Sharif Digital Repository

We describe a nanocomposite prepared from polydopamine, silver nanoparticles, and polypyrrole (PDA-Ag-PPy) that can be used for the microextraction in packed syringe (MEPS) of tricyclic antidepressants from urine samples. The PDA-Ag-PPy composite was prepared in-situ by the reduction of silver ion - doped PPy during oxidative polymerization of dopamine. The PDA-Ag coatings on the nanoribbon – shaped PPy represent a highly porous, inorganic–organic hybrid nanomaterial that has a wide range of applications. The nanocomposite was characterized by FTIR and scanning electron microscopy. It is shown to be an efficient sorbent for the MEPS of the tricyclic antidepressants amitriptyline, imipramine... 

A rapid, convenient and reliable method for microextraction in packed syringe (MEPS) of the loop diuretic furosemide (FUR) in urine along with high-performance liquid chromatography (HPLC) was developed. A nanocomposite based on silver nanoparticles/polyaniline (Ag-NPs/PANI) was synthesized and used as the MEPS packing material. This nanocomposite was prepared conveniently using interfacial polymerization without the need for any templates or functional dopants. The feasibility of the synthesized nanocomposites was examined by isolation of FUR from diluted urine samples. After extraction, the analyte was desorbed by 200 μL of methanol. It was then dried and the residue was dissolved in 30 μL... 

A novel method based on microextraction in packed syringe (MEPS) as sample preparation technique coupled off-line with gas chromatography-mass spectrometry was developed using electrospun nanofibers as sorbent. For electrospinning of polypyrrole/polyamide-based nanofiber, a homogeneous solution containing nylon 6, ferric chloride and pyrrole monomer was prepared and then was drawn into a 2.5-mL syringe. By applying a voltage of 13akV between the needle of the syringe and an aluminum-foil collector, the nanofibers could be formed on the surface of the collector. The prepared sheet was used as the sorbent for MEPS to analyze some selected organophosphorous pesticides. Important parameters... 

An imprinted interpenetrating polymer network (IPN) was synthesized and used as a medium for isolation of carbamazepine from urine samples. The polymer network consisted of a homogeneous polystyrene–sol gel hybrid constructed by in–situ radical polymerization method. In this process, within the sol–gel reaction duration, styrene monomer could penetrate into the reaction mixture and after the polymerization initiation, a monolithic IPN structure was prepared. The scanning electron microscopy (SEM) image and energy dispersive spectroscopy (EDX) are indications of the polystyrene dispersion at nano- to micro-meter level in the sol gel matrix. Eventually, the synthesized IPN was used as a... 

Microbial fuel cells (MFCs) have been a potential green energy source for a long time but one of the problems is that either the technology must be used on a large scale or special equipment have been necessary to keep the fuel cells running such as syringe pumps. Paper-based microbial fuel cells do not need to have a syringe pump to run and can run entirely by themselves when placed in contact with the fluids that are necessary for it to run. Paper-based microbial fuel cells are also more compact than traditional MFCs since the device doesn't need any external equipment to run. The goal of this paper is to develop a microbial fuel cell that does not require a syringe pump to function. This... 

In salting-out liquid-liquid extraction (SALLE) technique, water-miscible organic solvents are used for extraction of polar analytes from saline solutions. In this study, for the first time, a coupled 1-mL syringes system was utilized to perform a miniaturized SALLE method. Sulfanilamide antibiotic was extracted and determined via the developed method followed by high performance liquid chromatography-ultraviolet detection (HPLC-UV). The extraction process was carried out by rapid shooting of acetonitrile as extraction solvent (syringe B) into saline aqueous sample solution (syringe A), and then the shooting was repeated several times at a rate of 1 cycle s-1. Thereby, an extremely large... 

A simple, rapid and sensitive method based on microextraction in packed syringe (MEPS), in combination with gas chromatography-mass spectrometry (GC-MS) was developed. Polyaniline (PANI) nanowires network was synthesized and used as sorbent of MEPS for the multiresidue determination of selected analytes from triazine, organochlrorine and organophosphorous pesticides in aqueous samples. The PANI nanowires network was prepared using soft template technique and its characterization was studied by scanning electron microscopy (SEM). The presence of micelles in this methodology showed to be an important parameter in shaping the growing polymer. Hexadecyltrimethylammonium bromide (HTAB) was used... 

A novel method based on microextraction in packed syringe (MEPS), as a sample preparation technique in combination with gas chromatography-mass spectrometry (GC-MS) was developed using a polypyrrole (PPy) nanowires network as the extracting medium. The PPy nanowires network was prepared using a soft template technique and its characterization was studied by scanning electron microscopy (SEM). The use of micelles in this methodology has an important role in the shape of the growing polymer. The pyrrole monomer was introduced into cetyltrimethylammonium bromide (CTAB) micelles and this has led to the formation of nanowires with diameters ranging from 30 to 60 nm. The bulk PPy prepared without... 

Reinforced polydiphenylamine (PDPA) nanocomposite was synthesized by oxidation of diphenylamine in 4molL-1 sulfuric acid solution containing a fixed amount of carbon nanotubes (CNTs) in the presence of cetyltrimethylammonium bromide (CTAB). The surface characteristic of PDPA and PDPA/CNT nanocomposites was investigated using scanning electron microscopy (SEM). The prepared PDPA/CNT nanocomposite was used as an extraction medium for microextraction in packed syringe (MEPS) of selected pesticides from aquatic environment. The effect of CNT doping level and the presence of surfactant on the extraction capability of nanocomposite was investigated and it was revealed that when 4% (w/w) of CNT in... 

Porous gelatin-chitosan microcarriers (MCs) with the size of 350 ± 50 μm were fabricated with blends of different gelatin/chitosan (G/C) weight ratio using an electrospraying technique. Response surface methodology (RSM) was used to study the quantitative influence of process parameters, including blend ratio, voltage, and syringe pump flow rate, on MCs diameter and density. In the following, MCs of the same diameter and different G/C weight ratio (1, 2, and 3) were fabricated and their porosity and biocompatibility were investigated via SEM images and MTT assay, respectively. The results showed that mesenchymal stem cells (MSCs) could attach, proliferate, and spread on fabricated porous MCs...