repeatability (% RSD 3.17–2.18). The advantage of the proposed
method is simple and time saving because the cleaning
step occurs simultaneously during the measurement. The
commercial drugs of doxycycline hydrochloride or chlortetracycline
hydrochloride were also analyzed by proposed
methods.
Acknowledgements
Acknowledgements are made to the Thailand Research
Fund (Research Team Promotion Grant) and the
Ratchadaphisek Somphot Endowment Grant, Chulalongkorn
University.