Photometric Determination of Novocaine with Preconcentration in Surfactant Micelles

• Published in: Journal of analytical chemistry (New York, N.Y.) N.Y.), 2022-08, Vol.77 (8), p.957-962
• Main Authors: Sokolova, T. A., Doronin, S. Yu
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Beer law; Chemical tests and reagents; Chemistry; Chemistry and Materials Science; Imines; Mathematical analysis; Micelles; Photometry; Procaine; Reagents; Schiff bases; Sodium dodecyl sulfate; Spectrophotometry; Sulfates; Surface active agents; Surfactants
• ISSN: 1061-9348; 1608-3199
• DOI: 10.1134/S1061934822080159

The work deals with the extraction and preconcentration of novocaine using mixed surfactants of nonionic (Triton X-114) and anionic (sodium dodecyl sulfate) types with the photometric registration of an analytical signal. The method is based on the condensation reaction of novocaine with p -dimethylaminobenzaldehyde (pH 2.5–3.5) and the subsequent micellar extraction of the colored analytical form, the Schiff base. For the effective extraction of this form, the parameters of micellar extraction (concentrations of reagents: с NaCl = 0.5–1 М, c Triton X-114 = 2 × 10 –3 –1 × 10 –2 M; conditions: centrifugation time 5 min at 3000 rpm) are optimized. The proposed method makes it possible to determine novocaine in the concentration range 38–4800 ng/mL (RSD ≤ 7%, limit of detection 19 ng/mL), which is several orders of magnitude lower than in the known spectrophotometric versions. The Bouguer–Lambert–Beer law is obeyed in the range 8 × 10 –7 –4 × 10 –5 M. The developed extraction-photometric method was tested in the determination of novocaine in 0.5% ampoule solutions for injection.