RP-HPLC study of redox equilibria in vanadium-PAR binary and ternary systems: Direct determination of vanadium in steel

A method for the determination of individual components of complex mixtures is presented. The technique used is based on ir-absorbance measurements for stearic acid at 1700 and at 935 cm−1 when the concentration range exceeds 0.50% wt/vol; for isopropenyl stearate at 1145 and at 865 cm−1; for stearic anhydride at 1030 cm−1 and mixed stearic-acetic anhydride at 1000 cm−1. The baseline method was used in all absorbance measurements. Absorbance-concentration relationships obeyed Beer's law from 0 to 2.0% wt/vol for most compounds; the exception being stearic acid (at 1700 cm−1), where linearity was limited to a maximum 0.50% wt/vol. Due to spectral interference between the two anhydrides at low concentration ratios, an empirical percent transmission ratio method was used to estimate the relative concentration of each. Binary and ternary systems were studied and the standard deviations of the differences between theoretical and calculated values indicate that this method is reliable.

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Spectrophotometric study of reaction of sodium 6-hydroxy-5-dibenzo(a,j)phenoxazone-11,13-disulfonate with aluminium ions in the presence of cationoid tensides

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19801227 ◽

1980 ◽

Vol 45 (4) ◽

pp. 1227-1235

Author(s):

Nguyen Truong Son ◽

Jan Lasovský ◽

Eduard Ružička

Keyword(s):

Acidic Medium ◽

Equilibrium Constants ◽

Ternary Systems ◽

Photometric Determination ◽

Spectrophotometric Study ◽

Ternary Complexes ◽

Medium Ph ◽

Binary And Ternary Systems

In weakly acidic medium, pH 3.5-6.5, the title dye forms with aluminium ions a complex with the Al : L ratio 1 : 1. In the presence of cetylpyridinium or carbethoxypentadecyltrimethylammonium, ternary complexes AlL3Sr (r = 6 or 9, respectively) are formed. The equilibrium constants of the complexing equilibria in the binary and ternary systems concerned were calculated, and a method of photometric determination of aluminium has been suggested.

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DIRECT DETERMINATION OF ALUMINUM IN DRINKING AND NATURAL WATERS AS 8-HYDROXYQUINOLINE CHELATE BY RP-HPLC

Journal of Liquid Chromatography &amp Related Technologies ◽

10.1081/jlc-100001483 ◽

2001 ◽

Vol 24 (2) ◽

pp. 215-228 ◽

Cited By ~ 7

Author(s):

Hong-Zhen Lian ◽

Shu-Ping Bi ◽

Yi-Jun Chen ◽

Lei-Mei Dai ◽

Mi Cao ◽

...

Keyword(s):

Natural Waters ◽

Direct Determination ◽

Rp Hplc

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Convex hull method for the determination of vapour-liquid equilibria (VLE) phase diagrams for binary and ternary systems

Fluid Phase Equilibria ◽

10.1016/j.fluid.2016.09.024 ◽

2017 ◽

Vol 431 ◽

pp. 34-47 ◽

Cited By ~ 3

Author(s):

Amieibibama Joseph ◽

Christine M. Sands ◽

Peter D. Hicks ◽

Howard W. Chandler

Keyword(s):

Convex Hull ◽

Phase Diagrams ◽

Ternary Systems ◽

Binary And Ternary Systems ◽

Convex Hull Method

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Thermodynamic calculations in alloys Ti-Al, Ti-Fe, Al-Fe and Ti-Al-Fe

Journal of Mining and Metallurgy Section B Metallurgy ◽

10.2298/jmmb0801049k ◽

2008 ◽

Vol 44 (1) ◽

pp. 49-61 ◽

Cited By ~ 22

Author(s):

Ana Kostov ◽

B. Friedrich ◽

D. Zivkovic

Keyword(s):

Phase Diagrams ◽

Ternary Alloy ◽

Ternary Systems ◽

Thermodynamic Calculations ◽

Calculated Phase ◽

Gibbs Energies ◽

Different Temperatures ◽

Binary And Ternary Systems ◽

Thermodynamic Determination

Thermodynamic calculations of three binary Ti-based alloys: Ti-Al, Ti-Fe, and Al-Fe, as well as ternary alloy Ti-Al-Fe, is shown in this paper. Thermodynamic calculations involved thermodynamic determination of activities, coefficient of activities, partial and integral values for enthalpies and Gibbs energies of mixing and excess energies at different temperatures: 1873K, 2000K and 2073K, as well as calculated phase diagrams for the investigated binary and ternary systems. The FactSage is used for all thermodynamic calculations.

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Spectrofluorimetric determination of quercetin in pharmaceutical dosage forms

Macedonian Journal of Chemistry and Chemical Engineering ◽

10.20450/mjcce.2014.496 ◽

2014 ◽

Vol 33 (2) ◽

pp. 209 ◽

Cited By ~ 5

Author(s):

Leposava Pavun ◽

Predrag Đurđević ◽

Milena Jelikić-Stankov ◽

Daniela Đikanović ◽

Andrija Ćirić ◽

...

Keyword(s):

Direct Determination ◽

Dosage Forms ◽

Font Size ◽

Pharmaceutical Dosage Forms ◽

Strong Emission ◽

Rp Hplc ◽

Spectrofluorimetric Method ◽

Spectrofluorimetric Determination ◽

Good Agreement

The simple, accurate and precise method based on fluorescence properties of aluminium (III)–quercetin complex, for the determination of quercetin has been developed and validated. The complex has strong emission at pH 3.30, lem = 480 nm, with lex = 420 nm. Linearity range of quercetin determination was 1.5 - 60.5 ng mL-1 with LOD 0.09 ng mL-1 and LOQ 0.27 ng mL-1. Recovery values in the range of 99.9 – 100.2 % indicate a good accuracy of the method. The established method was applied for the determination of quercetin in capsules, with Recovery value 98.3 %, standard deviation 0.22 % and coefficient of variation 0.09 %. The reliability of the method was checked by RP-HPLC/UV method for capsules with direct determination of quercetin after separation. The good agreement between two methods indicates the applicability usability of the proposed spectroflurometric method for quercetin determination in pharmaceutical dosage forms, with high reproducibility, and enables direct and simple determination without its prior extraction from samples.The proposed spectrofluorimetric method has much better sensitivity and about 1000 times lower LOD and LOQ values compared to data reported in literature.

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Optimization and Validation of an RP-HPLC Method for Direct Determination of Metformin Hydrochloride in Human Urine and in a Dosage Form

Journal of AOAC International ◽

10.1093/jaoac/93.6.1821 ◽

2010 ◽

Vol 93 (6) ◽

pp. 1821-1828 ◽

Cited By ~ 1

Author(s):

Alaa El-Gindy ◽

Mohammed Wafaa Nassar ◽

Nasr Mohammed El-Abasawy ◽

Khalid Abdel-Salam Attia ◽

Maisra Al-Shabrawi

Keyword(s):

Human Urine ◽

Direct Determination ◽

Hplc Method ◽

Metformin Hydrochloride ◽

Dihydrogen Phosphate ◽

Sodium Dihydrogen Phosphate ◽

Linear Calibration ◽

Rp Hplc ◽

Acid Sodium Salt

Abstract A simple, selective, sensitive, accurate, and precise method was developed for determination of metformin hydrochloride (MF) in human urine using RP-HPLC. The method depends upon using an octylsilyl (C8) 5 m particle size column at ambient temperature with mobile phase consisting of 33 mM sodium dihydrogen phosphate containing 6.38 mM hexanesulfonic acid sodium salt and adjusted to apparent pH 3.0 with phosphoric acidacetonitrile (93 7, v/v) at a flow rate of 1.5 mL/min. Quantitation was achieved with UV detection at 231 nm based on peak area with a linear calibration curve over the concentration range of 0.0150 g/mL. The proposed method was applied to the determination of the urinary excretion pattern of MF (the cumulative amounts excreted were calculated without pretreatment of the urine sample) and for determination of the dissolution pattern of MF tablets. The proposed method was completely validated according to the U.S. Food and Drug Administration guidelines.

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