Fluorescence detection of vitamin B12 in human plasma and urine samples using silver nanoparticles embedded in chitosan in micellar media

2017 ◽  
Vol 9 (27) ◽  
pp. 4052-4059 ◽  
Author(s):  
Nahid Pourreza ◽  
Roya Mirzajani ◽  
Jafar Burromandpiroze
Keyword(s):  
Silver Nanoparticles ◽  
Vitamin B12 ◽  
Nonionic Surfactant ◽  
Human Plasma ◽  
Fluorescence Detection ◽  
Cloud Point Extraction ◽  
Micellar Media ◽  
Plasma And Urine Samples ◽  
Triton X

A novel fluorescence method has been developed for the determination of vitamin B12. The method is based on the interaction of vitamin B12 with silver nanoparticles embedded in chitosan (AgNPs–CH) followed by cloud point extraction using Triton X-100 as the nonionic surfactant.

scholarly journals Determination of Antidepressants in Human Plasma by Modified Cloud-Point Extraction Coupled with Mass Spectrometry

2020 ◽  
Vol 13 (12) ◽  
pp. 458
Author(s):  
Elżbieta Gniazdowska ◽  
Natalia Korytowska ◽  
Grzegorz Kłudka ◽  
Joanna Giebułtowicz
Keyword(s):  
Mass Spectrometry ◽  
Simultaneous Determination ◽  
Human Plasma ◽  
Cloud Point ◽  
Extraction Efficiency ◽  
Cloud Point Extraction ◽  
Limiting Factor ◽  
Drug Determination ◽  
Triton X

Cloud-point extraction (CPE) is rarely combined with liquid chromatography coupled to mass spectrometry (LC–MS) in drug determination due to the matrix effect (ME). However, we have recently shown that ME is not a limiting factor in CPE. Low extraction efficiency may be improved by salt addition, but none of the salts used in CPE are suitable for LC–MS. It is the first time that the influences of a volatile salt—ammonium acetate (AA)—on the CPE extraction efficiency and ME have been studied. Our modification of CPE included also the use of ethanol instead of acetonitrile to reduce the sample viscosity and make the method more environmentally friendly. We developed and validated CPE–LC–MS for the simultaneous determination of 21 antidepressants in plasma that can be useful for clinical and forensic toxicology. The selected parameters included Triton X-114 concentration (1.5 and 6%, w/v), concentration of AA (0, 10, 20 and 30%, w/v), and pH (3.5, 6.8 and 10.2). The addition of 10% of AA increased recovery twice. For 20 and 30% (w/v) of AA, three phases were formed that prolonged the extraction process. The developed CPE method (6% Triton X-114, 10% AA, pH 10.2) was successfully validated through LC–MS/MS simultaneous determination of 21 antidepressants in human plasma. The linearity was in the range of 10–750 ng/mL (r2 > 0.990).

Development and Validation of a New Method for the Determination of Anti-hepatitis C Agent Simeprevir in Human Plasma using HPLC with Fluorescence Detection

2020 ◽  
Vol 16 (4) ◽  
pp. 428-435
Author(s):  
Ahmed F.A. Youssef ◽  
Yousry M. Issa ◽  
Kareem M. Nabil
Keyword(s):  
Hepatitis C ◽  
Human Plasma ◽  
Fluorescence Detection ◽  
Internal Standard ◽  
Protein Precipitation ◽  
Assay Method ◽  
Fluorescence Detector ◽  
Limit Of Quantification ◽  
Relative Standard

Background: Simeprevir is one of the recently discovered drugs for treating hepatitis C which is one of the major diseases across the globe. Objective: The present study involves the development of a new and unique High-Performance Liquid Chromatography (HPLC) method using fluorescence detection for the determination of simeprevir (SIM) in human plasma. Methods: Two methods of extractions were tested, protein precipitation using acetonitrile and liquidliquid extraction. A 25 mM dipotassium hydrogen orthophosphate (pH 7.0)/ACN (50/50; v/v), was used as mobile phase and C18 reversed phase column as the stationary phase. The chromatographic conditions were optimized and the concentration of simeprevir was determined by using the fluorescence detector. Cyclobenzaprine was used as an internal standard. Results: Recovery of the assay method based on protein precipitation was up to 100%. Intra-day and inter-day accuracies range from 92.30 to 107.80%, with Relative Standard Deviation (RSD) range 1.65-8.02%. The present method was successfully applied to a pharmacokinetic study where SIM was administered as a single dose of 150 mg SIM/capsule (Olysio®) to healthy individuals. Conclusion: This method exhibits high sensitivity with a low limit of quantification 10 ng mL-1, good selectivity using fluorescence detection, wide linear application range 10-3000 ng mL-1, good recovery and highly precise and validation results. The developed method can be applied in routine analysis for real samples.

scholarly journals Determination of ultra-trace levels of palladium in water samples by cloud point extraction and graphite furnace atomic absorption spectrometry

2021 ◽  
pp. 174751982110273
Author(s):  
Quan Han ◽  
Yanyan Huo ◽  
Xiaohui Yang ◽  
Xing Yao
Keyword(s):  
Water Samples ◽  
Cloud Point Extraction ◽  
Graphite Furnace ◽  
Chelating Agent ◽  
Absorption Spectrometry ◽  
Graphite Furnace Atomic Absorption ◽  
Ultra Trace ◽  
Triton X ◽  
Optimized Conditions

A highly sensitive method for the determination of ultra-trace levels of palladium in water samples by cloud point extraction and graphite furnace atomic absorption spectrometry is developed. The procedure is based on complexation of palladium with a laboratory-prepared novel chelating agent, 2-(5-bromo-4-methyl-2-pyridylazo)-5-dimethylaminoaniline (5-Br-4-CH3-PADMA) and subsequent micelle-mediated extraction of the product using the non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114) as an extracting agent. Analytical parameters affecting the separation and detection process, such as pH, concentration of the chelating agent and surfactant, equilibration temperature, and time are investigated. The optimized conditions are as follows: pH 6.0 HAc–NaAc buffer solution, 1 × 10−5 mol L−1 5-Br-4-CH3-PADMA, and 0.1% (w/v) Triton X-114. Under the optimized conditions, the calibration graph is linear in the range of 0.1–12 ng/mL, the detection limit is 0.05 ng/mL for palladium, and the relative standard deviation is 2.9% ( c = 1.0 ng/mL, n = 10). The enrichment factor, defined as the ratio of the aqueous solution volume to that of the surfactant-rich phase volume after dilution with HNO3–methanol solution, is 200. The proposed method is applied to the determination of palladium in water samples with satisfactory results.

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