A simple, rapid, and sensitive flow injection spectrophotometric system for
determination of tetracycline hydrochloride (TCH) in pharmaceutical products. The
method is based on diazotization of 2-aminopyridine and subsequent coupling with
tetracycline hydrochloride in alkaline medium. The formed azo-dye showed maximum
absorbance at 388 nm and the calibration curve in the linear range of 25.0-150.0 μg/ml
of tetracycline hydrochloride with correlation coefficient 0.9988, while the detection
limit was 10 μg/ml and sample frequency 123 samples/hour. The accuracy and
precision data for determination of TCH by flow injection analysis method for triplicate
injection at three concentration levels(25, 80 and 150 μg/ml) the relative standard
deviation (RSD %) are 1.04, 0.247 and 1.75%, and relative error percent (Erel) are -
3.92, +1.06 and -1.9%. The proposed method was successfully applied to the
determination of tetracycline hydrochloride in pharmaceutical products. The results
obtained were in good agreement with those obtained by reference method.