Anodized Aluminum Wire as a Solid-Phase Microextraction Fiber

Abstract

The efficiency of anodized aluminum wire was investigated as a new fiber for solid-phase microextraction (SPME). Aluminum wires were anodized by direct current in a solution of sulfuric acid at room temperature and were conditioned at 300 degrees C for 30 min. These fibers were used for the extraction of some aliphatic alcohols, BTEX, and petroleum products from gaseous samples. The extracted analytes were transferred to a GC injector using an (inhouse-designed) SPME syringe that also allowed for an easy change of SPME fibers. The results obtained prove the ability of anodized aluminum wire as a new fiber for sampling of organic compounds from gaseous samples. This behavior is due most probably to the porous layer of aluminum oxide, which is formed on the metal surfaces. In this work, the optimum conditions for the preparation and conditioning of fibers and the extraction of analytes from gaseous samples were obtained. In the optimum conditions, one fiber was used in several equal analyses and the relative standard deviations were below 5% (n = 5). However, fiber-to-fiber reproducibility was 8% (n = 5). This fiber is firm, inexpensive, and durable and can be prepared simply.

The Effects of Environmental Parameters on Air Sampling with SPME from Halogenated Hydrocarbons

“…The sampling time affects the adsorption because more water molecules can be adsorbed when given more time. Some studies have reported that a more than 10% increment in relative humidity had a negative effect on the sampling capacity of SPME coatings (13,19). Our data show that humidity increase from 20 to 40% has more effect on mass of analyte absorbed by SPME compared to high humidity.…”

“…Our data show that humidity increase from 20 to 40% has more effect on mass of analyte absorbed by SPME compared to high humidity. When humidity is low, many free sites are available on fibers and water molecules are more easily adsorbed by sampler but whenever the humidity increases under the same conditions most sites have already been occupied by water molecules and there is less tendency for further adsorption of water vapor (13,19). This result is similar to a previous study that concluded that relative humidity in range of 0 to 92% has reduced the rate of sampling of amines in air in the range of 20 to 80 percent (20).…”

Application of Dispersive Liquid-Liquid Microextraction in Separation and Preconcentration of Silver prior its Determination by Flame Atomic Absorption Spectrometry

“…However, these methods suffer from the drawbacks such as time-consumption, poor enrichment factors, and large volumes of toxic organic solvents. 7 To overcome these problems, modern analytical methods including LPME 27−30 and solid phase microextraction (SPME) 31,32 have been introduced and developed. LPME can be divided into three chief types: single-drop microextraction (SDME), 33,34 hollow-fiber-based liquid phase microextraction (HF-LPME) 35 and dispersive liquid-liquid microextraction (DLLME).…”

Dispersive liquid-liquid microextraction for the simultaneous separation of trace amounts of zinc and cadmium ions in water samples prior to flame atomic absorption spectrometry determination

“…6 Several novel microextraction techniques are being developed in order to reduce the analysis step, increase the sample throughput and to improve the quality and the sensitivity of the analytical methods. The cloud point extraction (CPE), 7 the homogeneous liquid-liquid extraction (HLLE), 8,9 the liquid phase microextraction (LPME) 10,11 and the solid phase microextraction (SPME) 12,13 are fairly new methods of sample preparation. They are employed in the separation and preconcentration of environmental contaminants in different matrices and can solve some of the problems, encountered with the conventional pretreatment techniques.…”