2-methylbutane

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Up to 2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Source is a published handbook, no data on GLP/guideline compliance/method. Acceptable with restriction as handbook is peer reviewed and considered a reliable source.

Principles of method if other than guideline:

The use of secondary sources of data is acceptable when they are based on a critical evaluation of peer-reviewed data and a consequent selection of a reliable and representative value for the property under investigation. The introduction to the CRC Handbook of Chemistry and Physics states that data for physical constants have been taken from many sources, including both compilations and the primary literature. Where conflicts were found, the value deemed most reliable was chosen. Therefore, although the method used is not known, the values presented here are acceptable as they are from a reliable secondary source of phys chem. data.

GLP compliance:

not specified

Remarks:

Not reported

Type of method:

other: Not reported

Key result

Water solubility:

0.049 g/L

Temp.:

25 °C

pH:

7

Remarks on result:

other: pH not stated, therefore assumed standard

Details on results:

Not reported

Conclusions:

Interpretation of results: slightly soluble (0.1-100 mg/L)

The water solubility of 2-methylbutane was reported as 0.0485 g/l at 25°C (48.5 mg/l).

Executive summary:

There is no available information on the methods used to determine the value for this endpoint. However, this information is taken from the CRC Handbook which is considered to be a reliable peer reviewed handbook and suitable for use as the key study for this endpoint. The water solubility of 2-methylbutane was reported as 0.0485 g/l at 25°C (48.5 mg/l).

Reference 2

Endpoint:

water solubility

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

Up to 1966

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Predates implementation of GLP and development of standard guidelines but otherwise acceptable for assessment

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

Guideline:

other: Unknown if guideline was used for this study

Principles of method if other than guideline:

n-Pentane at one atmosphere was added to a glass equilibraton bottle filled with distilled water by displacing water until the volume of the aqueous phase was 3/4 of the volume of the bottle. The gas was maintained over the water. A rubber balloon in the line from the gas cylinder to the bottle served as a resevoir and was remained in-line until the aqueous phase was sampled. The 3/4 full bottle was shaken for 5 to 10 minutes and then allowed to stand at least 30 minutes prior to analysis. Aqueous samples were taken using a Hamilton syringe and transferred to the gas chromatograph (GC).

Analysis was by gas chromatograph (GC) with a hydrogen-flame ionization detecter (Beckman). The chromatographic column was 12 ft. x 0.25 in., stainless steel tubing packed with 25% SE 30 gum rubber on 30-60 mesh firebrick. Helium flow through the column was 65cc/min.

Aqueous samples were taken from the equilibration bottle through a septum in tubing at the base of the bottle using a Hamilton syringe and transferred to the GC. Aqueous phase concentrations of propylene were determined against a standard curve prepared from the gas sample used in the aqueous equilibration procedure

GLP compliance:

no

Remarks:

No data reported

Type of method:

other: Non-standard method

Key result

Water solubility:

38.5 mg/L

Temp.:

20 °C

pH:

7

Remarks on result:

other: pH not stated, therefore assumed standard

Details on results:

No further details provided

Conclusions:

Interpretation of results: slightly soluble (0.1-100 mg/L)

This study is well documented and meets basic scientific principles. It is unclear what effect the impurities might have had on the result and how the authors accounted for them in determining the solubility value. For this reason the study has been classified as reliable with restrictions. Solubility of n-pentane was reported as 38.5 mg/l at 20°C

Executive summary:

This study measured the solubilities of 65 hydrocarbons in water, at room temperature, by the direct injection of hydrocarbon-saturated water into a gas chromatograph. The concentration of hydrocarbon was determined by measuring the area under the chromatogram peak. The solubility of n-pentane was determined to be 38.5 mg/l at 20°C.

Reference 3

Endpoint:

water solubility

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

Up to 1966

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Predates implementation of GLP and development of standard guidelines but otherwise acceptable for assessment

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

Guideline:

other: Unknown if guideline was used for this study

Principles of method if other than guideline:

10 - 20 ml cyclopentane was added to 200 ml distilled water in a 250 ml glass bottle. Saturated solutions were prepared by stirring for a minimum of 24 h using a magnetic stirrer. The aqueous phase was examined for the presence of emulsion under a phase-contrast microscope with a magnification of 1700X - no emulsion was found. Temperature was 25 ± 1.5 ºC. Samples of cyclopentane saturated water were obtained either from beneath the hydrocarbon phase either by displacement of water through a tube, or by insertion of a hypodermic needle through a silicone rubber septum in a tubulation sealed near the bottom of the glass bottle. 50 μl sample was injected into the fractionator of the gas chromatograh (GC).

Analysis was by gas chromatograph (GC) with a hydrogen-flame ionization detecter (Beckman). The chromatographic column was 12 ft. x 0.25 in., stainless steel tubing packed with 25% SE 30 gum rubber on 30-60 mesh firebrick. Helium flow through the column was 65cc/min.

The concentration of hydrocarbon was determined by measuring the area under the chromatogram peak with a planimeter or an electronic integrator

GLP compliance:

no

Type of method:

other: measured using non-standard method

Key result

Water solubility:

156 mg/L

Temp.:

25 °C

pH:

7

Remarks on result:

other: pH not stated, therefore assumed standard

Details on results:

Not reported

Conclusions:

Interpretation of results: moderately soluble (100-1000 mg/L)

This study is well documented and meets basic scientific principles. It is unclear what effect the impurities might have had on the result and how the authors accounted for them in determining the solubility value. For this reason the study has been classified as reliable with restrictions. The water solubility of cyclopentane was determined to be 156 ± 9 mg/L.

Executive summary:

This study measured the solubilities of 65 hydrocarbons in water, at room temperature, by the direct injection of hydrocarbon-saturated water into a gas chromatograph. The concentration of hydrocarbon was determined by measuring the area under the chromatogram peak. The water solubility of cyclopentane was determined to be 156 ± 9 mg/L.

Description of key information

There is data available for this substance. Additionally, key data is available for structural analogues: Cyclopentane and Pentane. The data is read across to these substances based on analogue read across and a discussion and report on the read across strategy is provided as an attachment in IUCLID Section 13.

The water solubility of 2 -methylbutane is reported to be 47.8 -48.5 mg/L.

The water solubility of Cyclopentane is reported to be 156 mg/L.

The water solubility of Pentane is reported to be 38.5 mg/L.

Additional information

The information available is based on standard guidelines and peer reviewed handbook data, both considered reliable for assessment.