# Assessment of Bioactive Surfactant Levels in Selected Cereal Products
## 3 Results
### Analysis of Real Samples  
In order to improve the transparency of the data and provide a better demonstration of the results, the analyzed food items were divided into three subgroups. Thus, three separate tables were prepared: Table 2--flours and brans; Table 3--noodles, rices, and goats; Table 4--bread and rolls (baked cereal-based products). The presence of 10 PFASs was examined in this study. Only five of them were found in concentrations above LOQ, namely PFBA, PFPeA, PFHxA, PFOA, and PFOS. PFOA was indicated as the most frequently detected perfluoroalkyl substance during the experiment. PFOA was detected (at a level above LOQ) in 65.2% of samples, followed by PFBA (39.3%), PFHxA (21.3%), PFOS (14.6%), and PFPeA (11.2%). In the group of flours and brans, only PFBA was found at levels above LOQ at the concentration range of 0.88 to 202.85 ng/g for wheat flour and wheat brans, respectively. The presence of four of the five detected compounds (PFBA, PFPeA, PFOA,and PFOS) was confirmed in the subgroup of noodles, rices, and groats (PFHxA levels were below LOQ for all samples). In the case of baked cereal products, PFOA and PFHxA were found at detectable levels. PFOA was identified in all the analyzed samples, but PFHxA was detected only in bread samples. In the group of PFCAs, PFBA was the compound with the highest individual measured concentrations, which reached the level of 202.85 ng/g ww for wheat bran. The highest mean concentrations of PFBA were found in wheat bran, rye bran, and rye flour and were estimated to be 119.68, 63.31, and 20.05 ng/g, respectively. Despite the fact that PFOA was the most abundant compound, its concentration was not higher than 0.430 ng/g. PFPeA and PFHxA were found more rarely. PFHxA was detected only in bread samples within the concentration range of <LOQ-0.44 ng/g, while PFPeA was found in white rice and millet groats at concentrations not exceeding 0.34 ng/g. In the family of PFSAs, only PFOS was detected at levels above the LOQ value. This compound was detected in both types of noodles, white rice, and millet groats. Its concentrations ranged from <LOQ to 8.39 ng/g for millet groats. The major contributor to the total PFCA concentration in the investigated cereal-based foods was PFBA (99.1%); the proportions of the other compounds did not exceed 0.7% (PFOA). The average concentrations of the sum of individual PFASs are displayed in Figure 1. The highest average concentrations were observed for wheat and rye bran; these concentrations resulted only from the presence of PFBA in the analyzed samples. For samples for which more than one PFAS was determined at levels above LOQ, the highest average concentrations were calculated for plain noodles (3.17 ng/g), durum noodles (5.60 ng/g), and millet groats (2.07 ng/g). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**PFAS** & **a** & **R2** & **LOD** & **LOQ** & **Recovery [\%]** \\  & & & **[ng/g]** & **[ng/g]** & **[ng/g]** \\ \hline PFBA & 3.552 & 0.998 & 0.018 & 0.061 & 87 \\ PFPeA & 4.026 & 0.999 & 0.019 & 0.064 & 89 \\ PFHxA & 2.715 & 0.999 & 0.022 & 0.072 & 93 \\ PFHpA & 1.662 & 0.999 & 0.014 & 0.047 & 97 \\ PFOA & 2.506 & 0.999 & 0.016 & 0.052 & 102 \\ PFNA & 1.626 & 0.999 & 0.015 & 0.050 & 94 \\ PFDA & 0.965 & 0.999 & 0.018 & 0.061 & 89 \\ PFBS & 7.709 & 0.999 & 0.021 & 0.070 & 99 \\ PFHxS & 7.786 & 0.997 & 0.013 & 0.043 & 96 \\ PFOS & 2.940 & 0.999 & 0.017 & 0.057 & 94 \\ \hline \hline \end{tabular} Abbreviations: a—calibration slope; R2—coefficients of determination; LOD—limit of detection; LOQ—limit of quantification.  
\end{table} 
Table 1: Data of the quantification of determined PFAS.