title: Specific spectrophotometric method with trifluoroacetic acid for the determination of selenium(IV) in selenitetriglycerides.
abstract: The role of selenium as an antioxidant and anticancer agent is very well documented in the literature. Selenium compound showing the highest activity as a free radicals scavenger and as an anticancer agent should contain selenium at +4 oxidation level. The synthesis of selenitetriglycerides (named selol) was carried out in the Department of Drug Analysis at Warsaw Medical University (Polish Patent 1999). Selenitetriglycerides showed a dimeric structure. In a single dose toxicity studies performed in rats, LD50 was 100 mg Se kg(-1) after oral administration of selol. The subcutaneous and intraperitoneal administration of selol showed extremely low toxicity. The aim of this work was to develop a new specific method for the determination of Se(IV) in selol. We stated that selenitetriglycerides react quantitatively with trifluoroacetic acid (TFA) in dichloromethane giving a red-coloured conjugate. However, recorded spectrum showed the maximum absorption in the wavelength 380 nm. The optimal conditions of the reaction were established, namely temperature 35 degrees C and reaction time 35 min. The reaction was proved to be specific because neither selenites nor other selol constituents react with TFA. The constructed calibration curve obeyed the Lambert-Beer law in the range of 0.1-7.4 mg ml(-1). Molar absorption coefficient is epsilon =9.46 x 10(3) l mol(-1) cm(-1) and epsilon =2.36 x 10(5) l mol(-1) cm(-1) calculated for selenium and selenitetriglyceride dimer (m.w. 1972.72), respectively. Obtained results for selenium determination were confirmed by AAS method. The developed method showed specificity and high sensitivity.
authors.affiliation: Department of Drugs Analysis, Warsaw Medical University, 1 Banacha Str., 02-097 Warsaw, Poland. suchoc@amwaw.edu.pl
authors.forename: P
authors.initials: P
authors.lastname: Suchocki
authors.forename: D
authors.initials: D
authors.lastname: Jakoniuk
authors.forename: B A
authors.initials: BA
authors.lastname: Fitak
mesh_terms: D012643:Selenium / Q000032:analysis* / Q000737:chemistry; D018038:Sodium Selenite / Q000032:analysis* / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013678:Technology, Pharmaceutical / Q000379:methods*; D014269:Trifluoroacetic Acid / Q000032:analysis* / Q000737:chemistry; D014280:Triglycerides / Q000032:analysis* / Q000737:chemistry
chemical_list: D014280:Triglycerides; D014269:Trifluoroacetic Acid; D012643:Selenium; D018038:Sodium Selenite