## 4 Discussion  
[PERSON] and [PERSON] [32] developed a method for integrated determinations of PAHs, PCBs, and organochlorine pesticides in fish livers using SPE columns with alumina. The two fractions obtained are eluted with n-hexane/dichloromethane. The first extract is used for determinations of PCBs, HCB, and DDTs, while the second is used for determinations of PAHs and HCHs. The authors report that extraction in a Soxhlet extractor permitted obtaining greater analyte recovery than did saponification in an NaOH solution. The disadvantageous effects of saponification were particularly notable for chlorinated hydrocarbons, especially since the complete decomposition of HCH and pp'-DDT (dichlororethane) occurred, rendering their analysis impossible. A similar method of extract  
Figure 4: Comparison of PHA contents in dried fruits analyzed with methods 2, 3, and 4. (**a**)—apricot, (**b**)—pear, (**c**)—apple; 2—determined with the specific method for PAHs; 3—determined according to the methods of [PERSON] and [PERSON] [32]; 4—determined according to the methods of [PERSON] et al. [33]. fractionation is proposed by [PERSON] et al. [33]. Alumina and silica gel are used as the adsorbents. Individual fractions are eluted with n-pentane and a n-pentane and dichloromethane mixture. The method is used to determine PAHs and organochlorine compounds in mussels, cod liver oil, and benthic sediments. These authors, similarly to [PERSON] and [PERSON] [32], also pointed out that the procedure of analyte extraction based on saponification in an ethanolic KOH solution requires additional stages of extract cleanup due to saponification residues and results in a lower recovery values than the procedure using Soxhlet extraction. Two fractions are obtained: one containing aliphatic hydrocarbons and PCBs, and one with PAHs. Compared to the method described by [PERSON] and [PERSON] [32], this procedure requires using more solvents. Simultaneous determinations of PAHs and PCBs in foodstuffs poses a high degree of difficulty due to the complexity of food matrices and the presence of organochlorine compounds in very low concentrations, with relatively high PAH contents. The matrix contains all the components in the sample, not just the analytes of interest. Sample extracts with high levels of organic matter, including lipids, organic acids, etc., contain substances that are co-extracted and deposited on the chromatographic column, reducing separation efficiency and interfering with the analytical method [35; 36]. The matrix effect is influenced by the presence of interferences that coelute with analytes present in low concentrations [37; 38]. Therefore, interference from the matrix may affect the accuracy of the analytical method. Their elimination before the final determination stage is crucial for the quality of the analysis. Therefore, it is important to use procedures to minimize the matrix effects, e.g., internal standards and the implementation of new methods of purifying the extracts. The analytical procedure that consists of the selective isolation of analytes, cleanup, and extract fractionation and quantification must also be adapted to the physicochemical properties of the compounds tested. In most studies, the contents of PAHs and organochlorine compounds in fruits are analyzed with separate methods specific to each group [20; 21; 39]. Relatively few researchers are currently working on developing an integrated method to analyze all of these compounds (Table 5). The methods proposed differ significantly in terms of complexity, the numbers of stages, and the sorbents used. Some commonly applied methods use, for example, Soxhlet apparatuses and sorbents that have been in use for many years [40], while others use modern sorbents and apparatuses [41; 42; 43]. Among the modern methods, zirconium oxide-based sorbents, in particular, are used instead of PSA/C18 in QuEChenERS cleanup, and they ensure a lower background and higher recovery of some compounds [44; 45].