Determination of thimerosal in pharmaceutical industry effluents by High Performance Liquid Chromatographic with post-column derivatization coupled to Atomic Fluorescence Spectrometry

ACOSTA G; ALESSO M; SPISSO A; TALIO C; FERNÁNDEZ L; PACHECO P; GIL R

Congreso; 3° Reunion Internacional de Ciencias Farmaceuticas; 2014

Thimerosal (THM) has been employed as antimicrobial agent in a variety of products including topicalanti-septic solutions, cosmetics, cleaning solutions for contact lenses, vaccines and other injectablebiological products. THM is decomposed by oxidation to 2,2´-dithiosalicylic acid, thiosalicylic acid,EtHg and elemental mercury. Due to THM is now considered as a potential emerging contaminant. Theaim of this work was to develop a hyphenated methods for simultaneous determination of THM, EtHg(II)and Hg(II) in pharmaceutical industry effluents.Separations were performed with a Series 200, Perkin-Elmer binary pump. The column used was ZorbaxSB-Aq C18-RP Agilent Technologies. Mercury fluorescence measurements were carried out with anatomic fluorescence spectrometry (AFS), AI 3300, Aurora Instruments. A standard solution of THM wasobtained dissolving 1000 mg L-1 of sodium ethylmercurythiosalicyclate from Sigma Aldrich. A 10 mg L−1standard solution of inorganic mercury was obtained from Perkin-Elmer. A 1000 mg L−1 standardsolution of ethylmercury chloride in water were obtained from Fluka. All other reagents and solventswere of analytical grade.Mercury cold vapor formation from THM and EtHg in the mobile phase was evaluated in a univariateapproach. THM eluted quickly without decomposition using formic acid 0.5% mobile phase, whilst bothHg(II) and EtHg(II) did not elute even at elution times as long as 30 min. Hg(II) and EtHg(II) specieseluted well, however, in a mobile phase composed by 0.5% of formic acid and 0.1% of β-mercaptoethanol (β-ME). Under optimized condition THM eluted in 0.5% formic acid with retention timeof 3.9 min, and EtHg(II) and Hg eluted at 8.3 and 12.5 min respectively after switching to a mobile phasewith 0.5% formic acid and 0.1% β-ME.This procedure methodology is fast and simple becoming adequate for screening procedures for thedetermination of Hg(II), EtHg(II), and thimerosal in pharmaceutic industrial effluents.