(R*,R*)-1,4-dimercaptobutane-2,3-diol

Boiling point

Administrative data

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

30 January - 21 February 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method A.2 (Boiling Temperature)

Version / remarks:

EC No. 440/2008

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 103 (Boiling Point)

Version / remarks:

1995

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7220 (Boiling Point / Boiling Range)

Version / remarks:

1996

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Test material

Test material information

Constituent 1

Reference substance name:

(R*,R*)-1,4-dimercaptobutane-2,3-diol

EC Number:

222-468-7

EC Name:

(R*,R*)-1,4-dimercaptobutane-2,3-diol

Cas Number:

3483-12-3

Molecular formula:

C4H10O2S2

IUPAC Name:

1,4-disulfanylbutane-2,3-diol

Specific details on test material used for the study:

Batch No.: 44606300 / 50774
Storage Conditions: 2°C to 8°C, under nitrogen

Results and discussion

Boiling point

Key result

Boiling pt.:

>= 270 - <= 272 °C

Atm. press.:

1 013 hPa

Decomposition:

no

Any other information on results incl. tables

During the heating phase a distinct endothermic effect was observed in the temperature range of 40 – 60°C, which can be assigned to the melting of the test item.

The test item showed a second endothermic effect in the temperature range of approx. 250 – 320°C that can be assigned to the boiling of the test item, which was verified by the capillary method.

For the correction of the boiling temperature to standard pressure the test item was assigned to chemical group 8 (e.g. alcohols). A correction value f = 6.5 was used for the temperature of 270 °C.

The lowest measured onset temperature is corrected to the standard pressure to be 270.12°C and the highest onset temperature to be 272.28°C. As the corrected onset temperatures in both tests deviate by more than 0.5 K from their mean value of 271.20°C, the test item has a boiling range of 270 – 272°C.

Results of the DSC-measurement

No.	Sample weight/mg	Onset of Effect/°C	Range of Effect/°C	Weight loss/mg	Atmosperhic Presure/HPa
PN19051	8.91	42.28 271.83	40 – 60 (endo) 250 – 320 (endo)	8.91	1000.7
PN19053	8.35	42.60 269.71	40 – 60 (endo) 250 – 320 (endo)	8.34	1001.7

Optical verification using the capillary method

To verify the results of the DSC measurement, an additional measurement in a boiling capillary was performed in the temperature range of 200 °C to 320 °C with a heating rate of 10 K/min. During the heating phase up to the starting temperature the test item was melted at a temperature of approx. 60 °C and then further heated up to 200 °C with a heating rate of 10 K/min. At the starting temperature of 200 °C the test item was a clear, colourless liquid. Starting at a temperature of 210 °C a first formation of bubbles was observed, which increased its frequency at higher temperature. At a temperature of 300.3 °C the boiling criteria represented by the bubble rise frequency of 0.6 Hz was fulfilled. At this temperature the test item was still a clear, colourless liquid. The test was terminated at a maximum temperature of 320 °C.

According to the observations during the test in the capillary method, the second endothermic effect in the temperature range of 250 – 320 °C in the DSC measurements with open crucibles can be clearly assigned to the boiling of the test item. Due to this result, the onset temperatures of the DSC measurements are used for evaluation.

Applicant's summary and conclusion

Conclusions:

The test item 1,4-Dithiothreitol (CAS no. 3483-12-3) has a boiling range of 270 – 272°C at atmospheric pressure (1013 hPa) as determined by the differential scanning calorimetry and capillary method according to Regulation EC No 440/2008 Method A.2. and OECD Test Guideline 103 (1995).

Executive summary:

The test item1,4-Dithiothreitol (CAS no. 3483-12-3) has a boiling range of 270 – 272°C at atmospheric pressure (1013 hPa) as determined by the differential scanning calorimetry and capillary method according to Regulation EC No 440/2008 Method A.2. and OECD Test Guideline 103 (1995).