Figure 6.

Comparison of compositions of PFHxS isomers in a standard (STD) from Wellington, three PFHxS technical products (TP-1, Bidepharm; TP-2, CNW; TP-3, J&K Scientific), two PFOS industrial products containing PFHxS as impurity (IPP-1, Wuhan Haide Co. Ltd. (Wuhan, China); IPP-2, Qinhuangdao Bainaite Technology (Qinhuangdao, China) and Guangdong Rongxiang Technology (Dongguan, China)) and three water samples from different sources (W1, Haihe Rivers (n = 3); W2, Taihu Lake (n = 2); W3, drinking water from Tianjin city, China).