Extraction of polycyclic aromatic hydrocarbons and organochlorine compounds from water: A comparison between solid‐phase microextraction and stir bar sorptive extraction

Abstract

Extraction of polycyclic aromatic hydrocarbons and organochlorine compounds from water: A comparison between solid-phase microextraction and stir bar sorptive extractionThe enrichment of semi-volatile compounds from water using solid-phase microextraction (SPME) and stir bar sorptive extraction (SBSE) was compared. The investigations (analysis of PAHs and organochlorine compounds) were performed to compare SPME-GC/MS and SBSE-thermodesorption-GC/MS. Additionally, SPME fibres and stir bars were desorbed in a small volume of solvent and analysed by HPLC with fluorescence detection. This method was applied to PAHs. SBSE is more robust and under the given conditions (extraction from a 10 mL sample, 1 h exposure time of fibres and stir bars) enables higher recoveries (20.1 -97.2%) for the compounds investigated than SPME (recoveries of 6.3 -51.6%). Detection limits between 0.1 and 4.5 ng/L were calculated for the SPME-GC/MS combination, whereas the SBSE-GC/ MS combination enabled detection limits between 0.05 and 1.0 ng/L. Coupled to HPLC, the detection limits of the PAHs investigated were found to range between 1.0 and 10.0 ng/L (SPME) or between 0.3 and 2.0 ng/L (SBSE). The advantage of SPME is that the procedure can be completely automated, which is not possible when combining SBSE with GC or LC.

Sample preparation procedures for analysis of organochlorinated pollutants and PAHs in surface water samples

“…Consequently LoD values of PAHs were decreased in one order of magnitude. SBSE and SPME procedures were compared by Popp et al (Popp et al 2003). One hundred micrometer PDMS SPME fibre or a 10 mm stir bar coated with a 0.5 mm layer of PDMS was used for 10 ml of water sample during 1 h. Since SBSE is characterized by higher phase ratio (volume of water phase to the volume of the PDMS phase), it results in higher recoveries and lower LoD values than SPME.…”

“…The peak areas of the compounds in the SBSE chromatograms were 3-to 10-fold higher than those of the SPME chromatogram, and similarly LoD characteristics were better for SPME procedure (Popp et al 2003). In-tube SPME device coated with PDMS was used for preconcentration of 4 PAHs from 10 ml of water sample (Bagheri et al 2004).…”

Polydimethylsiloxane Rods for the Passive Sampling of Pesticides in Surface Waters

“…Several studies have correlated the partitioning coefficient of analytes K sw with their octanol-water distribution coefficient (K ow ) [13,[20][21][22][23][24].…”

Automation of solid‐phase microextraction

“…For GC analysis, the loaded stirrer bars are inserted into thermal desorption tubes/ liners, which can be automatically loaded and removed from a GC injection port fitted with a thermal desorption unit and a temperature programmable injector [64,67]. However, the user needs to manually transfer the stirrer bar into the sample vial and from the sample vial to the liner tray [64]. The latter step creates the possibility of losses or contamination during transfer, and also makes the technique in its current form unsuitable for the analysis of volatiles [64].…”

“…However, the user needs to manually transfer the stirrer bar into the sample vial and from the sample vial to the liner tray [64]. The latter step creates the possibility of losses or contamination during transfer, and also makes the technique in its current form unsuitable for the analysis of volatiles [64]. The approach has also been semi-automated for LC procedures [68,69].…”