Registration Dossier

Administrative data

Endpoint:
boiling point
Type of information:
experimental study
Adequacy of study:
key study
Study period:
na
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
other: internal determination
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: MDSC guidelines
Version / remarks:
see attached doc
Principles of method if other than guideline:
The theory supporting modulated DSC can be easily understood by comparing it to conventional DSC. In conventional DSC, the difference in heat flow between a sample and an inert reference is measured as a function of time and temperature as both the sample and reference are subjected to a controlled environment of time, temperature, and pressure. The most common instrument design for making those DSC measurements is the heat flux design shown in Figure 1. In this design, a metallic disk (made of constantan alloy) is the primary means of heat transfer to and from the sample and reference. The sample, contained in a metal pan, and the reference (an empty pan) sit on raised platforms formed in the constantan disc. As heat is transferred through the disc, the differential heat flow to the sample and reference is measured by area thermocouples formed by the junction of the constantan disc and CHROMEL®* wafers which cover the underside of the platforms. These thermocouples are connected in series and measure the differential heat flow using the thermal equivalent of Ohm’s Law, , where = heat flow, ∆T = the temperature difference between reference and sample and RD = the thermal resistance of the constantan disc. CHROMEL®* and ALUMEL®* wires attached to the CHROMEL®* wafers form thermocouples which directly measure sample temperature. Purge gas is admitted to the sample chamber through an orifice in the heating block before entering the sample chamber. The result is a uniform, stable thermal environment which assures better baseline flatness and sensitivity (signal-to-noise) than alternative DSC designs. In conventional DSC, the temperature regime seen by the sample and reference is linear heating or cooling at rates from as fast as 100°C/minute to rates as slow as 0°C/minute (isothermal).
Modulated DSC is a technique which also measures the difference in heat flow between a sample and an inert reference as a function of time and temperature. In addition, the same “heat flux” cell design is used. However, in MDSC a different heating profile (temperature regime) is applied to the sample and reference. Specifically, a sinusoidal modulation (oscillation) is overlaid on the conventional linear heating or cooling ramp to yield a profile in which the average sample temperature continuously changes with time but not in a linear fashion. The solid line in Figure 2 shows the profile for a MDSC heating experiment. The net effect of imposing this more complex heating profile on the sample is the same as if two experiments were run simultaneously on the material - one experiment at the traditional linear (average) heating rate [dashed line in Figure 2] and one at a sinusoidal (instantaneous) heating rate [dashed-dot line in Figure 2]. The actual rates for these two simultaneous experiments is dependent on three operator-selectable variables:
GLP compliance:
no
Other quality assurance:
other:
Type of method:
other: MDSC

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid: viscous
Details on test material:
- Physical appearance: dark brown to black viscous liquid
- Storage conditions: in refrigerator (2-8°C) protected from light

Results and discussion

Boiling point
Key result
Boiling pt.:
ca. 177.5 °C
Atm. press.:
1 013 hPa
Decomposition:
no

Applicant's summary and conclusion

Conclusions:
the boiling point of cocoa shell extract is determined as
Executive summary:

boiling point accurately determined.