Limits...
Identification and structural elucidation of ozonation transformation products of estrone.

Segura PA, Kaplan P, Yargeau V - Chem Cent J (2013)

Bottom Line: A control compare trend experiment consisting in the comparison of a control sample to several samples having been exposed to decreasing concentrations of O3(aq) indicated that 593 peaks could be associated with OTPs.After applying various filters to remove background noise, sample contaminants and signal spikes, this data set was reduced to 16 candidate peaks.Structures for these two compounds were proposed based on their MSn spectra.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Chemical Engineering, McGill University, 3610 University, Montreal, QC, H3A 2B2, Canada. viviane.yargeau@mcgill.ca.

ABSTRACT

Background: Quantitative methods for the analysis of contaminants of emerging concern (CECs) are abundant in the scientific literature. However, there are few reports on systematic methods of identification and structural identification of transformation products. For this reason, a new method based on high-resolution mass spectrometry and differential analysis was developed in order to facilitate and accelerate the process of identification and structural elucidation of transformation products CECs. This method was applied to the study of ozonation transformation products (OTPs) of the natural hormone estrone (E1).

Results: A control compare trend experiment consisting in the comparison of a control sample to several samples having been exposed to decreasing concentrations of O3(aq) indicated that 593 peaks could be associated with OTPs. After applying various filters to remove background noise, sample contaminants and signal spikes, this data set was reduced to 16 candidate peaks. By inspection of the shape of these peaks, only two compounds OTP-276 (m/z 275.12930) and OTP-318 (m/z 317.14008) were considered as good candidates for further study. Multi-stage tandem mass spectrometry (MSn) experiments of SPE extracts of the ozonated samples of E1 and of a deuterium-labeled analogue (E1-d4) showed that OTP-276 and OTP-318 had carboxylic acid and hydroxyl functional groups, as previously reported for OTPs of other hormones. Structures for these two compounds were proposed based on their MSn spectra.

Conclusion: These results indicate that the method proposed is a systematic and rapid approach to study transformation products of CECs.

No MeSH data available.


Related in: MedlinePlus

Molecular structure of estrone (E1) showing the standard C atom numbering and two possible structures for each of the identified OTPs. OTP-276B was not observed, while OTP-318B was 10 times less abundant than OTP-318A. Wavy bonds indicate that the exact stereochemistry is unknown.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3643888&req=5

Figure 1: Molecular structure of estrone (E1) showing the standard C atom numbering and two possible structures for each of the identified OTPs. OTP-276B was not observed, while OTP-318B was 10 times less abundant than OTP-318A. Wavy bonds indicate that the exact stereochemistry is unknown.

Mentions: In order to confirm the structure of the identified OTPs of E1, a deuterated E1 standard, estrone-2,4,16,16-d4 (99%) was bought from CDN isotopes (Point-Claire, QC). The E1-d4 standard used had two deuterium atoms (2H, but for simplicity D will be used instead) in the aromatic ring, in C-2 and C-4, and two geminal D atoms in C-16 (Figure 1). Semi-batch ozonation experiments, as described in section Preconcentration and purification, were performed with this standard to generate the same OTPs (but with different mass) in order to confirm the sites on the E1 molecule where reaction with O3 took place and propose structures of the MSn product ions of the identified OTPs of E1.


Identification and structural elucidation of ozonation transformation products of estrone.

Segura PA, Kaplan P, Yargeau V - Chem Cent J (2013)

Molecular structure of estrone (E1) showing the standard C atom numbering and two possible structures for each of the identified OTPs. OTP-276B was not observed, while OTP-318B was 10 times less abundant than OTP-318A. Wavy bonds indicate that the exact stereochemistry is unknown.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3643888&req=5

Figure 1: Molecular structure of estrone (E1) showing the standard C atom numbering and two possible structures for each of the identified OTPs. OTP-276B was not observed, while OTP-318B was 10 times less abundant than OTP-318A. Wavy bonds indicate that the exact stereochemistry is unknown.
Mentions: In order to confirm the structure of the identified OTPs of E1, a deuterated E1 standard, estrone-2,4,16,16-d4 (99%) was bought from CDN isotopes (Point-Claire, QC). The E1-d4 standard used had two deuterium atoms (2H, but for simplicity D will be used instead) in the aromatic ring, in C-2 and C-4, and two geminal D atoms in C-16 (Figure 1). Semi-batch ozonation experiments, as described in section Preconcentration and purification, were performed with this standard to generate the same OTPs (but with different mass) in order to confirm the sites on the E1 molecule where reaction with O3 took place and propose structures of the MSn product ions of the identified OTPs of E1.

Bottom Line: A control compare trend experiment consisting in the comparison of a control sample to several samples having been exposed to decreasing concentrations of O3(aq) indicated that 593 peaks could be associated with OTPs.After applying various filters to remove background noise, sample contaminants and signal spikes, this data set was reduced to 16 candidate peaks.Structures for these two compounds were proposed based on their MSn spectra.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Chemical Engineering, McGill University, 3610 University, Montreal, QC, H3A 2B2, Canada. viviane.yargeau@mcgill.ca.

ABSTRACT

Background: Quantitative methods for the analysis of contaminants of emerging concern (CECs) are abundant in the scientific literature. However, there are few reports on systematic methods of identification and structural identification of transformation products. For this reason, a new method based on high-resolution mass spectrometry and differential analysis was developed in order to facilitate and accelerate the process of identification and structural elucidation of transformation products CECs. This method was applied to the study of ozonation transformation products (OTPs) of the natural hormone estrone (E1).

Results: A control compare trend experiment consisting in the comparison of a control sample to several samples having been exposed to decreasing concentrations of O3(aq) indicated that 593 peaks could be associated with OTPs. After applying various filters to remove background noise, sample contaminants and signal spikes, this data set was reduced to 16 candidate peaks. By inspection of the shape of these peaks, only two compounds OTP-276 (m/z 275.12930) and OTP-318 (m/z 317.14008) were considered as good candidates for further study. Multi-stage tandem mass spectrometry (MSn) experiments of SPE extracts of the ozonated samples of E1 and of a deuterium-labeled analogue (E1-d4) showed that OTP-276 and OTP-318 had carboxylic acid and hydroxyl functional groups, as previously reported for OTPs of other hormones. Structures for these two compounds were proposed based on their MSn spectra.

Conclusion: These results indicate that the method proposed is a systematic and rapid approach to study transformation products of CECs.

No MeSH data available.


Related in: MedlinePlus