Intralaboratory validation, comparison and application of HPLC-UV-DAD methods for simultaneous determination of benzalkonium chloride, chlorexidine digluconate and triclosan

Abstract

Benzalkonium chloride (BAC), chlorhexidine digluconate (CD) and triclosan (TR) are widely used antimicrobial agents since they are antiseptics and disinfectants depending on the used concentration. The objective of this work was the development of methodology for the fast and simultaneous determination of CD, TR and the BAC homologues (C12, C14 and C 16) using HPLC-UV-DAD. Two isocratic reverse-phase systems were optimized: system C8 - column SB-C8 (250 × 4.6 mm; 5 μm) using a mobile phase composed of ACN and H3PO4/NaH2PO 4 buffer 0.03 mol L-1, pH 2.0 (80:20, v/v); 2.0 mL min-1 and system CN - column SB-CN (150 × 4.6 mm; 5 μm) using a mobile phase composed of ACN and HOAc/NaOAc buffer 0.1 mol L -1, pH 5.0 (70:30, v/v); 2.0 mL min-1. In both systems the total analysis time was lower than 6 min, leading to high throughput and low production of solvent rejects. Linear ranges with two magnitude orders were found for the fve substances in both systems. The sensitivity of system C8 for the fve substances was around 20% greater than that of system CN. Both chromatographic methods showed overall precisions better than 4.5%, good resolutions (R < 1.8) and high recoveries (96 to 103%). The limits of quantifcation were adequate for the determination of the fve compounds in commercial products. The analysis of several commercial products showed a good agreement between both chromatographic methods. Good agreement among measured concentrations and labeled values was also observed. © 2011 Sociedade Brasileira de Química.