Simultaneous analysis of three catecholamines by a kinetic procedure: comparison of prediction performance of several different multivariate calibrations

2011 ◽  
Vol 65 (6) ◽  
Author(s):  
Yongnian Ni ◽  
Yao Gu ◽  
Serge Kokot
Keyword(s):  
High Performance ◽  
Multivariate Calibration ◽  
Kinetic Method ◽  
Simultaneous Analysis ◽  
Rabbit Serum ◽  
Serum Samples ◽  
Consecutive Reaction ◽  
Calibration Models ◽  
Spectrophotometric Data

AbstractA rapid kinetic method for the simultaneous determination of levodopa, dopamine, and dobutamine was examined and developed. It was based on a consecutive reaction of a reduction of Cu(II) to Cu(I) by catecholamines, followed by the complexation of Cu(I) with neocuproine to form a yellow product in an acetic acid-acetate buffer. Spectrophotometric data were recorded at 453 nm (wavelength at the yellow complex absorption maximum) for 300 s. Linear calibrations were obtained in the concentration ranges of (0.08–1.44) × 10−5 mol L−1, (0.08–1.44) × 10−5 mol L−1, and (0.16–1.44) × 10−5 mol L−1 for levodopa, dopamine, and dobutamine, respectively. A variety of multivariate calibration models was developed for simultaneous analysis of the three analytes; while most models produced satisfactory prediction results for synthetic samples, the hybrid linear analysis method was arguably the best-performing (relative prediction error, RPET = 6.6 %). The proposed method was applied to an analysis of spiked rabbit serum samples and the results showed good agreement with the high performance liquid chromatography measurements.

The Dtermination of Paracetamol by HPLC Validation of the Method and Application on Serum Samples

2018 ◽  
Vol 69 (3) ◽  
pp. 627-631 ◽  
Author(s):  
Viorica Ohriac (Popa) ◽  
Diana Cimpoesu ◽  
Adrian Florin Spac ◽  
Paul Nedelea ◽  
Voichita Lazureanu ◽  
...  
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Hplc Analysis ◽  
Emotional Experience ◽  
Optimum Conditions ◽  
Serum Samples ◽  
Liquid Chromatograph ◽  
Mobile Phase Flow Rate ◽  
Quantification Limit

Pain is defined as a disagreeable sensory and emotional experience related to a tissue or potential lesion. Paracetamol (Acetaminophen) is the most used non-morphine analgesic. For the determination of paracetamol we developed and validated the high performance liquid chromatography (HPLC) analysis using a Dionex Ultimate 3000 liquid chromatograph equipped with a multidimensional detector. After determining the optimum conditions of analysis (80/20 water / acetonitrile mobile phase, flow rate 1.0 mL / min, detection wavelength 245 nm) we validated the method following the following parameters: linearity of response function, linearity of results, limit (LD = 0.66 mg / mL) and quantification limit (LQ = 2.00 mg / mL), and precision. The method of determining paracetamol by HPLC was applied to 30 samples of serum collected from patients who had pain and were treated with paracetamol.

scholarly journals Determination of (–)-Quinine and (+)-Quinidine by Liquid Chromatography with Diode-Laser Polarimetric Detection

1999 ◽  
Vol 82 (6) ◽  
pp. 1308-1315 ◽  
Author(s):  
Francisco García Sánchez ◽  
Aurora Navas Díaz ◽  
Angeles García Pareja ◽  
Germán Cabrera Montiel
Keyword(s):  
Liquid Chromatography ◽  
Diode Laser ◽  
Mobile Phase ◽  
High Performance ◽  
Dynamic Range ◽  
Reversed Phase ◽  
Rabbit Serum ◽  
In Series ◽  
Phase Column

Abstract High-performance liquid chromatography using a combination of photometric, fluorimetric, and diode-laser polarimetric detectors in series for the determination of (+)-quinidine and (–)-quinine was investigated. An RP-8 reversed-phase column and methanol-water (80 + 20, v/v) with 0.2% triethylamine as mobile phase at a flow rate of 1 mL/min were used. A dynamic range of 0-200 μg for (+)-quinidine and (+)-quinine was established, with detection limits of 17.0 and 16.7 μg, respectively. An application of this method in spiked rabbit serum was developed.

scholarly journals Different spectrophotometric and TLC-densitometric methods for determination of olmesartan medoxomil and hydrochlorothiazide and their degradation products

2018 ◽  
Vol 9 (4) ◽  
pp. 400-407 ◽  
Author(s):  
Selvia Maged Adly ◽  
Maha Mohamed Abdelrahman ◽  
Nada Sayed Abdelwahab ◽  
Nourudin Wageh Ali
Keyword(s):  
Multivariate Calibration ◽  
Degradation Products ◽  
External Validation ◽  
Olmesartan Medoxomil ◽  
Partial Least Square ◽  
Least Square ◽  
Pharmaceutical Dosage Form ◽  
Calibration Models ◽  
Significant Difference

In this work, multivariate calibration models and TLC-densitometric methods have been developed and validated for quantitative determination of olmesartan medoxomil (OLM) and hydrochlorothiazide (HCZ) in presence of their degradation products, olmesartan (OL) and salamide (SAL), respectively. In the first method, multivariate calibration models including principal component regression (PCR) and partial least square (PLS) were applied. The wavelength range 210-343 nm was used and data was auto-scaled and mean centered as pre-processing steps for PCR and PLS models, respectively. These models were tested by application to external validation set with mean percentage recoveries 99.78, 100.01, 100.41 and 100.46% for OLM, HCZ, OL and SAL, respectively, for PLS model and also, 100.22, 100.40, 102.25 and 100.13% for them, respectively, for PCR model. The second method is TLC-densitometry at which the chromatographic separation was carried out using silica gel 60F254 TLC plates and the developing system consisted of a mixture of ethyl acetate:chloroform:methanol: formic acid:tri-ethylamine (60:40:4:4:1, by volume) with UV-scanning at 254 nm. The developed methods were successfully applied for determination of OLM and HCZ in their pharmaceutical dosage form. Also, statistical comparison was made between the developed methods and the reported method using student’s-t test and F-test and results showed that there was no significant difference between them concerning both accuracy and precision.

PSV-4 Determination of Deoxynivalenol (DON) Content in Biological Samples as an Indicator of DON Intake in Grower-finisher Pigs

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 206-207
Author(s):  
Michael O Wellington ◽  
Michael A Bosompem ◽  
Veronika Nagl ◽  
Daniel A Columbus
Keyword(s):  
Mass Spectrometry ◽  
Biological Samples ◽  
High Performance ◽  
Tandem Mass ◽  
Serum Samples ◽  
Blood Samples ◽  
Swine Diets ◽  
Direct Quantification ◽  
Serum And Urine

Abstract Due to difficulties in obtaining consistent and/or reliable measures of deoxynivalenol (DON) in complete swine diets, we investigated whether measuring DON in biological samples could be used as an indicator of DON ingestion in pigs. In this study, graded levels of DON (1, 3, or 5 ppm) were fed to grower-finisher pigs for a period of 77-d. On d 35 and 77 of the study, urine samples were quantitatively collected over a 24-h period and blood samples were collected between 3 – 4 h after the morning meal on each of those days for serum DON analysis. For direct quantification of DON in urine, high-performance liquid chromatography with tandem mass spectrometry was performed. For serum samples, indirect quantification of DON was performed via enzymatic hydrolysis. We observed that DON content in urine increased linearly as intake of DON increased (Fig.1A; P < 0.05). Analysis of DON in serum follow a similar trend, where serum DON content was increased as DON intake increased (Fig.1B; P < 0.05). An average of 30% of DON ingested was recovered as DON in urine over a 24-h period. In summary, there was a linear relationship between DON intake and DON content in both urine and blood serum, therefore, analyzing DON concentration in serum and urine could be used as a tool to estimate for DON exposure in pigs under controlled conditions.

Kinetic and spectrophotometric studies of binding of iron(III) by glutathione

1976 ◽  
Vol 54 (20) ◽  
pp. 3192-3199 ◽  
Author(s):  
Tahir R. Khan ◽  
Cooper H. Langford
Keyword(s):  
Complex Formation ◽  
Kinetic Method ◽  
Binding Constants ◽  
Chelating Agent ◽  
Formation Reaction ◽  
Spectrophotometric Data ◽  
Natural Water Chemistry ◽  
Kinetics Of ◽  
Sulfur Containing

In this report, determination of unbound aquo iron species is accomplished by a kinetic method involving reaction with sulfosalicylic acid (SSA) on a time scale which is very short with respect to reaction of SSA with the glutathione complexes of iron. The data are used to calculate conditional binding constants for Fe(III) to glutathione. Binding constants in 0.1 M ionic strength media were obtained between pH 1 and 2.4 by the kinetic method, and near pH = 3 by spectrophotometry and by examination of the ratio of rate of complex formation and dissociation. The conditional binding 'constant' between pH 1 and 3 is represented as pK = −1.96 – 0.50pH. This is consistent with the importance of reactions involving only very limited proton release. Spectrophotometric data show that the —OH group on Fe(OH)2+ is lost on glutathione complexing. Kinetics of the complex formation reaction between aquo iron(III) species and glutathione are slower than rates of reaction of iron(III) with simple ligands.The glutathione system is regarded as a model system important to natural water chemistry because it is a widely distributed biological sulfur-containing chelating agent.

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