Development of in-tube solid-phase microextraction coupled to pressure-assisted CEC and its application to the analysis of propranolol enantiomers in human urine

✍ Scribed by Bo Lin; Ming-Ming Zheng; Siu-Choon Ng; Yu-Qi Feng

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 320 KB
• Volume: 28
• Category: Article
• ISSN: 0173-0835
• DOI: 10.1002/elps.200700174

✦ Synopsis

Abstract

A successful hyphenation of in‐tube solid‐phase microextraction (SPME) and pressure‐assisted CEC (pCEC) was developed by installing a poly(methacrylic acid‐co‐ethylene glycol dimethacrylate) monolithic capillary to the six‐port valve in a CEC system. The device designed was appropriate for on‐line in‐tube SPME coupled to pCEC or μHPLC. The evaluation of this hyphenation was first carried out for in‐tube SPME‐μHPLC with analytical capillaries packed with 3 μm octadecyl silica (ODS). Theobromine (TB), theophylline (TP), and caffeine (CA) were chosen as model drugs for an easy comparison with the results obtained by in tube SPME‐HPLC. The detection limits of these three analytes were improved more than 100 times when compared with the direct analysis by μHPLC. Then in‐tube SPME‐pCEC with CEC capillaries packed with perphenylcarbamoylated β‐CD‐bonded silica particles was applied to the determination and analysis of propranolol enantiomers in human urine. Under optimal extraction and separation conditions, the experimental LODs were 4 and 7 ng/mL for (S)‐propranolol and (R)‐propranolol, respectively. The calibration curves showed good linearity for both (S)‐propranolol (R^2^ = 0.9997) and (R)‐propranolol (R^2^ = 0.9996) over the concentration range from 20 to 5000 ng/mL. Reproducibility of the method was also investigated with intra‐ and interday precisions lower than 10% for both enantiomers at different concentration levels.