Table 1.

Detection in tetracycline, doxycycline, and minocycline of catechol-phenolate-like and hydroxamate-like groups

AntibioticaA510in Arnow assay for catechol-phenolateA526 in Csaky assay for hydroxamate
Tetracycline0.07 ± 0.020.54 ± 0.09
Doxycycline0.04 ± 0.030.25 ± 0.04
Minocycline1.23 ± 0.091.44 ± 0.11
Positive controlb 2.82 ± 0.142.71 ± 0.09
Negative controlc 00.04 ± 0.02
  • a Antibiotics were used at 1 mg/ml.

  • b 2,3-Dihydroxybenzoic acid (1 mg/ml) for the Arnow assay and hydroxylamine hydrochloride (1 mg/ml) for the Csaky assay.

  • c Distilled water.