Differential global profiling as a new analytical strategy for revealing micropollutant treatment by-products: Application to ethinylestradiol and chlorination water treatment

Transformation Products of Emerging Contaminants upon Reaction with Conventional Water Disinfection Oxidants

“…A good example of the advantages of the use of metabolomics software is presented by Gervais et al [30] who studied the reaction of 17-a-ethinylestradiol (EE2) with chlorine and compared the metabolomics approach to the classical one. As a result, six new TPs were discovered, which could not be easily detected by the classical approach.…”

“…In the case of estrogenic steroids, the main pathway is an electrophilic attack of chlorine or bromide on ortho carbons in the phenolic ring [30,45,[59][60][61]. For E1, in a second step, the dichlorinated TP undergoes an oxidative chlorination at position 10, leading to a trichlorinated product 2,4,10-trichloro-1,4-estradiene-3,17-dione, and a further substitution at the same position by a hydroxy group [45].…”

“…For E1, in a second step, the dichlorinated TP undergoes an oxidative chlorination at position 10, leading to a trichlorinated product 2,4,10-trichloro-1,4-estradiene-3,17-dione, and a further substitution at the same position by a hydroxy group [45]. For EE2, eight hydroxylated and halogenated forms were detected, but some uncertainties remain concerning the exact positions of the hydroxy and halogen groups [30]. Finally, in the case of E2, besides three chlorinated products (2,4-dichloro-E2, monochloro-E1 and 2,4-dichloro-E1), four TPs formed by ring cleavage through 9-10 and 16-17 bonds were identified [59].…”

A non-target approach to identify disinfection byproducts of structurally similar sulfonamide antibiotics

“…First, not enough data is available on the DBPs formed from structurally similar chemicals to directly assess whether structurally similar chemicals react with free chlorine in analogous ways. Second, studies aimed at elucidating DBPs of anthropogenic chemicals rarely employ emerging analytical techniques that can comprehensively identify candidate DBPs in a nontargeted way (Gervais et al, 2011;Gulde et al, 2016;Helbling et al, 2010;Negreira et al, 2015). As a result, the full spectrum of DBPs that may form in reactions with free chlorine is mostly unknown which limits our understanding of possible free chlorination reactions.…”

Identification and structural elucidation of ozonation transformation products of estrone

“…This experiment consists in the comparison to a control of several samples in which a variable has been modified, in this case the concentration of O 3 . A similar approach using differential global profiling was reported previously, however it only compares two sets of samples: a control and a treated group [20]. The advantage of the control compare trend experiment for the identification of OTPs is the possibility of monitoring the signal of the studied CEC and its OTPs as a function of a variable known to affect the formation of OTPs.…”