The use of dissolvable layered double hydroxide components in an in situ solid-phase extraction for chromatographic determination of tetracyclines in water and milk samples.
An accurate, convenient and fast method was proposed for the determination of tetracyclines (tetracycline, chlortetracycline, oxytetracycline, doxycycline and methacycline) and their preparations by flow injection detector based on tetracycline flow-through sensor. The parameters affecting the measurement were discussed. The detector can respond to tetracycline, chlortetracycline, oxytetracycline, doxycycline and methacycline, at the same time. Their slopes are 51-55 mV/decade over the concentration range of 10(-2)-5 x 10(-5) mol/L at pH 1.5-3.5. The results obtained are in good agreement with those by biological assay (less than 3% deviation). One hundred samples can be determined in an hour.