Dear Tahereh,

The following publications cover the answer to your question:

1-Anal Bioanal Chem. 2006 Aug;385(7):1247-54. Epub 2006 May 17.

Rapid and quantitative extraction method for the determination of chlorophylls and carotenoids in olive oil by high-performance liquid chromatography.

Mateos R1, García-Mesa JA.

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Abstract

Colour is an organoleptic characteristic of virgin olive oil and an important attribute that affects the consumer perception of quality. Chlorophylls and carotenoids are the main pigments responsible for the colour of virgin olive oil. A simple analytical method for the quantitative determination of chlorophylls and carotenoids in virgin olive oils has been developed. The pigments were isolated from small samples of oil (1.0 g) by solid-phase extraction using diol-phase cartridges (diol-SPE), and the extract was analysed by reverse-phase HPLC with diode-array UV detection. Chromatographic peak resolution, reproducibility (coefficient of variation (C.V.) 98.4%) for each component were satisfactory. A comparative study of the proposed method was performed versus classical liquid-liquid extraction (LLE) with N,N'-dimethylformamide and solid-phase extraction using a C18 column (C18-SPE). While 96.4% of the pigments were recovered by LLE, only 51.3% were isolated by C18-SPE in comparison to diol-SPE. Likewise, a higher alteration of pigment composition was observed when such LLE and C18-SPE procedures were used. In this sense, a higher ratio of pheophytin in comparison to that isolated by the diol-SPE procedure was achieved with both extraction procedures, indicating a greater extent of the pheophytinization reaction. Therefore, quantification of pigments from virgin olive oil by diol-SPE followed by RP-HPLC was found to be rapid, simple, required only a small amount of sample, consumed only small amounts of organic solvents, and provided high recoveries, accuracy and precision.

http://www.ncbi.nlm.nih.gov/pubmed/16705414

2-J Agric Food Chem. 2014 Sep 24;62(38):9317-25. doi: 10.1021/jf503818k. Epub 2014 Sep 11.

Extraction of pigment information from near-UV vis absorption spectra of extra virgin olive oils.

Domenici V1, Ancora D, Cifelli M, Serani A, Veracini CA, Zandomeneghi M.

Author information

Abstract

This work reports a new approach to extract the maximum chemical information from the absorption spectrum of extra virgin olive oils (EVOOs) in the 390-720 nm spectral range, where "oil pigments" dominate the light absorption. Four most important pigments, i.e., two carotenoids (lutein and β-carotene) and two chlorophylls (pheophytin-a and pheophytin-b), are chosen as reference oil pigments, being present in all the reported analytical data regarding pigments of EVOOs. The method allows the quantification of the concentration values of these four pigments directly from the deconvolution of the measured absorption spectrum of EVOOs. Advantages and limits of the method and the reliability of the pigment family quantification are discussed. The main point of this work is the description of a fast and simple method to extract of such information in less than a minute, through the mathematical analysis of the UV-vis spectrum of untreated samples of oil.

http://www.ncbi.nlm.nih.gov/pubmed/25178056

3-https://books.google.ps/books?id=dgK9BAAAQBAJ&pg=PA233&lpg=PA233&dq=method+for+chlorophyll+liquid-liquid+extraction+from+olive+oil&source=bl&ots=Oyz81WnNSm&sig=fTWZN738OLKSOsmAT1ozTN3QcS0&hl=en&sa=X&ved=0ahUKEwjA5Oy31fXKAhVLChoKHZwlAIgQ6AEIPjAF#v=onepage&q=method%20for%20chlorophyll%20liquid-liquid%20extraction%20from%20olive%20oil&f=false

Hoping this will be helpful,

Rafik

I suggest you also read my article on its own quantification of chlorophylls, carotenoids and xanthophylls in olive oil.

Analytical Methods Pigments profile in monovarietal virgin olive oils from various Italian olive varieties.

FOOD CHEMISTRY 124:1119-1123

Pigments composition in monovarietal virgin olive oils from various sicilian olive varieties

FOOD CHEMISTRY 101:833-837