The Application of CLS Algorithm in the Quantitative Analysis of Lime in Wheat Flour by NIR Spectroscopy

2012 ◽  
Vol 472-475 ◽  
pp. 1874-1880
Author(s):  
Dong Wang ◽  
Zhi Hong Ma ◽  
Li Gang Pan ◽  
Liu Zhao ◽  
Ping Han ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Wheat Flour ◽  
Limit Of Detection ◽  
External Validation ◽  
Peak Height ◽  
F Test ◽  
Area Model ◽  
Derivative Spectra ◽  
Peak Areas ◽  
Height Model

Classical least square (CLS) algorithm is applied in this thesis to develop the raw spectra corrected peak area model, the raw spectra corrected peak height model, the 2ndderivative spectra corrected peak area model and the 2ndderivative spectra corrected peak height model by NIR spectra data of the wheat flour samples with lime added in. The result indicated that the correlation coefficients of the 4 models are 0.9321, 0.9483, -0.9491 and -0.9482 respectively; the result of F-test indicated that a remarkable correlation exists between the specified values of lime in wheat flour and the the raw spectra corrected peak areas / heights or the 2ndderivative spectra corrected peak areas / heights, which indicated that CLS algorithm has a certain potential application in the quantitative analysis of lime in wheat flour by NIR spectra data. Meanwhile, the result of F-test indicated that a very remarkable correlation exists between the estimated and specified values both the calibration set and external validation set of the 4 models. The limit of detection of the 4 models are 4.83 %, 4.14 %, 4.14 % and 4.17 % respectively, which will be suitable for the rapid quality screening for the wheat flour in the market and will be of great importance to the quality screening of wheat flour in the market, guarantee of the customers' health and the design and manufacturing of the special NIR spectrometer.

Validated Stability Indicating HPTLC Method for the Estimation of Amoxapine in Different Stress Conditions

2019 ◽  
Vol 15 (3) ◽  
pp. 273-279
Author(s):  
Shweta G. Rangari ◽  
Nishikant A. Raut ◽  
Pradip W. Dhore
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Degradation Products ◽  
Analysis Data ◽  
Peak Height ◽  
Good Resolution ◽  
Stability Indicating ◽  
Limit Of Quantitation ◽  
Wide Range ◽  
Hptlc Method

Background:The unstable and/or toxic degradation products may form due to degradation of drug which results into loss of therapeutic activity and lead to life threatening condition. Hence, it is important to establish the stability characteristics of drug in various conditions such as in temperature, light, oxidising agent and susceptibility across a wide range of pH values.Introduction:The aim of the proposed study was to develop simple, sensitive and economic stability indicating high performance thin layer chromatography (HPTLC) method for the quantification of Amoxapine in the presence of degradation products.Methods:Amoxapine and its degraded products were separated on precoated silica gel 60F254 TLC plates by using mobile phase comprising of methanol: toluene: ammonium acetate (6:3:1, v/v/v). The densitometric evaluation was carried out at 320 nm in reflectance/absorbance mode. The degradation products obtained as per ICH guidelines under acidic, basic and oxidative conditions have different Rf values 0.12, 0.26 and 0.6 indicating good resolution from each other and pure drug with Rf: 0.47. Amoxapine was found to be stable under neutral, thermal and photo conditions.Results:The method was validated as per ICH Q2 (R1) guidelines in terms of accuracy, precision, ruggedness, robustness and linearity. A good linear relationship between concentration and response (peak area and peak height) over the range of 80 ng/spot to 720 ng/spot was observed from regression analysis data showing correlation coefficient 0.991 and 0.994 for area and height, respectively. The limit of detection (LOD) and limit of quantitation (LOQ) for area were found to be 1.176 ng/mL and 3.565 ng/mL, whereas for height, 50.063 ng/mL and 151.707 ng/mL respectively.Conclusion:The statistical analysis confirmed the accuracy, precision and selectivity of the proposed method which can be effectively used for the analysis of amoxapine in the presence of degradation products.

scholarly journals A A RAPID AND SENSITIVE RP-HPLC METHOD FOR THE QUANTITATIVE ANALYSIS OF EMPAGLIFLOZIN IN BULK AND PHARMACEUTICAL DOSAGE FORM

2019 ◽  
pp. 60-65
Author(s):  
MADHURIMA BASAK ◽  
Santhosh Reddy Gouru ◽  
Animesh Bera ◽  
Krishna veni Nagappan
Keyword(s):  
Quantitative Analysis ◽  
High Performance ◽  
Dosage Form ◽  
Limit Of Detection ◽  
Hplc Method ◽  
Reverse Phase ◽  
Pharmaceutical Dosage Form ◽  
Rp Hplc ◽  
Limit Of Quantitation ◽  
Bulk Drug

Objective: The present study aims at developing an accurate precise, rapid and sensitive Reverse Phase High-Performance Liquid Chromatography (RP-HPLC) method for assessing Empagliflozin in bulk drug and in the pharmaceutical dosage form. Methods: The proposed method employs a Reverse Phase Shim Pack C18 column (250 mm × 4.6 mm id; 5 µm) using a mobile phase comprising of acetonitrile and water in the ratio of 60:40 v/v flushed at a flow rate of 1 ml/min. The eluents were monitored at 223 nm. Results: Empagliflozin was eluted at a retention time of 5.417 min and established a co-relation co-efficient (R2>0.999) over a concentration ranging from 0.0495-100µg/ml. Percentage recovery was obtained between 98-102% which indicated that the method is accurate. The Limit of Detection (LOD) and Limit of Quantitation (LOQ) were found at 0.0125µg/ml and 0.0495µg/ml, respectively. Conclusion: An RP-HPLC method which was relatively simple, accurate, rapid and precise was developed and its validation was performed for the quantitative analysis of empagliflozin in bulk and tablet dosage form (10 and 25 mg) in accordance to International Conference of Harmonization (ICH) Q2 (R1) guidelines. The proposed method may aid in routinely analyzing empagliflozin in pharmaceuticals.

scholarly journals The Application of a Cadmium Reducer and a Diazotisation Reaction for the Determination of Nitrate and Nitrite in Tobacco / Über die Anwendung des Cadmium-Reduktors und der Diazotierung zur Bestimmung von Nitrat und Nitrit im Tabak

1965 ◽  
Vol 3 (2) ◽  
Author(s):  
U. Dölberg
Keyword(s):  
Quantitative Analysis ◽  
Reduction Method ◽  
Limit Of Detection ◽  
Nitrate And Nitrite ◽  
Inferior Limit

AbstractNitrate is reduced by means of a cadmium reducer and spectrophotometrically determined in the form of nitrite by a diazotisation reaction. The results obtained by application of the described method to tobacco extracts correspond well to those resulting from the earlier described dimethylphenol procedure. Owing to its better sensitivity and specifity the reduction method is particularly suitable for the quantitative analysis of smallest amounts of nitrate. Quantities of 0.03 % of nitrate can be determined without difficulties. The inferior limit of detection is 0.001 %.

METHOD DEVELOPMENT AND VALIDATION FOR THE SIMULTANEOUS ESTIMATION OF THYMOL AND EUGENOL BY USING RP-HPLC IN PURE AND IN EMULGEL FORMULATION

INDIAN DRUGS ◽  
2021 ◽  
Vol 58 (07) ◽  
pp. 59-65
Author(s):  
Vinita C. Patole ◽  
Shilpa P. Chaudhari ◽  
Keyword(s):  
High Performance ◽  
Method Development ◽  
Limit Of Detection ◽  
Hplc Method ◽  
Simultaneous Estimation ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
Peak Areas ◽  
80 A 20 ◽  
Development And Validation

An attempt was made to develop a simple, selective, rapid and precise high-performance liquid chromatography (HPLC) method for simultaneous estimation of thymol and eugenol. Analysis was performed on a C18 column with the mobile phase consisting of solvent %A (water) and solvent %B (acetonitrile) with the following gradient: 0–1 min, 80 % A, 20 % B; 1–7 min, 40 % A and 60 % B; 7–12 min, 10 % A and 90 % B; and 12–15min, 80 % A and 20 % B at a flow rate of 0.6 mL/min. The compounds were well separated on a Thermo Scientific Hypersil BDS RP C18 column (4.6 mm × 150 mm, dp = 5 µm) and ultraviolet detection at 280 nm. The retention times of eugenol and thymol were 10.5 min and 11.6 min, respectively. Validation of the proposed method was carried out according to the guidelines of the International Council on Harmonization (ICH). The linearity of the method is good for thymol and eugenol over the concentration range of 1–50 ppm, and the r 2 values were 0.9996 for both thymol and eugenol. The calculated limit of detection (LOD) value was 0.5ppm and the limit of quantification (LOQ) value was 1ppm for both the analytes. The intra and interday relative standard deviation (RSD) of the retention time and peak areas was less than 3 %.The established method was appropriate, and the two markers were well resolved, enabling efficient quantitative analysis of thymol and eugenol.

Gas Chromatographic Profile Analysis of Basic Nitrogen-Containing Aromatic Compounds (Azaarenes) in High Protein Foods

1986 ◽  
Vol 69 (3) ◽  
pp. 537-541
Author(s):  
Gernot Grimmer ◽  
Klaus-Werner Naujack
Keyword(s):  
Aromatic Compounds ◽  
Limit Of Detection ◽  
Profile Analysis ◽  
Collaborative Study ◽  
Internal Standard ◽  
Exchange Chromatography ◽  
Basic Nitrogen ◽  
Chromatographic Profile ◽  
Polycyclic Aromatic ◽  
Peak Areas

Abstract A method is described for the determination of basic nitrogen-containing polycyclic aromatic compounds (N-PACs, azaarenes) in meat. The enrichment procedure includes liquid-liquid partition (dimethylformamide-water-cyclohexane), extraction of N-PACs by sulfuric acid, reextraction after neutralization by cyclohexane or, alternatively, by nonadsorbing ion exchange chromatography. Further purification is performed by column chromatography on Sephadex LH20 using a dosed system to avoid sample contamination by laboratory pollutants. N-PACs are analyzed by capillary gas chromatography and measured by comparing to the corresponding peak areas of an internal standard (e.g., lO-azabenzo(a)pyrene). The limit of detection of this method ranges from 0.1 to 0.4 ng for benzacridines, dibenzacridines, and their methyl derivatives. The results of a collaborative study, stimulated by IUPAC, are reported: Coefficients of variation for the various azaarenes were 4.0-13.6% for the check analysis and 10.4-25.4% for a spiked ham sample. Consequently, IUPAC suggests this procedure as a recommended method.

scholarly journals Electrochemical detection of different p53 conformations by using nanostructured surfaces

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sarah Tonello ◽  
Francesca Stradolini ◽  
Giulia Abate ◽  
Daniela Uberti ◽  
Mauro Serpelloni ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Limit Of Detection ◽  
Direct Electrochemistry ◽  
Protein Quantification ◽  
Label Free ◽  
Limited Information ◽  
Clinical Practices ◽  
Nanostructured Surfaces ◽  
Integrated Devices ◽  
Biochemical Assays

AbstractProtein electrochemistry represents a powerful technique for investigating the function and structure of proteins. Currently available biochemical assays provide limited information related to the conformational state of proteins and high costs. This work provides novel insights into the electrochemical investigation of the metalloprotein p53 and its redox products using label-free direct electrochemistry and label-based antibody-specific approaches. First, the redox activities of different p53 redox products were qualitatively investigated on carbon-based electrodes. Then, focusing on the open p53 isoform (denatured p53), a quantitative analysis was performed, comparing the performances of different bulk and nanostructured materials (carbon and platinum). Overall, four different p53 products could be successfully discriminated, from wild type to denatured. Label-free analysis suggested a single electron exchange with electron transfer rate constants on the order of 1 s−1. Label-based analysis showed decreasing affinity of pAb240 towards denatured, oxidized and nitrated p53. Furthermore, platinum nanostructured electrodes showed the highest enhancement of the limit of detection in the quantitative analysis (100 ng/ml). Overall, the obtained results represent a first step towards the implementation of highly requested complex integrated devices for clinical practices, with the aim to go beyond simple protein quantification.

scholarly journals A simple method for the analysis of urinary sucralose for use in tests of intestinal permeability

2005 ◽  
Vol 42 (3) ◽  
pp. 224-226 ◽  
Author(s):  
A D G Anderson ◽  
P Poon ◽  
G M Greenway ◽  
J MacFie
Keyword(s):  
Refractive Index ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Simple Method ◽  
Standard Curve ◽  
Additional Information ◽  
Accuracy And Precision ◽  
Analytical Recovery ◽  
Peak Areas ◽  
Syringe Filter

Background: Sucralose is a unique disaccharide probe which is stable in the colon and can be used to assess permeability over the whole gut. Additional information can be gained when sucralose is administered in combination with lactulose and a monosaccharide such as L-rhamnose in the form of a 'triple sugar test.' We describe a simple assay for urinary sucralose by HPLC with refractive index detection (HPLC-RI). Methods: Phenyl-β-D-glucopyranoside (internal standard) was added to 10 mL of urine, which was then passed through a 0.45 μm syringe filter. Elution was with 30% methanol (1 mL/min) on a reverse-phase C18 column. Detection was by refractive index, and integration based upon peak areas. Sixty standards of sucralose in human urine were analysed in order to quantify analytical variation. Results: The standard curve for urinary sucralose was linear from 25 to 500 mg/L ( r>0.99). The limit of detection was 11 mg/L. Analytical recovery of sucralose at concentrations of 25, 50 and 100 mg/L was 101.5% (CV 7.59%), 102.9% (CV 5.82%) and 105.0% (CV 4.26%), respectively Conclusions: The technique described represents a simple assay for urinary sucralose which performed with acceptable accuracy and precision and should facilitate the use of the triple sugar test in clinical research.

scholarly journals Rapid and sensitive detection of uranyl ion with citrate-stabilized silver nanoparticles by the surface-enhanced Raman scattering technique

2018 ◽  
Vol 5 (11) ◽  
pp. 181099 ◽  
Author(s):  
Jiaolai Jiang ◽  
Shaofei Wang ◽  
Hui Deng ◽  
Haoxi Wu ◽  
Jun Chen ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Quantitative Analysis ◽  
Limit Of Detection ◽  
Nuclear Industry ◽  
Internal Reference ◽  
Surface Enhanced ◽  
Scattering Technique ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Relationship Of

Uranium contamination poses a huge threat to human health due to its widespread use in the nuclear industry and weapons. We proposed a simple and convenient wet-state SERS method for uranyl detection based on the citrate-stabilized silver nanoparticles. The effect of citrate on the detection performance was also discussed. By using the citrate as an internal reference to normalize the peak of uranyl, a quantitative analysis was achieved and a good linear relationship of uranyl concentration from 0.2 to 5 µM with the limit of detection of 60 nM was obtained. With its simplicity, convenience and cost-effectiveness, this method has great potential for the detection of other molecules also.

Improved liquid-chromatographic method for determination of serum cortisol.

1979 ◽  
Vol 25 (7) ◽  
pp. 1293-1296 ◽  
Author(s):  
P M Kabra ◽  
L L Tsai ◽  
L J Marton
Keyword(s):  
Limit Of Detection ◽  
Internal Standard ◽  
Serum Cortisol ◽  
Peak Height ◽  
Reversed Phase ◽  
Column Temperature ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract We describe a specific and precise method for measuring concentrations of cortisol in serum or plasma by liquid chromatography. Cortisol, together with an internal standard, equilenin, is extracted from 1 mL of serum or plasma and analyzed isocratically on a reversed-phase column with a mobile phase of acetonitrile/phosphate buffer (30/70, by vol.), at a flow rate of 2.0 mL/min. The eluted cortisol is detected by its absorption at 254 nm and quantitated by peak height measurements. Each analysis requires no longer than 15 min at the optimum column temperature of 50 degrees C. The lower limit of detection for cortisol is about 2 ng/sample for a standard solution; sensitivity is routinely 5 micrograms/L of serum. Analytical recoveries exceeded 95%, with good day-to-day precision (coefficients of variation between 4 and 7%). Of more than 50 drugs and steroids tested for possible interference, only the steroids cortisone, prednisone, and prednisolone may interfere with the analysis of cortisol.

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