Direct olive oil anisidine value determination by flow injection

A flow injection (FI) spectrophotometric method for the determination of olive oil anisidine value (AV) is presented. A 40-1 aliquot of 10% (w/v) olive oil samples in 2-propanol are injected in a p-anisidine in 2-propanot/acetic acid stream. The reagents are premixed in the FI system using a two-line manifold. Detection is achieved by monitoring absorbance continuously at 350 urn. The proposed FI method achieves a high analysis rate (110 samples/h), minimizes solvent consumption (2 ml 2-propanol and 0.4 ml acetic acid per analysis) and compares well with the manual spectrophotometric method (relative difference 0.5-6.8% for the analysis of 25 olive oil samples). Precision was found to be better than 1% relative standard deviation (R.S.D.; n = 7). The linear range was 6-85 AV and is suitable for analysis of abused olive oils. (C) 2001 Elsevier Science B.V. All rights reserved.