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

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 muHPLC. The evaluation of this hyphenation was first carried out for in-tube SPME-muHPLC with analytical capillaries packed with 3 microm 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 muHPLC. Then in-tube SPME-pCEC with CEC capillaries packed with perphenylcarbamoylated beta-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.

Monolith as a new sample preparation material: Recent devices and applications

“…This strategy was first applied to the extraction of phenols in an aqueous sample by Svec and co‐workers 49. Extraction using a monolith was first carried out on the basis of this approach, and many articles were published thereafter 49, 53–56, 61, 72–107. The published applications are listed in Tables 2–5.…”

“…Furthermore, separation stability and efficiency will decrease when SPE is combined with CE. Several inline preconcentration techniques have been reported 52, 57, 66, 80, 116–138, and they are listed in Table 6. An inline preconcentration column can be formed by constructing a small monolith bed at the end of a CE capillary or by coupling a short monolith capillary column to the inlet of a CE capillary.…”

Microextraction sample preparation techniques in biomedical analysis

“…This method is used in combination with HPLC and CE in the analysis of tricyclic antidepressants in urine . Recently described applications of these techniques for drug analysis are summarized in Table .…”

Hyphenation in sample preparation: Advancement from the micro to the nano world

“…Lin et al [49] described hyphenation of in-tube solidphase micro-extraction (SPME) and pressure-assisted CEC (p-CEC) by installing a poly(methacrylic acid-co-ethylene glycol dimethacrylate) monolithic capillary at a six-port valve in a CEC system. Theobromine, theophylline, and caffeine were chosen as model drugs to facilitate comparison with the results obtained by in-tube SPME -HPLC.…”