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EC number: 608-408-6 | CAS number: 29736-24-1
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Dissociation constant
Administrative data
Link to relevant study record(s)
- Endpoint:
- dissociation constant
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- september 2012 - november 2012
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: performance of the study was not inspected
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 112 (Dissociation Constants in Water)
- GLP compliance:
- yes
- Specific details on test material used for the study:
- Name: BLANCOLEN HP Disodiumhydroxy(sulfonato)acetate
Batch no.: 09102303
Designation in Test Facility: 12092101G - Dissociating properties:
- yes
- No.:
- #1
- Remarks on result:
- other: determination not possible
- Conclusions:
- A dissociation constant could not be determined according to the OECD 112 guideline.
- Executive summary:
The conductometric approach for the determination of the dissociation constant was chosen
on behalf of the properties of the test item. A titrimetric determination was not possible
as no point of equivalence could be observed neither by titration with acid nor with base. A
photometric determination was not possible as the UV/Vis spectrum did not change with
the pH.
The evaluation of the conductometric method showed a linear Kohlrausch correlation, indicating
that the test item is a strong electrolyte, but the calculated values, derived with
equation 2, showed a downward tendency. For a valid evaluation the calculated values
would show an asymptotic approximation with decreasing test item concentration (as it is
the case for e.g. acetic acid). The limit value determined in such a manner is then called
dissociation constant KD, its negative common logarithm is called pKD. For the test item,
such a limit value could not be determined. Therefore, the conductometric method yields
no reliable result, but confirms that the test item BLANCOLEN HP
Disodiumhydroxy(sulfonato)acetate is a strong electrolyte. With the conductometric
method it is not possible to distinguish if the sodium ions are dissociated either from the
carbonic acid or the sulfonic acid group. In conclusion it is not possible to determine a
dissociation constant following the OECD 112 guideline, neither using the titrimetric nor
the photometric nor the conductometric method.
As the test item is a sodium salt of a strong acid containing vincinal chemical groups with
high electronegativities it can be concluded that the test item would be virtually completely
ionised at environmentally relevant pH’s.
From the result of the titrimetric tests - no point of equivalence could be determined - it can
be further concluded that the anionic derivatives of the substance do not exhibit
noteworthy basic properties.
Reference
Main Test 1
The intercept of the linear fit of the Kohlrausch correlation represents the limit conductivity
of the test item (conductivity in unlimited dilution): 234.71 S*cm2*Mol-1.
Concentration. |
Molar Conductivity. |
Limit Conductivity |
Degree of Dissociation |
Mol/L |
S*cm2*Mol-1 |
S*cm2*Mol-1 |
α |
6.249E-04 |
225.62255 |
234.71 |
0.9612900 |
1.250E-03 |
221.62215 |
234.71 |
0.9442458 |
2.500E-03 |
215.62155 |
234.71 |
0.9186796 |
5.000E-03 |
207.82077 |
234.71 |
0.8854435 |
9.999E-03 |
197.61975 |
234.71 |
0.8419809 |
With the calculatedα,KDwas determined.
Degree of Dissociation |
Dissociation Constant |
- log (Dissociation Constant) |
α |
KD |
pKD |
0.9612900 |
0.014918 |
1.8262782 |
0.9442458 |
0.019988 |
1.6992407 |
0.9186796 |
0.025943 |
1.5859748 |
0.8854435 |
0.034216 |
1.4657714 |
0.8419809 |
0.044859 |
1.3481484 |
The mean of the measured values would be 1.59, standard deviation is 0.19 (RSD=11.9%), but the values showed a decreasing tendency with increasing concentration.
Main Test 2
The intercept of the linear fit of the Kohlrausch correlation represents the limit conductivity of the test item (conductivity in unlimited dilution): 233.92 S*cm2*Mol-1.
Concentration. |
Molar Conductivity. |
Limit Conductivity |
Degree of Dissociation |
Mol/L |
S*cm2*Mol-1 |
S*cm2*Mol-1 |
α |
6.249E-04 |
224.34243 |
233.92 |
0.9590727 |
1.250E-03 |
221.62215 |
233.92 |
0.9474434 |
2.500E-03 |
215.62155 |
233.92 |
0.9217906 |
5.000E-03 |
208.02079 |
233.92 |
0.8892971 |
9.999E-03 |
197.41973 |
233.92 |
0.8439771 |
With the calculatedα,KDwas determined
Degree of Dissociation |
Dissociation Constant |
- log (Dissociation Constant) |
α |
KD |
pKD |
0.9590727 |
0.014045 |
1.8524738 |
0.9474434 |
0.021347 |
1.6706541 |
0.9217906 |
0.027158 |
1.5660978 |
0.8892971 |
0.035716 |
1.4471389 |
0.8439771 |
0.045649 |
1.3405704 |
The mean of the measured values would be 1.58, standard deviation is 0.20 (RSD=12.6%), but the values showed a decreasing tendency with increasing concentration.
Description of key information
The test item behaves like a strong electrolyte (like a salt), which means that it dissociates quite completely.
It is not suspected to exhibit noteworthy basic properties.
Determination of a dissociation constant according to the OECD guideline 112 was not possible.
Key value for chemical safety assessment
Additional information
In conclusion it is not possible to determine a dissociation constant following the OECD 112 guideline, neither using the titrimetric nor the photometric nor the conductometric method.
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