title: Voltammetric determination of N-nitrosoderivatives of atenolol and propranolol in simulated gastric juice.
abstract: A highly sensitive and simple voltammetric method is proposed for the determination of N-nitrosoatenolol (NA) and N-nitrosopropranolol (NP) in simulated gastric juice. The method is based on measuring the differential-pulse polarographic peak produced by NA and NP in Britton-Robinson buffers of pH 3 and 4 for NA and NP, respectively. Both compounds yielded diffusion-controlled current with diffusion-current constants of 7.23 +/- 0.03 and 9.46 +/- 0.06 for NA and NP, respectively. The current-concentration plots were rectilinear over the range 0.16-9.6 micrograms ml-1 with minimum detectability (S/N = 2) of 0.015 microgram ml-1 (5 x 10(-8) M) for NA; for NP the range was 0.08-8.0 micrograms ml-1 with minimum detectability (S/N = 2) of 0.009 microgram ml-1 (3 x 10(-8) M). The proposed method was successfully applied to study the possible in vivo production of the nitroso-derivatives under the standard nitrosation reaction conditions recommended by WHO. The method is characterized by simplicity and higher sensitivity as compared with the reported HPLC method.
authors.affiliation: Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia.
authors.forename: F
authors.initials: F
authors.lastname: Belal
authors.forename: O A
authors.initials: OA
authors.lastname: al-Deeb
authors.forename: A A
authors.initials: AA
authors.lastname: al-Majed
authors.forename: E A
authors.initials: EA
authors.lastname: Gad-Kariem
mesh_terms: D001262:Atenolol / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D006863:Hydrogen-Ion Concentration; D009602:Nitrosamines / Q000032:analysis* / Q000378:metabolism; D011048:Polarography; D011433:Propranolol / Q000031:analogs & derivatives* / Q000032:analysis
chemical_list: D009602:Nitrosamines; D001262:Atenolol; C037601:N-nitrosopropranolol; D011433:Propranolol