A Flow-Based Analytical Procedure for Salbutamol Determination Exploiting Chemiluminescence in a Liquid-Core Waveguide

Abstract

Salbutamol is a bronchodilator whose use is restricted due to its anabolic effects. A flow-based procedure for salbutamol determination based on the inhibition of chemiluminescence of the luminol/hypochlorite system was developed. A flow cell constructed with a liquid-core waveguide was employed to constrain the emitted radiation, minimizing losses during transport to detector. Linear response was observed within 2.5 × 10⁻⁶ and 1.0 × 10⁻⁵ mol L⁻¹ with a detection limit estimated as 1 × 10⁻⁷ mol L⁻¹ at the 99.7% confidence level. The coefficient of variation (n = 20), sampling rate, and luminol consumption per determination were estimated as 2.8%, 164 determinations h⁻¹, and 50 µg, respectively. Results for pharmaceutical samples were in agreement with those obtained by reference procedures at the 95% confidence level.

Keywords:

• Chemiluminescence
• FIA
• hypochlorite
• liquid-core waveguide
• salbutamol

The authors acknowledge the fellowships and financial support from the Brazilian agencies Conselho Nacional de Pesquisa e Desenvolvimento (CNPq) and Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP-proc. n^o 05/53345-9). F.S. Felix is thanked for her help in the measurements by capillary electrophoresis.

Notes

concentrations in mg mL⁻¹ (samples 1–3) or mg g⁻¹ (sample 4).

CE-C⁴D = capillary electrophoresis with contactless conductivity detection; CE-FASI = capillary electrophoresis with field-amplified sample injection; SPE-SIA = solid-phase extraction coupled to sequential injection analysis; MIP-CL flow sensor = chemiluminescence flow sensor using molecularly imprinted polymer; FIA = flow injection analysis; N.A. = not available.