Microextraction by packed sorbent

Microextraction by packed sorbent or MEPS is a miniaturised solid phase extraction technique for the purification and concentration of plasma, water, and other samples prior to analysis by techniques such as gas chromatography or high performance liquid chromatography. It should not be confused with SPME as SPME uses a different technique to purify and concentrate samples. MEPS performs the same function as SPE, namely the purification or speciation of samples, but with some significant differences:

MEPS works with much smaller samples (as small as 10µL) compared to full scale SPE which typically uses millilitres of sample. This also helps save time.

MEPS can be fully automated using an autosampler – the sample processing, extraction and injection steps are performed on-line using the same syringe. Automating SPE usually requires additional dedicated equipment.

References

• 1. M. Abdel-Rehim, AstraZeneca Application “Syringe for solid phase microextraction”, Current Patents Gazette, week 0310, WO 03019149, p. 77, (2003).

• 2. M. Abdel-Rehim, New trend in sample preparation: on-line microextraction in packed syringe for liquid and gas chromatography applications I. Determination of local anaesthetics in human plasma samples using gas chromatography-mass spectrometry, J. Chromatogr. B, 801 (2004) 317–321.

• 3. M. Abdel-Rehim, Y. Askemark, C. Norsten-Höög, K-J. Pettersson, M. Halldin, Quantification of 4-OH-2,6-Xylidine and its Conjugates in Human Urine Samples Utilising Microextraction in Packed Syringe On-line with Liquid Chromatography and Electrospray Tandem Mass Spectrometry (MEPS-LC-MS/MS), J. Liq. Chromatogr. & Relat. Technol., 29 (2006) (16), 2413–2424.

• 4. Aziza El-Beqqali, Mohamed Abdel-Rehim, Quantitative analysis of methadone in human urine samples by microextraction in packed syringe-gas chromatography-mass spectrometry (MEPS-GC-MS), J. Sep. Sci. 30 (2007) 2501–2505.

• 5. M. Abdel-Rehim, P. Skansen, C. Nilsson and M. Hassan, "Simultaneous Determination of Busulphan in Plasma Samples by Liquid Chromatography-electrospray Ionization Mass Spectrometry Utilizing Microextraction in Packed Syringe (MEPS) as On-line Sample Preparation Method ", J. Liq. Chromatogr. & Relat. Technol., 30 (2007) 3029–3041.