Combination of New Solid/Liquid Phase Microextraction Technique Based on Functionalized Multiwalled Carbon Nanotubes with Flame Atomic Absorption Spectroscopy for the Extraction and Determination of Zn(II) in the Environmental Samples

2012 ◽  
Vol 4 (4) ◽  
pp. 296-303
Author(s):  
Zarrin Es'haghi ◽  
Ali Sayfi ◽  
Ali Ahmadpour ◽  
Ali Akbar Tanha ◽  
Ali Samie
2019 ◽  
Vol 20 (5) ◽  
pp. 390-400 ◽  
Author(s):  
Nabil N. AL-Hashimi ◽  
Amjad H. El-Sheikh ◽  
Rania F. Qawariq ◽  
Majed H. Shtaiwi ◽  
Rowan AlEjielat

Background: The efficient analytical method for the analysis of nonsteroidal antiinflammatory drugs (NSAIDs) in a biological fluid is important for determining the toxicological aspects of such long-term used therapies. Methods: In the present work, multi-walled carbon nanotubes reinforced into a hollow fiber by chitosan sol-gel assisted-solid/ liquid phase microextraction (MWCNTs-HF-CA-SPME) method followed by the high-performance liquid chromatography-diode array detection (HPLC–DAD) was developed for the determination of three NSAIDs, ketoprofen, diclofenac, and ibuprofen in human urine samples. MWCNTs with various dimensions were characterized by various analytical techniques. The extraction device was prepared by immobilizing the MWCNTs in the pores of 2.5 cm microtube via chitosan sol-gel assisted technology while the lumen of the microtube was filled with few microliters of 1-octanol with two ends sealed. The extraction device was operated by direct immersion in the sample solution. Results: The main factors influencing the extraction efficiency of the selected NSAIDs have been examined. The method showed good linearity R2 ≥ 0.997 with RSDs from 1.1 to 12.3%. The limits of detection (LODs) were 2.633, 2.035 and 2.386 µg L-1, for ketoprofen, diclofenac, and ibuprofen, respectively. The developed method demonstrated a satisfactory result for the determination of selected drugs in patient urine samples and comparable results against reference methods. Conclusion: The method is simple, sensitive and can be considered as an alternative for clinical laboratory analysis of selected drugs.


2019 ◽  
Vol 15 (5) ◽  
pp. 447-455 ◽  
Author(s):  
Nabil N. Al-Hashimi ◽  
Anas I. Awwad ◽  
Aqeel N. Al-Hashimi ◽  
Iman A. Mansi ◽  
Rand O. Shahin ◽  
...  

Introduction: A sensitive analytical method based on functionalized multi walled carbon nanotubes reinforced hollow fiber solid/liquid phase microextraction (F-MWCNTs-HF-SLPME) forwarded with HPLC-DAD for analyzing phenazopyridine from urine is presented. Materials and Methods: The extraction of phenazopyridine is performed using specially designed FMWCNTs- HF-SLPME device constructed as follows: the functionalized multi walled carbon nanotubes (F-MWCNTs) were immobilized into the pores of 2.5 cm hollow fiber micro-tube using capillary forces and ultrasonication, then, the lumen of the micro-tube was filled with 1-octanol with two ends sealed. Subsequently, the device was placed into 10-mL of urine sample containing the analyte with agitation. After ending extraction, the device was removed, rinsed, sonicated in 250 µL of organic solvent and analyzed directly by the separation system. Results and Conclusion: Different parameters affecting the performance of the developed method were optimized. The method showed good linearity with (R2) 0.999 and good repeatability with (RSDs) from 3.7 to 0.9% at analyte concentration ranged from 0.01 to 10 µg L-1 of spiked urine samples. The limit of detection/ quantitation, LODs/LOQs was 0.02/0.09 µg L-1. In comparison with reference methods, the developed method is considered as a promising microextraction technique for determination of trace phenazopyridine in human urine using a common HPLC without further cleanup procedures.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 781 ◽  
Author(s):  
Agnieszka Sasal ◽  
Katarzyna Tyszczuk-Rotko ◽  
Magdalena Wójciak ◽  
Ireneusz Sowa

A simple, sensitive and time-saving differential-pulse adsorptive stripping voltammetric (DPAdSV) procedure using a screen-printed carbon electrode modified with carboxyl functionalized multiwalled carbon nanotubes (SPCE/MWCNTs-COOH) for the determination of diclofenac (DF) is presented. The sensor was characterized using optical profilometry, SEM, and cyclic voltammetry (CV). The use of carboxyl functionalized MWCNTs as a SPCE modifier improved the electron transfer process and the active surface area of sensor. Under optimum conditions, very sensitive results were obtained with a linear range of 0.1–10.0 nmol L−1 and a limit of detection value of 0.028 nmol L−1. The SPCE/MWCNTs-COOH also exhibited satisfactory repeatability, reproducibility, and selectivity towards potential interferences. Moreover, for the first time, the electrochemical sensor allows determining the real concentrations of DF in environmental water samples without sample pretreatment steps.


Sign in / Sign up

Export Citation Format

Share Document