Determination of thiomersal and mercurial residues by photo-degradation and flow injection analysis with luminescence probing using carbon quantum dots prepared from thiourea

• Published in: Talanta open Vol. 7; p. 100184
• Main Authors: Franco, Claudiomar R., Miranda-Andrades, Jarol R., Toloza, Carlos A.T., Larrudé, Dunieskys G., Maqueira-Espinosa, Luis, Aucelio, Ricardo Q., De Falco, Anna, Pedrozo-Peñafiel, Marlin J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2023; Elsevier
• Subjects: Carbon quantum dots; Flow injection analysis; Mercury; Photo-degradation; Thiomersal; Vaccines; Flow injection analysis; Vaccines; Photo-degradation; Carbon quantum dots; Thiomersal; Mercury
• ISSN: 2666-8319; 2666-8319
• DOI: 10.1016/j.talo.2023.100184

•Thiomersal was determined by FIA with a carbon nanomaterial luminescent probe.•Thiourea was used to get N, S-modified graphene quantum dots to interact with Hg2+.•Limit of detection of 25 µg L−1 was adequate for vaccine analysis.•High score in greenness indicates usefulness of the method for quality control.•Thiomersal photo-degradation was used to efficiently produce the detected Hg2+. Thiomersal is an organomercurial compound but, despite that, it is widely used in vaccines formulations to inactivate organisms and toxins and to prevent microbial growth during storage and use. In this work, thiomersal (along with traces of mercurial residues) was determined after photo-degradation (using UV and H2O2) to produce Hg2+ that was determined by flow injection analysis using luminescence probing with carbon quantum dots (prepared from citric acid and thiourea). Linear analytical response was observed in the concentration range of 25 to 900 µg L−1 and the method was efficiently applied to the determination of thiomersal in vaccines against hepatitis B and diphtheria-tetanus with recoveries ranging from 93 to 94%. [Display omitted]