Determination of TOTOX value in palm oleins using a FI-potentiometric analyzer

A flow injection analyzer for the determination of total oxidation value (TOTOX) in palm oleins was developed based on the sequential determination of peroxide value (PV) and anisidine value (AV) using a common triiodide (I-3(-)) potentiometric detector. The PV and AV parameters were sequentially determined by manipulating a switching valve. The mixing of the oil and reagents was effective by applying a short vortex (30 s). The TOTOX value is obtained from the potentiometric readings of PV and AV (TOTOX = 2PV + AV). Using palm olein as standard, the method gives TOTOX value that is linear over 1.7-79.0 with a detection limit of 1.64. The sampling frequency is about 60 h(-1). Twenty aged and thermally stressed palm olein samples were analyzed and good correlations (r(2) = 0.9852) were found between the proposed FIA and the official methods. (C) 2008 Elsevier Ltd. All rights reserved.