1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)pyridin-2(1H)-one, compound with 2-aminoethanol (1:1)

Monitoring data

Administrative data

Endpoint:

monitoring data

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Sampling and analytical method from the valid OECD 303A (IUCLID Section 5.2.2) study was establish STP Monitoring data for Octopirox. Therefore this study is reliable without restrictions.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

Sampling method and analytical from the STP Simulation study OECD 303A (see IUCLID Section 5.2.2) was used and the analytical method verified for the STP Measurements

GLP compliance:

no

Remarks:

Sampling and analytical measurements in sewage influent and activated sludge used the methods described in the GLP study OECD 303A described in IUCLID Section 5.2.2 but GLP was not fully implemented for cost reasons.

Type of measurement:

other: concentrations in two municipals STPs

Media:

other: Determination of concentrations in STP Sewage influent and in activated sludge

Test material

Test material information

Constituent 1

Reference substance name:

1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)pyridin-2(1H)-one, compound with 2-aminoethanol (1:1)

EC Number:

272-574-2

EC Name:

1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)pyridin-2(1H)-one, compound with 2-aminoethanol (1:1)

Cas Number:

68890-66-4

Molecular formula:

C14H23NO2.C2H7NO

IUPAC Name:

1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)pyridin-2(1H)-one, compound with 2-aminoethanol (1:1)

Constituent 2

Reference substance name:

Octopriox

IUPAC Name:

Octopriox

Details on test material:

as specified before

Study design

Details on sampling:

A series of samples was taken. Samples from Hildesheim were taken on Monday, 2006-01-30 – Wednesday, 2006-02-01 and Friday, 2006-02-03. Samples from Hannover were taken on Thursday, 2006-02-09 and Friday 2006-02-10. Influent samples as well as activated sludge samples were grab samples. Influent samples were taken at the end of the primary settler. Sludge samples were taken from the activated sludge tank .
Sample preparation was carried out as described in the analytical report „Analytical Method for Determination of Octopirox in Activated Sludge and Effluent for a Simulation Test – Aerobic Sewage Treatment” (2006-01-24) see IUCLID Section 5.2.2. To 25 mL of sewage influent (without any further pre-treatment) 1.25 mL TiCl3 solution were added and mixed. After 10 min 5 mL of the solution were cleaned up over C18-SPE cartridges. Elution was carried out with 5 mL of Methanol and the eluate used for LC MS/MS analysis. 10 mL activated sewage sludge were centrifuged for 10 min at 3000 rpm. The supernatant was rejected. 0.5 mL TiCl3 solution were added and the samples were filled up to 10 mL with HPLC water. The extraction was carried out on a gyratory shaker for 1 h at 300 rpm. Afterwards the samples were centrifuged for 10 min at 3000 rpm. The supernatant was diluted with HPLC water if necessary and analysed. Results were calculated related to the sludge dry weight.

Results and discussion

Details on results:

The analysis of Octopirox from two series of samples confirmed the presence of Octopirox in both sewage influent and sewage sludge. The concentrations measured for two sewage treatment plants were different. Whereas the sewage influent of STP Hannover had lower concentrations of Octopirox, the concentration in activated sewage sludge was higher compared to STP Hildesheim.

Octopirox concentration in raw sewage influent of the municipal sewage treatment plant in Hildesheim was in a range of 0.92 – 1.35 µg/l. The concentration of Octopirox in activated sewage sludge was 3.40 – 4.06 mg/kg dw.

For the municipal sewage treatment plant in Hannover Octopirox concentration in the raw sewage influent was in a range of 0.30 – 0.55 µg/L and 4.66 – 5.30 mg/kg dw in activated sewage sludge.

Recovery rates of the fortification tests confirm the robustness of the analytical method for the determination of Octopirox in raw sewage influent and activated sewage sludge of municipal sewage treatment plants.

Applicant's summary and conclusion

Conclusions:

The measured Sewage influent concentrations measured in two Sewage Treatment Plants (Hanover and Hildesheim, Germany) are by a factor of more than 5 lower than estimated by the Exposure Modelling Program EUSES 2.1. The concentrations of Octopirox in the activated Sludge of the STPs are by a factor of more than 6 lower than estimated by EUSES 2.1. One possible explantion could be that Octopirox may have a lower use rate in the area where these STPs are located.

Executive summary:

The analysis of Octopirox from two series of samples confirmed the presence of Octopirox in both sewage influent and sewage sludge. The concentrations measured for two sewage treatment plants were different. Whereas the sewage influent of STP Hannover had lower concentrations of Octopirox, the concentration in activated sewage sludge was higher compared to STP Hildesheim. Octopirox concentration in raw sewage influent of the municipal sewage treatment plant in Hildesheim was in a range of 0.92 – 1.35 µg/l. The concentration of Octopirox in activated sewage sludge was 3.40 – 4.06 mg/kg dw. For the municipal sewage treatment plant in Hannover Octopirox concentration in the raw sewage influent was in a range of 0.30 – 0.55 µg/L and 4.66 – 5.30 mg/kg dw in activated sewage sludge. Recovery rates of the fortification tests confirm the robustness of the analytical method for the determination of Octopirox in raw sewage influent and activated sewage sludge of municipal sewage treatment plants.