Determination of remifentanil in human blood by liquid-liquid extraction and capillary GC-HRMS-SIM using a deuterated internal standard

1994 ◽  
Vol 12 (2) ◽  
pp. 195-203 ◽  
Author(s):  
C.M. Grosse ◽  
I.M. Davis ◽  
R.F. Arrendale ◽  
J. Jersey ◽  
J. Amin
Keyword(s):  
Human Blood ◽  
Internal Standard ◽  
Liquid Extraction ◽  
Capillary Gc ◽  
Liquid Liquid Extraction ◽  
Deuterated Internal Standard

scholarly journals New Method for Determination of Ten Pesticides in Human Blood

2001 ◽  
Vol 84 (2) ◽  
pp. 342-349 ◽  
Author(s):  
Rosario GarcÍa-Repetto ◽  
M Paz Giménez ◽  
Manuel Repetto
Keyword(s):  
Human Blood ◽  
Solid Phase ◽  
Internal Standard ◽  
Current Method ◽  
Liquid Extraction ◽  
Internal Standards ◽  
Liquid Liquid Extraction ◽  
Nitrogen Phosphorus ◽  
Impact Mode

Abstract An analytical method was developed for precise identification and quantitation of 10 pesticides in human blood. The pesticides studied, which have appeared frequently in actual cases, were endosulfan, lindane, parathion, ethyl-azinphos, diazinon, malathion, alachlor, tetradifon, fenthion and dicofol (o-p′ and p-p′ isomers). The current method replaces an earlier method which involved liquid–liquid extraction with a mixture of n-hexane–benzene (1 + 1). The extraction is performed by solid-phase extraction, with C18 cartridges and 2 internal standards, perthane and triphenylphosphate. Eluates were analyzed by gas chromatography (GC) with nitrogen–phosphorus and electrochemical detectors. Results were confirmed by GC–mass spectrometry in the electron impact mode. Blood blank samples spiked with 2 standard mixtures and an internal standard were used for quantitation. Mean recoveries ranged from 71.83 to 97.10%. Detection and quantitation limits are reported for each pesticide. Examples are provided to show the application of the present method to actual samples.

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.

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.

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