Determination of antibiotic drug concentrations in circulating human blood by means of solid phase micro-extraction

• Published in: Clinica chimica acta 2007-11, Vol.386 (1), p.57-62
• Main Authors: Schubert, Jochen K., Miekisch, Wolfram, Fuchs, Patricia, Scherzer, Nadja, Lord, Heather, Pawliszyn, Janusz, Mundkowski, Ralf G.
• Format: Article
• Language: English
• Subjects: Acetamides - blood; Acetamides - chemistry; Anti-Bacterial Agents - blood; Anti-Bacterial Agents - chemistry; Antibiotics; Blood Circulation - physiology; Chromatography, High Pressure Liquid - methods; Creatinine - blood; Drug monitoring; Hemoglobins - analysis; Hemoglobins - metabolism; Humans; In vivo solid phase micro-extraction; L-Lactate Dehydrogenase - blood; Linear Models; Linezolid; Oxazolidinones - blood; Oxazolidinones - chemistry; Reproducibility of Results; Sensitivity and Specificity; Solid Phase Extraction - methods; Time Factors
• ISSN: 0009-8981; 1873-3492
• DOI: 10.1016/j.cca.2007.07.024

Promising results in animals have shown the diagnostic potential of polypyrrole coated SPME fibres introduced directly into the blood stream. This study was intended to extend this technique to a clinically relevant antibiotic drug under close to physiological conditions in human blood. An artificial vein system was built up from heart and lung machine components. Determination of Linezolid (0–15 μg/mL) was performed by SPME from the flowing system (“online”, flow velocities 2–50 cm/s), from blood withdrawn from the system (“offline”) and by means of a SPE/HPLC method. SPME was done using new fibres (“new”) for each analysis, and in the way that one fibre was reused (“re”) for one series of measurements. Drug SPME did not depend on blood flow velocities. Linear regression of data (concentration vs. amount extracted) yielded R 2 = 0.998 for SPE/HPLC, R 2 = 0.955 for SPME online_new, 0.929 for SPME online_re, 0.929 SPME offline_new, 0.973 for SPME offline_re, RSD were 52% (SPME online_new), 10% (SPME online_re), 47% (SPME offline_new), 18% (SPME offline_re), 8% (SPE/HPLC). In-vein SPME has the potential to minimize blood requirement for diagnostic purposes and to speed up analysis of clinically relevant drugs, if inter-fibre variation can be reduced through standardized manufacturing.