Preface

Book "Advances in Nanofibers" is a research publication that covers original research on developments within the Nanofibers field of study. The book is a collection of reviewed scholarly contributions written by different authors. Each scholarly contribution represents a chapter and each chapter is complete in itself but related to the major topics and objectives. The chapters included in the book are: Electrospun Nanofiber Based Solid Phase Extraction, Electrospun Nanofibers: From Rational Design, Fabrication to Electrochemical Sensing Ap‐ plications, Chitin Nanofibers, Preparations and Applications, Fabrication of Nanofibrous Scaffolds by Electrospinning, Carbon Nanofiber Concrete for Damage Detection of Infra‐ structure, Materials and Processes for Ion Permeable Separating Membranes by Electro-Spinning, Nanofibers Reinforced Polymer Composite Microstructures, Use of Self-Assembly Nanofibre Biomaterials for Neural Repair After Injury. The target audience comprises schol‐ ars and specialists in the field.

#### **Dr. Russell Maguire**

Boeing Technical Fellow, President, Global Nanocomposites LLC Bellevue WA, USA

**Chapter 1**

**Electrospun Nanofiber Based Solid Phase Extraction**

The objectives of a sample preparation technique in Analytical Chemistry are twofold; transformation of a sample into a form that is suitable for instrumental analysis and to ensure that the sample is at the detection level for the instrument of choice. Solid phase extraction (SPE) is a popular sample preparation technique for liquid samples with subsequent chroma‐ tographic analysis [1]. SPE is employed with the aim of either reducing interferences or achieving analyte preconcentration in order to enhance instrumental detection. Although SPE can be described as a physical extraction process involving a liquid phase and a solid phase (that can be packed or free flowing sorbent), the increased use of packed sorbent formats seems to have led to a bias towards packed sorbent SPE devices [2]. One of the first applications of packed sorbent SPE was reported in 1951, when Braus and co-workers packed 1.2-1.5 kg of granular activated carbon into an iron cylinder for the isolation of organic compounds [3]. Since then, there has been significant progress in SPE technology, as evidenced by reports on new formats and sorbents covering a wide range of morphologies and chemistries [1].

SPE research and developments have progressed with a focus on SPE device fabrication or SPE method development. In principle, the heart of the SPE technique is the sorbent material as it has a direct influence on the selectivity, sorptive capacity and the format or the configu‐

To predict and optimize extraction, it is important to be aware of the nature of the sorbent used with respect to physicochemical characteristics. The most important physicochemical charac‐ teristics for optimal extraction are porosity, specific surface area and surface chemistry.

Given that there will always be a need for new sorbent materials, it is imperative to focus research efforts on versatile sorbent fabrication techniques that could address current and anticipated challenges. Electrospinning is seen as having great potential as a sorbent fabrica‐

> © 2013 Chigome and Torto; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

Samuel Chigome and Nelson Torto

http://dx.doi.org/10.5772/57100

ration of the resultant SPE device (s).

tion technique, given its versatility [4].

**1. Introduction**

Additional information is available at the end of the chapter
