| A sensitive and reliable method for determination of trace levels of PFCs in human urine, hair and nails samples was developed using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) with stable isotope dilution and appropriate preparation technique. The human urine was purified and extracted by the Oasis weak anion exchange (WAX) solid-phase extraction (SPE) after adding 1mL 2% formic acid in methanol. The extracts were concentrated to 200μL. The recovery test of the method was conducted by analyzing human urine spiked at three different concentrations (20pg/mL, 100pg/mL, 500pg/mL). The average recovery range of 12 PFCs in three spike levels were 80%～116%. The RSD (n= 6) was between 2.1% and 21%. The LOD was from 0.44 to 3.47pg/mL, and the LOQ was from 1.03 to 11.06pg/mL. Acetonitrile (ACN) extracting combined with SPE was developed for human hair samples. The average recoveries of 8 analytes were between 88% and 114% in three spike levels (5ng/g, 10ng/g, 50ng/g). The RSD was between 2.8% and 18%. The LOD and LOQ were 6.0 - 35pg/g and 21 -78 pg/g, respectively. For nails sample, the alkaline digestion was selected for preparation, then the extracts was cleanup using SPE. Satisfying average matrix recoveries (91%-124%) for 8 target compounds in different spiked levels (3ng/g, 10ng/g, 30ng/g) were obtained. The RSD were between 1.9% and 11%. The LOD of method varied from 5.0 to 17pg/g, the LOQ was from 16 to 55pg/g.Four human matrices including urine, hair, nails and serum from Shanxi Province were analyzed. The relationships among the concentrations of PFCs of four different human matrices were calculated. PFOS, PFOA, and PFHxS were detected in urine, hair, nails and serum. The profiles of relative concentrations of PFOS, PFOA and PFHxS were compared among different human matrices. The percentage composition in urine was unique, with about 68% contribution from PFHxS and around 30% from PFOS. Among other human matrices, the dominant contribution was from PFOS (>50%). The concentration of PFOS in human hair was correlated to the level of PFOS in human serum. There was significant correlation between human nails and serum PFOA levels, a significant correlation was also observed between the human nails and serum PFOS levels. These results indicated that human urine, hair and nails could be the alternative matrices for PFOS or PFOA exposure in human.The 141 human whole blood samples collected from four cities around Bohai Sea in China including Qinhuangdao, Tangshan, Weihai, and Zouping were analyzed for PFCs. PFOS was found to be the dominant PFCs in human blood. The highest median concentration of total PFCs was found in whole blood samples from Tangshan (14.01ng/mL). The median concentration of total PFCs in samples from Zouping (7.28ng/mL) was the lowest, but the median concentration of PFOA (3.26ng/mL) was the highest among four cities and the percentage proportion of PFOA (45%) was higher than that of PFOS (30%). The concentrations of PFOS and PFHxS in male were higher than that in female (p <0.01). No statistically significant difference in PFCs blood concentrations between two age groups (p >0.05). Based on the different profiles of PFCs between Zouping and other three coastal cities, it was suggested that there might be different human exposure sources and pathways of PFCs around Bohai Sea. The significant relationship (p <0.01) was found between PFHxS and PFOS, PFNA was also correlated to PFOS (p <0.01). |
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