GB/T 14454.14-2008 English PDF (GBT14454.14-2008)

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GB/T 14454.14-2008: Fragrance/Flavor substances -- Preparation of standard solution, test solution and indicator solution
GB/T 14454.14-2008
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 71.100.60
Y 41
Replacing GB/T 14454.14-1993
Fragrance/Flavor substances - Preparation of
standard solution, test solution and indicator solution
ISSUED ON: JULY 15, 2008
IMPLEMENTED ON: DECEMBER 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 General provisions ... 5 
3 Preparation and calibration of standard solution ... 6 
4 Preparation of test solution ... 10 
5 Preparation of indicator solution ... 11 
Foreword
GB/T 14454, Fragrance/Flavor substances, consists of the following parts:
-- Part 1: Fragrance/Flavor substances - Preparation of test samples;
-- Part 2: Fragrance/Flavor substances - Method for valuation of odour;
-- Part 4: Fragrance/Flavor substances - Determination of refractive index;
-- Part 5: Fragrance/Flavor substances - Determination of optical rotation;
-- Part 6: Fragrance/Flavor substances - Quantitative evaluation of residue
on evaporation;
-- Part 7: Fragrance/Flavor substances - Determination of freezing point;
-- Part 11: Fragrance/Flavor substances - Determination of content of
phenols;
-- Part 12: Fragrance/Flavor substances - Method for determination of trace
chlorinated compounds;
-- Part 13: Fragrance/Flavor substances - Determination of carbonyl value
and carbonyl compounds content;
-- Part 14: Fragrance/Flavor substances - Preparation of standard solution,
test solution and indicator solution;
-- Part 15: Oil of sassafras - Determination of safrole and isosafrole content
- Gas chromatographic method on packed columns.
This Part is Part 14 of GB/T 14454.
This Part is a revision of GB/T 14454.14-1993 "Aromatics - Preparation of
standard solution, test solution and indicator solution". The technical content is
the same as GB/T 14454.14-1993; the compiling method is in accordance with
GB/T 1.1-2000.
This Part was proposed by China National Light Industry Council.
This Part shall be under the jurisdiction of National Technical Committee 257
on Fragrance and Flavor Cosmetic of Standardization Administration of China.
This Part is drafted by Shanghai Research Institute of Fragrance and Flavor
Industry.
The drafters of this Part: Jin Qizhang, Xu Yi, Cao Yi.
Fragrance/Flavor substances - Preparation of
standard solution, test solution and indicator solution
1 Scope
This Part of GB/T 14454 stipulates the preparation and calibration methods of
standard solution, test solution and indicator solution for fragrance titration
analysis.
This Part applies to the preparation of solutions of accurate concentration, as
well as the preparation of test solution and indicator solution.
2 General provisions
2.1 The water that is used in this Part of GB/T 14454 shall be distilled water or
water of equivalent purity unless other requirements are indicated.
2.2 The purity of the reagents that are used in this Part is at least analytically
pure.
2.3 Weights of the analytical balance, burettes, volumetric flasks, and pipettes
shall be regularly calibrated.
2.4 When calibrating the concentration of the standard solution, perform the
parallel test for not less than eight times; two persons shall do four parallels.
The extreme difference between the four parallel determination results per
person, and the ratio of the difference between the averages of the
determination results of the two persons to the average value cannot be greater
than 0.1% for the standard solution of 0.5 mol/L concentration, and cannot be
greater than 0.5% for the standard solution of 0.1 mol/L concentration (that is,
the difference of the fourth significant digit cannot be greater than 5).
2.5 The relative error between the concentration of the prepared standard
solution and the specified concentration cannot be greater than 5%.
2.6 The standard solution for titration analysis shall be calibrated and used at
normal temperature of 15 °C ~ 25 °C; the storage time cannot exceed three
months in general.
Where:
c(NaOH) -- the concentration of sodium hydroxide standard solution, in moles
per liter (mol/L);
m -- the mass of potassium hydrogen phthalate, in grams (g);
V1 -- the volume of sodium hydroxide standard solution for titration, in milliliters
(mL);
V2 -- the volume of sodium hydroxide standard solution for blank test, in
milliliters (mL);
0.2042 -- the mass of potassium hydrogen phthalate, in grams, that is
equivalent to 1.00 mL of sodium hydroxide standard solution.
3.2 Hydrochloric acid standard solution
c(HCl) = 0.5 mol/L, c(HCl) = 0.1 mol/L.
3.2.1 Preparation
Measure hydrochloric acid (relative density of 1.19) of the volume that is
specified in Table 3; inject it into 1 000 mL of water; shake well.
Table 3
3.2.2 Calibration
3.2.2.1 Determination method
Weigh standard anhydrous sodium carbonate, of the amount that is specified
in Table 4, that is burned to a constant mass at 270 °C ~ 300 °C; weigh to 0.000
2 g; place it in a 250 mL conical flask; use 50 mL of distilled water to dissolve;
add 10 drops of bromocresol green-methyl red mixed indicator solution; use the
prepared hydrochloric acid standard solution to titrate until the solution changes
from green to dark red; boil for 2 minutes; after cooling, continue to titrate until
the solution is dark red again. Do a blank test at the same time.
Table 4
Hydrochloric acid/ mL
Standard anhydrous sodium carbonate/g
solution; use the prepared potassium hydroxide ethanol solution to titrate until
the solution is pink.
3.4.2.2 Calculation
The concentration of potassium hydroxide ethanol standard solution is
calculated according to Formula (4):
Where:
c(KOH·C2H5OH) -- the concentration of potassium hydroxide ethanol standard
solution, in moles per liter (mol/L);
V1 -- the volume of hydrochloric acid standard solution, in milliliters (mL);
c1 -- the concentration of hydrochloric acid standard solution, in moles per liter
(mol/L);
V -- the volume of potassium hydroxide ethanol standard solution for titration,
in milliliters (mL).
4 Preparation of test solution
4.1 Refined ethanol (95%)
Add 1 g of silver nitrate (AgNO3) to every 1 000 mL of 95% ethanol for industrial
use; dissolve in 5 mL of water; mix thoroughly. Dissolve another 5 g of
potassium hydroxide in 25 mL of warm ethanol; after cooling, slowly add to the
above solution; reflux for 4 h; use it after distillation.
4.2 Neutral analytically pure ethanol or neutral refined ethanol (95%)
Take an appropriate amount of analytically pure ethanol or refined ethanol; heat
it; add a few drops of phenolphthalein indicator solution; use 0.1 mol/L sodium
hydroxide solution to neutralize while it is hot.
4.3 Potassium hydroxide ethanol solution (0.5 mol/L)
Dissolve 30 g of potassium hydroxide in 1 000 mL of 95% ethanol; let it stand
to clarify; carefully pour the upper transparent solution; or filter and store in a
glass bottle. The solution cannot be used if it appears yellowish.
4.4 Hydroxylamine solution