DETERMINATION OF URANIUM IN FLOTATION CONCENTRATES AND IN LEACH LIQUORS BY X-RAY FLUORESCENCE

1959 ◽  
Vol 37 (1) ◽  
pp. 20-28 ◽  
Author(s):  
G. L. Smithson ◽  
R. L. Eager ◽  
A. B. VanCleave
Keyword(s):  
Direct Measurement ◽  
Pilot Plant ◽  
Internal Standard ◽  
Liquid Extraction ◽  
X Ray ◽  
Liquid Liquid Extraction ◽  
Northern Saskatchewan ◽  
Plant Operations ◽  
Time Required

X-Ray fluorescence has been applied to the analysis of flotation concentrates obtained from pegmatitic uranium ores occurring in Northern Saskatchewan. Approximate uranium analyses can be obtained by direct measurement on flotation concentrates but more accurate results are obtained by using an internal standard such as strontium or yttrium. The time required for an analysis, as compared to that of conventional chemical or fluorimetric methods, is considerably reduced and flotation pilot plant operations can therefore be more effectively controlled. The method has been extended to include the analysis of sulphate leach liquors obtained from the leaching of pegmatitic ores and their flotation concentrates. Organic phases obtained in liquid – liquid extraction studies can also be rapidly analyzed for uranium by X-ray fluorescence.

Determination of Uranium in Flotation Concentrates and in Leach Liquors by X-Ray Fluorescence

1958 ◽  
Vol 2 ◽  
pp. 175-191
Author(s):  
G. L. Smithson ◽  
R. L. Eager ◽  
A. B. Van Cleave
Keyword(s):  
Pilot Plant ◽  
Internal Standard ◽  
X Ray ◽  
Additional Information ◽  
Fluorescence Methods ◽  
Northern Saskatchewan ◽  
Plant Operations ◽  
Time Required

AbstractX-ray fluorescence has been applied to the analysis of flotation concentrates obtained from pegmatitic uranium ores occurring in Northern Saskatchewan. It has been found necessary to use an internal standard such as strontium or yttrium. The time required for an analysis, as compared to that of conventional chemical or U.V. fluorescence methods, is considerably reduced and flotation pilot plant operations can therefore be more effectively controlled. The method has been extended to include the analysis of sulphate liquors obtained from the leaching of pegmatitic ores and their flotation concentrates. The amount of iron present in the samples is also determined by reference to the internal standard used for the uranium. This additional information is useful in assessing the efficiency of various flotation and leaching techniques.

scholarly journals DEVELOPMENT AND VALIDATION OF RP-HPLC METHOD FOR THE DETERMINATION OF ALVIMOPAN IN RAT PLASMA

2018 ◽  
Vol 10 (10) ◽  
pp. 124
Author(s):  
Devi Ramesh ◽  
Mohammad Habibuddin
Keyword(s):  
Method Development ◽  
Internal Standard ◽  
The United States ◽  
Hplc Method ◽  
Liquid Extraction ◽  
Pharmacokinetic Parameters ◽  
Dihydrogen Phosphate ◽  
Liquid Liquid Extraction ◽  
Validation Parameters

Objective: The present investigation demonstrates a simple, sensitive and accurate high pressure liquid chromatographic (HPLC) method for the determination of alvimopan (AMP) in rat plasma.Methods: The chromatographic separation was achieved within 10 min by using acetonitrile: potassium dihydrogen phosphate buffer pH 3.0 adjusted with orthophosphoric acid (50:50) as mobile phase on Altima Grace Smart C-18 column (5μ; 250 × 4.6 mm) at a flow rate of 1.0 ml/min with injection volume 50 µl. The drug was extracted from plasma by liquid-liquid extraction using a mixture of methanol: acetonitrile (50:50) as a solvent. The retention times of drug and internal standard were found to be 5.17 and 6.74 min, respectively. This method was validated as per the United States Food and Drug Administration (US-FDA) guidelines.Results: The results of the validation parameters were found to be within the acceptance limits. The method was linear in the concentration range from 5-1000 ng/ml (r2= 0.9998), and the extraction recovery was found to be 78.71±3.86% for AMP. The lower limit of quantification was found to be 5ng/ml, and the stability of recovered samples at different conditions was found to be more than 95%.Conclusion: The developed method possess good selectivity, specificity, there was no interference found in the plasma blanks at retention times of AMP and Internal Standard (IS). We found a good correlation between the peak area and concentration of the drug under prescribed conditions. Furthermore, the method can also be used to estimate the pharmacokinetic parameters of AMP.Keywords: Alvimopan, Liquid-liquid extraction, Method development, Matrix effect, Plasma, Recovery, Stability, Validation

A novel liquid-liquid extraction for the determination of naphthalene by GC-MS with deuterated anthracene as internal standard

2017 ◽  
Vol 189 (10) ◽  
Author(s):  
Sezin Erarpat ◽  
Gözde Özzeybek ◽  
Dotse Selali Chormey ◽  
Fatih Erulaş ◽  
Fatma Turak ◽  
...  
Keyword(s):  
Internal Standard ◽  
Liquid Extraction ◽  
Liquid Liquid Extraction

A Novel Liquid–Liquid Extraction for the Determination of Nicotine in Tap Water, Wastewater, and Saliva at Trace Levels by GC-MS

2016 ◽  
Vol 99 (3) ◽  
pp. 806-812 ◽  
Author(s):  
Joanna Sonia Dobrowska ◽  
Sezin Erarpat ◽  
Dotse Selali Chormey ◽  
Krystyna Pyrzyńska ◽  
Sezgin Bakirdere
Keyword(s):  
Analytical Method ◽  
Tap Water ◽  
Internal Standard ◽  
Liquid Extraction ◽  
Calibration Plot ◽  
Optimum Conditions ◽  
Extraction Solvent ◽  
Liquid Liquid Extraction ◽  
Extraction Period

Abstract Determination of nicotine at trace levels in different matrixes is crucial because of nicotine's strongly addictive property. In this study, a simple and fast analytical method was developed using liquid–liquid extraction with GC-MS. Chloroform was used as an extraction solvent. Different parameters for extraction, such as pH of the solution, types and volumes of extraction and supporter solvents for dispersion, extraction period, and salt type and its amount, were optimized. To improve the precision, naphthalene was used as an internal standard. The calibration plot of nicotine was linear from 0.010 to 2.0 mg/L with a correlation coefficient 0.9996. The LOD and LOQ for nicotine after extraction were 2.6 and 8.8 ng/mL, respectively. Under the optimum conditions, tap water, wastewater, and saliva samples were analyzed for their nicotine content. The spiking experiments yielded satisfactory recoveries of 97.6 ± 3.5, 96.8 ± 1.1, and 85.1 ± 1.3% for tap water, wastewater, and saliva samples, respectively.

scholarly journals Development and Validation of UPLC-MS/MS Method for the Determination of Aripiprazole in Rat Plasma Using Liquid-Liquid Extraction: Pharmacokinetic and Bioequivalence Application

2020 ◽  
Vol 32 (10) ◽  
pp. 2671-2676
Author(s):  
Ashish Raghuvanshi ◽  
Urooj A. Khan ◽  
Uzma Parveen ◽  
Anshul Gupta ◽  
Gaurav K. Jain
Keyword(s):  
Internal Standard ◽  
Rat Plasma ◽  
Liquid Extraction ◽  
Single Step ◽  
Liquid Liquid Extraction ◽  
Validation Parameters ◽  
Tandem Mass Spectrometric ◽  
Liquid Chromatographic

A selective, simple, sensitive and rapid ultra-performance liquid chromatographic tandem mass spectrometric (UPLC-MS/MS) method for the detection of aripiprazole in rat plasma has been developed and validated using aripiprazole-D8 as internal standard (IS). A simple single step sample preparation process was accomplished by liquid-liquid extraction (LLE). The post-treatment samples were chromato-graphed and analyzed on a UPLC bridged ethyl hybrid (BEH) C-18 column using mobile phase composition of acetonitrile: 0.1% formic acid in water::70:30 (v/v). Aripiprazole was analyzed by MS detector in positive electrospray ionization mode (ESI). Multiple reactions monitoring (MRM) was employed to observed the transition for aripiprazole (m/z 448.35→285.09) and aripiprazole-D8 (m/z 456.2→293.2). The developed method was validated and found linear in the working range of 2-1025 ng/mL with correlation coefficient, r2 = 0.99951 and quantification limit of 2.02 ng/mL. All validation parameters were in accordance with the ICH guidelines and met the acceptance criteria. The method was found to be accurate (recovery, 97.07 to 103.64%, precise (% CV, 2.68 to 7.70%), rapid (run time 4 min) and specific. The validated method was successfully used for the determination of plasma concentration of aripiprazole after single oral administration in rats and hence could be useful for in vivo pharmacokinetic study and bioequivalence testing of aripiprazole formulations.

Determination of the antidepressant fluoxetine and its metabolite norfluoxetine in serum by reversed-phase HPLC with ultraviolet detection.

1988 ◽  
Vol 34 (9) ◽  
pp. 1875-1878 ◽  
Author(s):  
P J Orsulak ◽  
J T Kenney ◽  
J R Debus ◽  
G Crowley ◽  
P D Wittman
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Reversed Phase ◽  
Liquid Extraction ◽  
Reversed Phase Hplc ◽  
Reduced Haloperidol ◽  
Ultraviolet Detection ◽  
Standard Curve ◽  
Liquid Liquid Extraction

Abstract A procedure has been developed for measuring fluoxetine and its desmethyl metabolite, norfluoxetine, in serum by reversed-phase high-performance liquid chromatography (HPLC), with ultraviolet detection at 226 nm. Fluoxetine and norfluoxetine are isolated from serum by liquid-liquid extraction. They are then separated by HPLC and quantified, with reduced haloperidol as the internal standard. Fluoxetine, norfluoxetine, and the reduced haloperidol are separated from all interfering peaks in about 15 min. The standard curve is linear (r = 1.000) for both fluoxetine and norfluoxetine concentrations over the range of 25 to 800 micrograms/L. Between-run CVs for 60 and 200 micrograms/L controls (n = 8) were 6.8 and 4.1% for fluoxetine, and 8.8 and 6.2% for norfluoxetine, respectively. In a study of 24 patients with depression who were being treated with 20-60 mg of fluoxetine per day, fluoxetine and norfluoxetine concentrations in serum, measured during the last three weeks of treatment, were 47-469 micrograms/L and 52-446 micrograms/L, respectively.

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