GB/T 14454.5-2008 PDF in English
GB/T 14454.5-2008 (GB/T14454.5-2008, GBT 14454.5-2008, GBT14454.5-2008)
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| GB/T 14454.5-2008 | English | 85 |
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Fragrance/Flavor substances -- Determination of optical rotation
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| GB/T 14454.5-1993 | English | 199 |
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Aromatics. Determination of optical rotation
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Standards related to (historical): GB/T 14454.5-2008
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GB/T 14454.5-2008: PDF in English (GBT 14454.5-2008) GB/T 14454.5-2008
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 71.100.60
Y 41
Replacing GB/T 14454.5-1993
Fragrance/Flavor substances -
Determination of optical rotation
(ISO 592:1998, Essential oils - Determination of optical rotation, MOD)
ISSUED ON: JULY 15, 2008
IMPLEMENTED ON: NOVEMBER 01, 2008
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of the People’s Republic of
China.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Terms and definitions ... 5
4 Reagents ... 6
5 Instruments ... 6
6 Operating procedures ... 7
7 Expression of results ... 8
8 Test report ... 8
Appendix A (Normative) Operating procedures of non-electronic polarimeters
... 10
Fragrance/Flavor substances -
Determination of optical rotation
1 Scope
This Part of GB/T 14454 specifies the method for determining the optical
rotation of fragrance/ flavor substances.
This Part applies to the determination of the optical rotation of fragrance/ flavor
substances. When the measured fragrance/ flavor substances are solid, semi-
solid, or very viscous and dark in color at room temperature, use a solution of
fragrance/ flavor substances to measure.
2 Normative references
The terms in the following documents become the terms of this Part by
reference to this Part of GB/T 14454. For dated references, all subsequent
amendments (not including errata content) or revisions do not apply to this Part.
However, parties to agreements that are based on this Part are encouraged to
study whether the latest versions of these documents can be used. For undated
references, the latest edition applies to this Part.
GB/T 14454.1, Fragrance/Flavor substances - Preparation of test samples
(GB/T 14454.1-2008, ISO 356:1996, MOD)
3 Terms and definitions
The following terms and definitions are applicable to this Part of GB/T 14454.
3.1 Optical rotation
Under the specified temperature conditions, when the polarized light whose
wavelength is 589.3 nm ± 0.3 nm (equivalent to the D line of the natrium
spectrum) passes through the fragrance whose thickness is 100 mm, the angle
of rotation of the polarized light vibration plane, which is expressed in
milliradians or degrees of angle.
Note: If it is measured at different thicknesses, the optical rotation shall be
converted to a value of a thickness of 100 mm.
3.2 Optical rotation in solution, so-called
Specific rotation
5.4 Thermometer, the measuring range is 10 °C ~ 30 °C; the division scale is
0.2 or 0.1 °C.
5.5 Constant temperature controller, it is used to control the temperature of the
sample at 20 °C ± 0.2 °C or other specified temperature.
6 Operating procedures
6.1 Sample preparation
If it is necessary, dry the sample, in accordance with the provisions of GB/T
14454.1.
When determining the specific rotation (see 3.2), the solution of the fragrance
product shall be prepared according to the concentration and solvent (4.2) that
are specified in the standards that are related to fragrance products.
6.2 Determination
Turn on the light source (5.2) and wait for it to reach full brightness.
If necessary, the temperature of the sample (6.1) can be adjusted to 20 °C ±
1 °C or other specified temperature1; then, inject the sample into the appropriate
polariscope tube (5.3) at the same temperature. Under constant temperature
control, start the water circulation; keep the polariscope tube at a specified
temperature (± 0.2 °C) during the test.
Fill the polariscope tube full of the sample; ensure that there are no bubbles in
the tube.
Put the polariscope tube into the polarimeter (5.1); read the right-handed (+) or
left-handed (-) optical rotation of the fragrance according to the scale on the
instrument.
6.3 Number of determinations
For the same sample, measure at least three times.
The difference of three measured values shall not be larger than 1.4 milliradians
(0.08 °). Take the average of the three readings as the measured result.
See Appendix A for the operating procedures of non-electronic polarimeters.
1 In general, the measurement shall be carried out at 20 °C. Exceptions are made in accordance with
the provisions in the relevant fragrance product standards.
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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