journals Voltammetric determination of dopamine in the presence of ascorbic and uric acids using partial least squares regression: determination of dopamine in human urine and plasma

2009 ◽  
Vol 7 (3) ◽  
pp. 524-531 ◽  
Author(s):  
Morteza Bahram ◽  
Khalil Farhadi ◽  
Farzin Arjmand
Keyword(s):  
Least Squares ◽  
Partial Least Squares ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Limit Of Detection ◽  
Relative Standard Error ◽  
Carbon Electrode ◽  
Least Squares Regression ◽  
Relative Standard

AbstractA new differential pulse voltammetric method for dopamine determination at a bare glassy carbon electrode has been developed. Dopamine, ascorbic acid (AA) and uric acid (UA) usually coexist in physiological samples. Because AA and UA can be oxidized at potentials close to that of DA it is difficult to determine dopamine electrochemically, although resolution can be achieved using modified electrodes. Additionally, oxidized dopamine mediates AA oxidation and the electrode surface can be easily fouled by the AA oxidation product. In this work a chemometrics strategy, partial least squares (PLS) regression, has been applied to determine dopamine in the presence of AA and UA without electrode modification. The method is based on the electrooxidation of dopamine at a glassy carbon electrode in pH 7 phosphate buffer. The dopamine calibration curve was linear over the range of 1–313 μM and the limit of detection was 0.25 μM. The relative standard error (RSE %) was 5.28%. The method has been successfully applied to the measurement of dopamine in human plasma and urine.

Reflectance Near-Infrared Spectroscopic Method with a Chemometric Technique Using Partial Least Squares Multivariate Calibration for Simultaneous Determination of Chondroitin, Glucosamine, and Ascorbic Acid

2012 ◽  
Vol 95 (3) ◽  
pp. 724-732 ◽  
Author(s):  
Alaa El-Gindy ◽  
Khalid Abdel-Salam Attia ◽  
Mohammad Wafaa Nassar ◽  
Nasr M A El-Abasawy ◽  
Maisra Al-Shabrawi Shoeib
Keyword(s):  
Ascorbic Acid ◽  
Least Squares ◽  
Simultaneous Determination ◽  
Partial Least Squares ◽  
Near Infrared ◽  
Spectroscopic Method ◽  
Pharmaceutical Products ◽  
Calibration Model ◽  
Drug Concentrations

Abstract A reflectance near-infrared (RNIR) spectroscopy method was developed for simultaneous determination of chondroitin (CH), glucosamine (GO), and ascorbic acid (AS) in capsule powder. A simple preparation of the sample was done by grinding, sieving, and compression of the powder sample for improving RNIR spectra. Partial least squares (PLS-1 and PLS-2) was successfully applied to quantify the three components in the studied mixture using information included in RNIR spectra in the 4240–9780 cm–1 range. The calibration model was developed with the three drug concentrations ranging from 50 to 150% of the labeled amount. The calibration models using pure standards were evaluated by internal validation, cross-validation, and external validation using synthetic and pharmaceutical preparations. The proposed method was applied for analysis of two pharmaceutical products. Both pharmaceutical products had the same active principle and similar excipients, but with different nominal concentration values. The results of the proposed method were compared with the results of a pharmacopoeial method for the same pharmaceutical products. No significant differences between the results were found. The standard error of prediction was 0.004 for CH, 0.003 for GO, and 0.005 for AS. The correlation coefficient was 0.9998 for CH, 0.9999 for GO, and 0.9997 for AS. The highly accurate and precise RNIR method can be used for QC of pharmaceutical products.

scholarly journals The effect of pH on the simultaneous determination of Sulfamethoxazole and Trimethoprim by Ultraviolet Spectrophotometry and Multivariate Calibration

2017 ◽  
Vol 1 (2) ◽  
pp. 15-23
Author(s):  
Fabiana E.B. da Silva ◽  
Willian R.R. Almeida ◽  
Fávero R. Paula ◽  
Aline L.H. Müller ◽  
Érico M.M. Flores ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
High Performance ◽  
Multivariate Calibration ◽  
Analytical Techniques ◽  
Relative Standard Error ◽  
Uv Spectrophotometry ◽  
Calibration Data ◽  
Full Spectrum ◽  
Relative Standard

Analytical techniques based on Ultraviolet (UV) spectrophotometry are widely used in pharmaceutical analysis, because they are simple and inexpensive. The choice of pH is critical in the development of univariate methods for pharmaceutical quantitation by UV spectrophotometry since changes may modify the absorption spectrum profile. Similar to univariate methods by UV spectrophotometry changes in pH may influence the predictive ability of multivariate models, affecting the resultant analytical performance. We report herein on the influence of pH on the simultaneous determination of sulfamethoxazole (SMZ) and trimethoprim (TMP) in tablets using UV spectrophotometry and multivariate calibration. Data were recorded using a UV spectrophotometer in the wavelength range of 200 to 350 nm. The experimental matrix was constructed using 36 synthetic samples of SMZ-TMP mixtures. The concentration ranges used for the investigation were 14.0 to 26.0 mg L-1 for SMZ and 2.8 to 5.2 mg L-1 for TMP. The Partial Least Squares (PLS) regression models were generated with full-spectrum and multiple pH levels. At pH 4.3, lower values of relative standard error of prediction (RSEP %) for SMZ (1.83) and TMP (1.13) were obtained. The PLS model at pH 4.3 was used for the quantification of real samples (tablets obtained from 13 different manufacturers) and the results were compared with conventional procedures using high performance liquid chromatography (HPLC). 

Simultaneous spectrophotometric determination of minoxidil and tretinoin by the H-point standard addition method and partial least squares

2009 ◽  
Vol 63 (3) ◽  
Author(s):  
Maryam Bordbar ◽  
Ali Yeganeh-Faal ◽  
Jahanbakhsh Ghasemi ◽  
Mohammad Ahari-Mostafavi ◽  
Nahid Sarlak ◽  
...  
Keyword(s):  
Least Squares ◽  
Partial Least Squares ◽  
Standard Addition ◽  
Partial Least Square ◽  
Least Square ◽  
Standard Addition Method ◽  
Relative Standard Error ◽  
Addition Method ◽  
Relative Standard

AbstractA simple, sensitive and selective spectrophotometric method for simultaneous determination of tretinoin and minoxidil using partial least square (PLS) calibration and H-point standard addition method (HPSAM) is described. The results of the H-point standard addition method show that minoxidil and tretinoin can be determined simultaneously with the concentration ratio of tretinoin to minoxidil varying from 2: 1 to 1: 33 in mixed samples. A partial least squares multivariate calibration method for the analysis of binary mixtures of tretinoin and minoxidil was also developed. The total relative standard error for applying the PLS method to eleven synthetic samples in the concentration range of 0–10 μg mL−1 tretinoin and 0–32 μg mL−1 minoxidil was 2.59 %. Both proposed methods (PLS and HPSAM) were also successfully applied in the determination of tretinoin and minoxidil in several synthetic pharmaceutical solutions.

Simultaneous determination of methylxanthines in coffees and teas by UV-Vis spectrophotometry and partial least squares

2003 ◽  
Vol 493 (1) ◽  
pp. 83-94 ◽  
Author(s):  
Leticia López-Martı́nez ◽  
Pedro Luis López-de-Alba ◽  
Rosalinda Garcı́a-Campos ◽  
Luis M De León-Rodrı́guez
Keyword(s):  
Least Squares ◽  
Simultaneous Determination ◽  
Partial Least Squares
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