Stir Bar Sorption Extraction (SBSE) and Its Application for Analysis of Organic Compounds in Aqueous Samples: A Review

Mesfin Medihin Ododo

doi:10.7176/cmr/13-1-01

Abstract

Sample preparation is one of the crucial steps in any chemical analysis because most samples are not ready to introduce directly into analytical instruments. This step is very important to eliminate interferences, isolate and preconcentration of analytes of interest from the matrix and makes them more suitable for separation and detection. The extraction of analytes from aqueous matrices can be traditional and nontraditional techniques. Miniaturized techniques are simple, solventless or solvent-reduced techniques allowing the extraction and concentration in a single step on a micro scale approach. Stir Bar Sorptive Extraction (SBSE) is a relatively new solventless sample preparation method for the extraction and concentration of organic compounds from aqueous matrices of environmental, food and biological samples. In SBSE, a stir bar coated with Polydimethylsiloxane (PDMS) phase is added to a vial containing the sample. The sample is then stirred until analytes partition equilibrium time reached with sorbent. The extracts can be introduced quantitatively into the analytical system by thermal or liquid desorption. The efficiency of extraction of SBSE in terms of the amount extracted and the equilibrium is affected by extraction time, stirring speed, temperature of the sample, pH, salting and sample volume. The most important limitation of SBSE is the only commercial availability of PDMS coating material exists at present. Besides, due to the non-polar character of PDMS, SBSE technique is mainly applied to extract non-polar and weakly polar compounds but failed in extraction of strongly polar compounds. Keywords : Stir Bar Sorptive Extraction, Polydimethylsiloxane, Sample Preparation, Organic Compounds DOI: 10.7176/CMR/13-1-01 Publication date: January 31 st 2021

Highlights

Sample preparation is a process required for the transformation of the analytes of interest from sample matrix into a form more suitable for introduction into the analytical instrument (Baltussen, 2000)
In Stir Bar Sorptive Extraction (SBSE), a stir bar coated with Polydimethylsiloxane (PDMS) phase is added to a vial containing the sample
2.2 Extraction Procedure The stir bar coated with PDMS phase is directly added to a vial containing the sample as shown in Figure 2 a (Kassem, 2011), or special device to hold the stir bar is available from headspace above the sample as shown in Figure 2 b (Kole et al, 2011)

Summary

Introduction

Sample preparation is a process required for the transformation of the analytes of interest from sample matrix into a form more suitable for introduction into the analytical instrument (Baltussen, 2000). It is very important to extract, isolate, and concentrate the analytes of interest from complex matrices into a suitable solvent. It has a direct impact on accuracy, precision, quantification limits and the rate-determining step of the analytical methods, especially when trace analysis is the main purpose (Feilden, 2011). The extraction of analytes from aqueous matrices can be traditional and nontraditional techniques (Jochmann, 2006). The most common traditional and the most widely used technique is liquid-liquid extraction (LLE). It is tedious, time-consuming, difficult to automate and environmentally unfriendly due to large amounts of organic solvents are required. The major drawbacks of SPE are the large sample volumes requirement and limited enrichment factor (Ochiai et al, 2008)

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