Latifa Latrous El Atrache

Bio: Latifa Latrous El Atrache is an academic researcher from Tunis University. The author has contributed to research in topics: Solid phase extraction & Extraction (chemistry). The author has an hindex of 5, co-authored 11 publications receiving 140 citations.

TiO2 nanotubes as solid-phase extraction adsorbent for the determination of polycyclic aromatic hydrocarbons in environmental water samples

Abstract: An analytical method based on TiO2 nanotubes solid-phase extraction (SPE) combined with gas chromatography (GC) was established for the analysis of seven polycyclic aromatic hydrocarbons (PAHs): acenaphtylene, acenaphthene, anthracene, fluorene, phenanthrene, fluoranthene and pyrene. Factors affecting the extraction efficiency including the eluent type and its volume, adsorbent amount, sample volume, sample pH and sample flow rate were optimized. The characteristic data of analytical performance were determined to investigate the sensitivity and precision of the method. Under the optimized extraction conditions, the method showed good linearity in the range of 0.01-0.8 microg/mL, repeatability of the extraction (RSD were between 6.7% and 13.5%, n = 5) and satisfactory detection limits (0.017-0.059 ng/mL). The developed method was successfully applied to the analysis of surface water (tap, river and dam) samples. The recoveries of PAHs spiked in environmental water samples ranged from 90% to 100%. All the results indicated the potential application of titanate nanotubes as solid-phase extraction adsorbents to pre-treat water samples.

A Combination of Factorial Design, Off-line SPE and GC–MS Method for Quantifying Seven Endocrine Disrupting Compounds in Water

Abstract: A sensitive and reliable analytical method for the simultaneous determination of seven endocrine disrupting compounds (EDCs) in water was developed and validated. This quantification method is based on solid phase extraction (SPE) followed by a derivatization with BSTFA and finally the seven EDCs were analyzed by gas chromatography–mass spectrometry (GC–MS). A 23 factorial design was used to optimize the extraction procedure. Three factors, namely sample volume, elution solvent, and pH of sample were investigated using Doehlert matrix. The optimal conditions of SPE method were: HLB cartridge, 540 mL of water sample with a pH 8 and 10 mL of mixture of ethyl acetate/acetone with a ratio of (55/45, v/v) in the elution step. For validation of the technique, accuracy, precision, detection and quantification limits, linearity, sensibility and selectivity were determined. Extraction recovery of these seven EDCs were above 90% with relative standard deviations (RSD) ≤ 2%. The method limit of detection and limit of quantification were in the range of 0.33–3.33 and 1–10 ng/L, respectively.

Solid-phase extraction of organic compounds: A critical review (Part I)

Abstract: Solid-phase extraction (SPE) is the most widely used method for the extraction, changing of solvents, cleanup, concentration, and fractionation of organic compounds from a number of samples. This procedure is also very useful for desalting proteins and sugar samples. However, most SPE procedures are still poorly developed, with little consideration to the physics involved in the process and are described as largely empirical, labor-intensive, and time-consuming trial-and-error processes, without much systematization. The objective of this study is to propose a number of contradictions, disagreements, failings, and shortcomings of the SPE procedures found elsewhere. The different arguments introduced in this study attempt to challenge the suitability of this procedure, particularly when it is conducted in the traditional manner (under gravity and at a high flow rate). The first part of this study focuses on describing the state-of-the-art in SPE and its physical fundamentals.