Chemiluminescence determination of tetracycline and oxytetracycline in pharmaceutical preparations using Ru (bipy)3 2+-cerium (IV) system

A chemiluminescence reaction consisting of manganese(IV), sodium sulfite, and sulfur- and nitrogen-doped carbon quantum dots, and its application for the determination of oxytetracycline

Sulfur- and nitrogen-doped carbon quantum dots (S,N-CQDs) were prepared by a solid-phase hydrothermal method from cysteine and citric acid and characterized by transmission electron microscopy, energy-dispersive X-ray spectroscopy, and FTIR spectroscopy. These QDs were exploited as enhancers to amplify the chemiluminescence (CL) of manganese(IV)-sodium sulfite reaction. S,N-CQDs exceptionally enhanced the CL intensity of this system, around 900-fold. This effect was attributed to the energy transfer from SO₂^*, produced by reaction of Mn(IV) with SO₃^2-, to S,N-CQDs. The maximum wavelength of CL emission was 480 nm, which confirmed that the final emitting species was S,N-CQDs. After optimization of reaction conditions, the analytical applicability of S,N-CQD-Mn(IV)-SO₃^2- CL system was studied. In the presence of oxytetracycline, the CL intensity was significantly diminished. A linear relationship was observed between CL signal and the logarithm of oxytetracycline concentration in the range of 0.075-3.0 μM with a detection limit of 25 nM. This CL assay for oxytetracycline was used for analysis of spiked milk and water samples. Graphical abstractSchematic representation of the amplified chemiluminescence (CL) reaction consisting of sulfur- and nitrogen-doped carbon quantum dots (S,N-CQDs) Mn(IV) and Na2SO3. Sub-micromolar levels of oxytetracycline can be determined by using this system.

A Critical Review of Properties and Analytical Methods for the Determination of Oxytetracyline in Biological and Pharmaceutical Matrices

Antibiotics have an unquestionable importance in the treatment of many infections. Oxytetracycline is an antibiotic belonging to the class of tetracyclines, available for use in human and veterinary medicine. Development of analytical methods that prove the quality and efficacy of these drugs is fundamentally important to the pharmaceutical industry. In this context, the research presents an overview of the analytical profile of oxytetracycline, describing its chemical and pharmacological properties, and analytical methods for quantification of this drug in biological samples and pharmaceutical products. Oxytetracycline can be analyzed in these matrices by many types of methodologies. However, high-performance liquid chromatography is the most widely used, being recommended by official compendia. This kind of study can be useful to support the development of new efficient and sustainable analytical methods that may be utilized in the quality control routine of oxytetracycline in pharmaceutical products and pharmacokinetic monitoring in biological samples.

Tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence

This paper critically reviews analytical applications of the chemiluminescence from tris(2,2'-bipyridyl)ruthenium(II) and related compounds published in the open literature between mid-1998 and October 2005. Following the introduction, which summarises the reaction chemistry and reagent generation, the review divides into three major sections that focus on: (i) the techniques that utilise this type of detection chemistry, (ii) the range of analytes that can be determined, and (iii) analogues and derivatives of tris(2,2'-bipyridyl)ruthenium(II).