Determination of valproic acid and 3-heptanone in plasma using air-assisted liquid-liquid microextraction with the assistance of vortex: Application in the real samples

Introduction: Valproic acid (VPA) is an antiepileptic drug used to treat epilepsy and bipolar disorder. Adverse effects of VPA were studied in many reports, however, a dose-response relationship between VPA and its metabolites in epilepsy patients are extremely limited. In this paper, a high efficient method was developed for the preconcentration and determination of VPA and its main metabolite in plasma. Methods: For the extraction and preconcentration of the selected analytes, a volume of an extractant was placed at the bottom of the microtube containing pretreated plasma. The mixture was repeatedly withdrawn from the microtube and pushed-out into it using a 1.0-mL glass syringe and resulted in a cloudy mixture. For further turbidity, the mixture was shaken on a vortex agitator. This procedure was used to analyze the plasma samples of patients with epilepsy (n = 70). Results: The results revealed that in most patients with a low level of VPA relative to its expected level, 3-heptanone concentrations were high. The limits of quantification of 3-heptanone and VPA were 0.04 mg L–1 and 0.2 mg L–1, respectively. A suitable precision at a concentration of 2 mg L-1 for each analyte was obtained (relative standard deviation ≤ 9%). Conclusion: The obtained results indicated that this procedure is easy, sensitive, and reliable, and can be used for the analysis of the selected analytes in the plasma samples of patients with epilepsy.

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Development of an HPLC-UV Method for Quantification of Stattic

Current Pharmaceutical Analysis ◽

10.2174/1573412914666180523092957 ◽

2019 ◽

Vol 15 (6) ◽

pp. 568-573

Author(s):

Soheil Sedaghat ◽

Ommoleila Molavi ◽

Akram Faridi ◽

Ali Shayanfar ◽

Mohammad Reza Rashidi

Keyword(s):

High Performance ◽

Accurate Method ◽

Plasma Samples ◽

Promising Target ◽

Relative Standard ◽

Dimerization Inhibitor ◽

Oncogenic Protein ◽

First Time ◽

Transcription 3

Background: Signal transducer and activator of transcription 3 (STAT3), an oncogenic protein found constitutively active in many types of human malignancies, is considered to be a promising target for cancer therapy. Objective: In this study for the first time, a simple and accurate method has been developed for the determination of a STAT3 dimerization inhibitor called stattic in aqueous and plasma samples. Methods: A reverse-phase high-performance liquid chromatography (RP-HPLC) composed of C18 column as stationary phase, and the mixture of acetonitrile (60%) and water (40%) as mobile phase with a UV detection at 215 nm were applied for quantification of stattic. The developed method was validated by Food and Drug Administration (FDA) guideline. Results: The method provided a linear range between 1-40 and 2.5-40 µg mL-1 for aqueous and plasma samples, respectively, with a correlation coefficient of 0.999. The accuracy (as recovery) of the developed method was found to be between 95-105% for aqueous medium and 85-115% for plasma samples. The precision (as relative standard deviation) for aqueous and plasma samples was less than 6% and 15%, respectively. The sensitivity of the developed method based on FDA guideline was 1 µg mL-1 for aqueous and 2.5 µg mL-1 for plasma samples. Conclusion: These results show that the established method is a fast and accurate quantification for stattic in aqueous and plasma samples.

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Simultaneous determination of valproic acid and 2-propyl-4-pentenoic acid for the prediction of clinical adverse effects in Chinese patients with epilepsy

Seizure ◽

10.1016/j.seizure.2011.10.002 ◽

2012 ◽

Vol 21 (2) ◽

pp. 110-117 ◽

Cited By ~ 19

Author(s):

Zhuo-jia Chen ◽

Xue-ding Wang ◽

Hong-sheng Wang ◽

Shu-da Chen ◽

Lie-min Zhou ◽

...

Keyword(s):

Valproic Acid ◽

Adverse Effects ◽

Simultaneous Determination ◽

Chinese Patients ◽

Patients With Epilepsy

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Simultaneous Determination of Four Plant Hormones in Soil by Ultrasound-Assisted Ionic Liquid Based Dispersive Liquid-Liquid Microextraction

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.675-677.181 ◽

2014 ◽

Vol 675-677 ◽

pp. 181-184 ◽

Cited By ~ 4

Author(s):

Gui Qi Huang ◽

She Ying Dong ◽

Zhen Yang ◽

Ting Lin Huang

Keyword(s):

Ionic Liquid ◽

Plant Hormones ◽

High Performance ◽

Extraction Solvent ◽

Target Analytes ◽

Relative Standard ◽

Ultrasound Assisted ◽

Dispersive Liquid Liquid Microextraction ◽

Liquid Microextraction

An ultrasound-assisted ionic liquid based dispersive liquid-liquid microextraction (UA-IL-DLLME) was developed for the determination of four plant hormones (6-benzyladenine (6-BA), kinetin (6-KT), 2, 4-dichlorophenoxy acetic acid (2, 4-D) and uniconazole (UN)) in soil, using high performance liquid chromatography (HPLC)-diode array detection (DAD). Several important parameters including the type and volume of extraction solvent, the volume of disperser solvent, ultrasound time, pH of the solution and salt effect were studied and optimized. Under optimum conditions, the limits of detections (LODs) for the target analytes were in the range of 0.002-0.01 μg g-1. And satisfactory recoveries of the target analytes in the soil samples were 79.3-96.7 %, with relative standard deviations (RSD, n=5) that ranged from 4.3 to 6.7%.

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Use of Dispersive Liquid-Liquid Microextraction and UV-Vis Spectrophotometry for the Determination of Cadmium in Water Samples

Journal of Spectroscopy ◽

10.1155/2014/832398 ◽

2014 ◽

Vol 2014 ◽

pp. 1-4 ◽

Cited By ~ 5

Author(s):

J. Pérez-Outeiral ◽

E. Millán ◽

R. Garcia-Arrona

Keyword(s):

Water Samples ◽

Limit Of Detection ◽

Experimental Conditions ◽

Cadmium Determination ◽

A Value ◽

Relative Standard ◽

Potential Applicability ◽

Dispersive Liquid Liquid Microextraction ◽

Liquid Microextraction

A simple and inexpensive method for cadmium determination in water using dispersive liquid-liquid microextraction and ultraviolet-visible spectrophotometry was developed. In order to obtain the best experimental conditions, experimental design was applied. Calibration was made in the range of 10–100 μg/L, obtaining good linearity (R2 = 0.9947). The obtained limit of detection based on calibration curve was 8.5 μg/L. Intra- and interday repeatability were checked at two levels, obtaining relative standard deviation values from 9.0 to 13.3%. The enrichment factor had a value of 73. Metal interferences were also checked and tolerable limits were evaluated. Finally, the method was applied to cadmium determination in real spiked water samples. Therefore, the method showed potential applicability for cadmium determination in highly contaminated liquid samples.

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Determination of the Optimal Concentration of Valproic Acid in Patients with Epilepsy: A Population Pharmacokinetic-Pharmacodynamic Analysis

PLoS ONE ◽

10.1371/journal.pone.0141266 ◽

2015 ◽

Vol 10 (10) ◽

pp. e0141266 ◽

Cited By ~ 17

Author(s):

Hiroo Nakashima ◽

Kentaro Oniki ◽

Miki Nishimura ◽

Naoki Ogusu ◽

Masatsugu Shimomasuda ◽

...

Keyword(s):

Valproic Acid ◽

Optimal Concentration ◽

Population Pharmacokinetic ◽

Pharmacodynamic Analysis ◽

Patients With Epilepsy

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Sensitive Determination of Terazosin in Pharmaceutical Formulations and Biological Samples by Ionic-Liquid Microextraction Prior to Spectrofluorimetry

International Journal of Analytical Chemistry ◽

10.1155/2012/546282 ◽

2012 ◽

Vol 2012 ◽

pp. 1-7 ◽

Cited By ~ 7

Author(s):

Mohsen Zeeb ◽

Mahdi Sadeghi

Keyword(s):

Ionic Liquid ◽

Ionic Strength ◽

Biological Samples ◽

Limit Of Detection ◽

Pharmaceutical Formulations ◽

Experimental Conditions ◽

Relative Standard ◽

Common Ion ◽

Liquid Microextraction

An efficient and environmentally friendly sample preparation method based on the application of hydrophobic 1-Hexylpyridinium hexafluorophosphate [Hpy][PF6] ionic liquid (IL) as a microextraction solvent was proposed to preconcentrate terazosin. The performance of the microextraction method was improved by introducing a common ion of pyridinium IL into the sample solution. Due to the presence of the common ion, the solubility of IL significantly decreased. As a result, the phase separation successfully occurred even at high ionic strength, and the volume of the settled IL-phase was not influenced by variations in the ionic strength (up to 30% w/v). After preconcentration step, the enriched phase was introduced to the spectrofluorimeter for the determination of terazosin. The obtained results revealed that this system did not suffer from the limitations of that in conventional ionic-liquid microextraction. Under optimum experimental conditions, the proposed method provided a limit of detection (LOD) of 0.027 μg L−1and a relative standard deviation (R.S.D.) of 2.4%. The present method was successfully applied to terazosin determination in actual pharmaceutical formulations and biological samples. Considering the large variety of ionic liquids, the proposed microextraction method earns many merits, and will present a wide application in the future.

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Vortex-Assisted Dispersive Liquid–Liquid Microextraction Coupled with Deproteinization for Determination of Nateglinide in Human Plasma Using HPLC/UV

Journal of Chromatographic Science ◽

10.1093/chromsci/bmaa096 ◽

2020 ◽

Author(s):

Mohamed A Hammad ◽

Amira H Kamal ◽

Reham E Kannouma ◽

Fotouh R Mansour

Keyword(s):

Human Plasma ◽

High Performance ◽

Limit Of Detection ◽

Signal To Noise Ratio ◽

Cost Effective ◽

Salt Addition ◽

Relative Standard ◽

Dispersive Liquid Liquid Microextraction ◽

Liquid Microextraction

Abstract A validated method for preconcentration and determination of nateglinide in plasma was developed using vortex-assisted dispersive liquid–liquid microextraction. Different variables that affect extraction efficiency were studied and optimized, including type and volume of extractant, type and volume of disperser, pH of diluent, salt addition effect, centrifugation and vortex time. Nateglinide was extracted using 30 μL of 1-octanol as an extractant and 200 μL of methanol as a disperser. The enrichment factor reached 330 under the optimum conditions. High-performance liquid chromatography/ultraviolet was used for detection using phosphate buffer (pH 2.5, 10 mM): acetonitrile (45:55, v/v) as a mobile phase at a flow rate of 1 mL/min. The method was linear over the range of 50–20,000 ng/mL with a limit of detection of 15 ng/mL (signal-to-noise ratio = 3). Intra- and inter-day precision had %relative standard deviation <6% (n = 3) and the %recoveries were found to be between 102.5 and 105.9%. The proposed method is simple, sensitive, eco-friendly, cost-effective and powerful for microextraction of nateglinide from human plasma samples.

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