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

• Published in: Journal of chromatography. B, Analytical technologies in the biomedical and life sciences Vol. 801; no. 2; pp. 317 - 321
• Main Author: Abdel-Rehim, Mohamed
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05.03.2004; Elsevier Science
• Subjects: Anaesthetics; Analysis; Analytical, structural and metabolic biochemistry; Anesthetics, Local - blood; Biological and medical sciences; Computers; Fundamental and applied biological sciences. Psychology; Gas Chromatography-Mass Spectrometry - methods; General pharmacology; Humans; Medical sciences; Microextraction in packed syringe; Miniaturization; Pharmacology. Drug treatments; Polymers; Reproducibility of Results; Sensitivity and Specificity; Specimen Handling - instrumentation; Specimen Handling - methods; Syringes; Microextraction in packed syringe; Anaesthetics; Local anesthetic; Human; Gas chromatography; Biological fluid; Spectrometry; Gas liquid chromatography; Quantitative analysis; Blood plasma
• ISSN: 1570-0232; 1873-376X
• DOI: 10.1016/j.jchromb.2003.11.042

A new technique for sample preparation on-line with LC and GC–MS assays was developed. Microextraction in a packed syringe (MEPS) is a new miniaturised, solid-phase extraction technique that can be connected on-line to GC or LC without any modifications. In MEPS approximately 1 mg of the solid packing material is inserted into a syringe (100–250 μl) as a plug. Sample preparation takes place on the packed bed. The bed can be coated to provide selective and suitable sampling conditions. The new method is very promising. It is very easy to use, fully automated, of low cost and rapid in comparison with previously used methods. This paper presents the development and validation of a method for microextraction in packed syringe MEPS on-line with GC–MS. Local anaesthetics in plasma samples were used as model substances. The method was validated and the standard curves were evaluated by the means of quadratic regression and weighted by inverse of the concentration: 1/ x for the calibration range 5–2000 nM. The applied polymer could be used more than 100 times before the syringe was discarded. The extraction recovery was between 60 and 90%. The results showed close correlation coefficients ( R>0.99) for all analytes in the calibration range studied. The accuracy of MEPS–GC–MS was between 99 and 115% and the inter-day precision ( n=3 days), expressed as the relative standard deviation (R.S.D.%), was 3–10%.