In analytical methods for analysis of PAHin foods several parameters like as extraction, clean up, detection, quantificationand column size for determination PAH should be considered.
For the determination of PAHs in dairy products few works have beenreported by high-performance liquid chromatography (HPLC) coupled tofluorescence (FLD) (Kishikawa et al. 2003; Santonicola et al. 2017 ;Londoño et al. 2013), HPLC–UV (38?40, 62, 66, 67, 78, 80, 86) and gas chromatography with mass spectrometry (GC–MS) ( Sanagi etal, 2013; Aguinaga et al. 2007; Lee et al. 2015)or GC–MS/MS(28, 31, 38, 79) (depending on the nature of the sample and its volatility) (Liet al. 2003).The procedure of sample preparation such as soxhlet, solid-phase,and liquid-liquid extraction, saponification with KOH–methanol solution 17,is very difficult and time-consuming and need to use high solvents.
In solidsamples, PAH can be extracted by Soxhlet method (34, 36, 50, 81) and manyorganic solvents can be used. This extraction method although is efficient formany samples, it needs large volumes of solvents (300 mL), and istime-consuming (6?24 h).Therefore cannot extract PAH compounds exactly. Analkaline saponification with KOH–methanol solution or NaOH ethanol used forliberating of PAHs bound to Compounds or to eliminate some lipid components butSome PAHs may be under strongly alkaline conditions degraded and some BaP bypartial portioning to the alcoholic phase may be lost. For these reasons, developedsolvent extraction methods have been established, including ultrasound-assistedextraction (USE) (26, 40, 39, 42–44, 66, 71–73, 77, 83, 87), microwave-assistedextraction (MAE) 51, pressurized-liquid extraction (PLE) 28, 38, 50, 60, 63, 64, headspace-solid-phase microextraction (HS-SPME) (Guillénand Sopelana, 2005) anddirect-immersion- solid-phasemicroextraction (DI-SPME) (Doong et al. 2005) (Table 2). On the otherhand, usually during analysis of target samples, many other ingredients andcomponents are co-extracted.
In plants, natural pigments and essential oils and in animaltissue, lipids arethe most components which analyzing together with the target sample. Thereforethe validation of method is very important to achieve best results of PAH in the samples. Theprocedures used for extraction of PAHs from food critically depend on the natureof the sample conditions.
W?grzyn etal. modified analytical method of PAH in milk powder and cottage cheesesamples by using size exclusion chromatography (SEC) for sample preparation andRP-HPLC with florescence detection. The results showed that SEC is suitablemethod for isolation PAH in different foods especially dairy products.
Because ofthe three clean-up procedures investigated in this study, only SEC enables toone-step clean-up. On the other hand, it is fast, sensitive and selectivemethod for determination PAH.Naccari et al.(2011) studied on PAHs concentration in heat-treated milk samples. Quantitative determination of PAHs was performed by HPLC using afluorescence detector and offered agood selectivity and separation of the 16 PAHs analyzed.
All PAHs were detectedby fluorescence, using specific emission and excitation wavelengths for eachcompound, leading to good detection limits. Except for Acenaphtlylene ACEN and Indeno(1,2,3-cd)pyreneI(c,d)P since these were not fluorescent. Likewise they found thatamong ionization techniques for the analysis of PAHs in nonvolatilematrices, APCI (atmospheric pressure chemical ionization) coupled with highperformance liquid chromatography is undoubtedly the more suitable for theanalysis of these molecules (Anacleto,Ramaley, Benoit, Boyd, & Quilliam, 1995).Aguinaga, et al (2007) investigated 16 PAH in milk and related products using solid-phasemicroextraction by gas chromatography–mass spectrometry. They foundthat involvement SPME-GC–MS is a suitable techniquefor the purpose of the 16 PAHs in milk samples and related products. Byselecting SPME method for PAH analysis in milk and dairy products, timeconsuming for sample preparation was reduced and no need to use of organicsolvent and clean-up steps.