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Physical & Chemical properties

Water solubility

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Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
9.11.2012 - 28.2.2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant OECD 105 study without significant deviations
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 830.7840 (Water Solubility)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 830.7860 (Water Solubility Generator Column Method)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of method:
column elution method
Key result
Water solubility:
< 1.67 other: ng/L
Temp.:
20 °C
pH:
>= 6.79 - <= 7.26
Remarks on result:
other: determined at two different flow rates (1.0 and 0.5 mL/min), 1.67 ng/L was the limit of quantification in this study.
Details on results:
Under the instrumental conditions presented, the mean measured reagent water solubility of Dechlorane Plus, based on the sum of the two test substance peaks, at 20 °C was less than the LOQ (1.67 ng/L) at both flow rates. Therefore, the overall mean measured water solubility of Dechlorane Plus was less than the LOQ (1.67 ng/L). Since the overall mean measured water solubility of Dechlorane Plus was less than the LOQ, a percent difference calculation, based on the means of the two flow rates, was not applicable. Representative chromatograms of solubility samples at flow rates of approximately 1.0 and 0.5 mL/min were considered. The measured pH of reagent water and an undiluted aqueous solubility sample collected at a flow rate of 1.0 mL/min were 6.79 and 7.26, respectively.

GC Operational Parameters

Instrument: Agilent Model 7890A Gas Chromatograph (GC) with Micro Electron Capture Detector (µECD)

Analytical Column: Restek Rtx®-5 (Cat. # 10223) (30 m * 0.25 mm, 0.25-µm film thickness)

Carrier Gas: Helium, nominal initial pressure = 22.374 psi (1 mL/min)

Injector: Temperature: 260 °C

Volume: 2.00 µL, splitless

Purge: 1.0 mL/min He at 0.5 min.

Total Flow: 3 mL/min

Oven Temperature Profile: Max temperature: 340 °C, Initial temperature: 260 °C, Initial hold time: 2.00 minutes

Ramp Rate 30 °C/minute to 330 °C, hold time 4 minutes and then 100 °C/minute to 260 °C, hold time 2 minutes

Run time: 11.033 minutes

Detector Temperature: 340 °C

Detector Gas Flow: Argon/methane makeup flow: 44.372 mL/min

Peak Retention Times: Peak 1: ~6.2 minutes, Peak 2: ~6.4 minutes

Conclusions:
Interpretation of results (migrated information): insoluble (< 0.1 mg/L)
The water solubility of Dechlorane Plus, based on the sum of the two test substance peaks, in reagent water at 20 ºC using the column elution method was determined to be less than the LOQ (1.67 ng/L) (N = 4).
Executive summary:

The water solubility of Dechlorane Plus in reagent water at 20 °C was determined using the column elution method. Column elution water was twice extracted with dichloromethane. The combined extract was evaporated to dryness, reconstituted with toluene, and analyzed using gas chromatography with micro electron capture detection (GC/µECD). The overall mean water solubility of Dechlorane Plus, based on the sum of the two test substance peaks, in reagent water at 20 °C, was determined to be less than the method limit of quantitation (LOQ = 1.67 ng/L, N = 4).

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
disregarded due to major methodological deficiencies
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: Purity and physical chemical properties of test substance not given. Hexane was used for preparing stock sultions and thus the results do overestimate true water solubility.
Qualifier:
no guideline followed
Principles of method if other than guideline:
Dilution in water by equilibration under slow stirring for 6 weeks. Extraction of water samples with 15% methylene chloride in hexane. Volume reduction of the extract in a steam bath and analysis by gas chromatography with electrone capture.
GLP compliance:
no
Type of method:
flask method
Water solubility:
>= 192 - <= 236 other: ng/l
Temp.:
22 °C
Remarks on result:
other: pH not measured, Isomer 1
Water solubility:
>= 502 - <= 685 other: ng/l
Temp.:
22 °C
Remarks on result:
other: pH not measured, Isomer 2
Details on results:
Two isomers with different solubility were seen, Isomer 1 with a mean solubility of 207 ng/l and Isomer 2 with a mean solubility of 572 ng/l.

Sample 1                     Isomer 1                     Isomer 2

211 ng/l                      623 ng/l

210 ng/l                      603 ng/l

236 ng/l                       685 ng/l

Sample 2                     193 ng/l                      507 ng/l

198 ng/l                      515 ng/l

192 ng/l                      502 ng/l

Mean                           207 ng/l                     572 ng/l

95% conf. range          13.6 ng/l                     63.3 ng/l

Conclusions:
Interpretation of results (migrated information): insoluble (< 0.1 mg/L)
Dechlorane Plus was practically insoluble in water with a solubility of 207 and 572 ng/l for isomers 1 and 2, respectively.
Executive summary:

The solubility of Dechlorane Plus was determined in water using radiolabeled substance. The stock solution was prepared in hexane. The stock solution was allowed to equilibrate with water for 6 weeks at 22 °C. Water samples were extracted with 15% methylene chloride in hexane, and Dechlorane Plus was analyzed using gas chromatography with electrone capture. The water solubility of Dechlorane Plus was determined at a mean of 207 ng/l for isomer 1 and at a mean of 572 ng/l for isomer 2. Dechlorane Plus was practically insoluble in water with a solubility below 0.1 mg/l.

Description of key information

The overall mean water solubility of Dechlorane Plus in reagent water at 20 °C, was determined to be less than the method limit of quantitation (LOQ = 1.67 ng/L, N = 4).

Key value for chemical safety assessment

Water solubility:
0.002 µg/L
at the temperature of:
20 °C

Additional information

The water solubility of Dechlorane Plus in reagent water at 20 °C was determined using the column elution method. Column elution water was twice extracted with dichloromethane. The combined extract was evaporated to dryness, reconstituted with toluene, and analyzed using gas chromatography with micro electron capture detection (GC/µECD). The overall mean water solubility of Dechlorane Plus, based on the sum of the two test substance peaks, in reagent water at 20 °C, was determined to be less than the method limit of quantitation (LOQ = 1.67 ng/L, N = 4).

In a previous study, water solubility had been determined using hexane as solubility enhancer and thus the results obtained in this supportive study appear to significantly overestimate water solubility and are disregarded.