GB/T 16451-2017 English PDF (GBT16451-2017)

Delivery: 3 seconds. Download true-PDF + Invoice.
Get QUOTATION in 1-minute: Click GB/T 16451-2017
Historical versions: GB/T 16451-2017
Preview True-PDF (Reload/Scroll if blank)

GB/T 16451-2017: Natural fatty alcohols
GB/T 16451-2017
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 71.080.60
G 17
Replacing GB/T 16451-2008
Natural fatty alcohols
天然脂肪醇
ISSUED ON: DECEMBER 29, 2017
IMPLEMENTED ON: JULY 01, 2018
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of the People's Republic of China;
Standardization Administration of the People's Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Product classification ... 4
4 Requirements ... 5
5 Test methods ... 7
6 Inspection rules ... 21
7 Marks, packaging, transportation, storage ... 23
Natural fatty alcohols
1 Scope
This Standard specifies the product classification, requirements, test methods,
inspection rules and marks, packaging, transportation and storage for natural fatty
alcohols.
This Standard is applicable to a series of fatty primary alcohol products obtained from
natural vegetable oils and their derivatives through alcoholysis or hydrolysis,
esterification, hydrogenation and distillation.
2 Normative references
The following referenced documents are indispensable for the application of this
document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
GB/T 617, Chemical reagent -- General method for the determination of melting
range
GB/T 6682, Water for analytical laboratory use -- Specification and test methods
GB/T 7383-2007, Non-ionic surface active agents -- Determination of hydroxyl
value
GB/T 9282.1, Clear liquids -- Estimation of colour by the platinum-cobalt scale --
Part 1: Visual method
GB/T 11275, Surface active agents -- Determination of water content
QB/T 2739-2005, Preparations of standard volumetric solutions of general test
methods for washing products
3 Product classification
Natural fatty alcohols are divided into ten categories according to the carbon chain
length: C8~10 alcohols, C12~14 alcohols, C14~16 alcohols, C16~18 alcohols, C8 alcohols, C10
alcohols, C12 alcohols, C14 alcohols, C16 alcohols, and C18 alcohols. Their molecular
formulas and average relative molecular masses are shown in Table 1.
obtained under repeatability conditions shall not be greater than 0.4°C. The premise is
that the temperature above 0.4°C does not exceed 5%.
5.4 Color
5.4.1 Specimen processing
The solid fatty alcohol specimen needs to be heated to 75°C±5°C. After it is completely
melted, immediately pour it into a pre-warmed colorimetric tube. The liquid specimen
also needs to be kept above the melting point to make it transparent and clear, and then
placed in the colorimetric tube.
5.4.2 Determination
According to the provisions of GB/T 9282.1. The resulting platinum-cobalt color units
are expressed in Hazen.
Precision: The absolute difference between two independent determination results
obtained under repeatability conditions shall not be greater than 5 Hazen. The premise
is that the case of greater than 5 Hazen does not exceed 5%.
5.5 Acid value
NOTE: The number of milligrams of potassium hydroxide required to neutralize the acidity of 1 g
of fatty alcohol specimen is called the acid value.
5.5.1 Reagents
Reagents include:
a) Potassium hydroxide, c(KOH)=0.05mol/L ethanol standard titration solution,
prepared and calibrated according to 4.2 in QB/T 2739-2005;
b) 95% ethanol, neutralized with alkali until it is neutral to phenolphthalein;
c) Phenolphthalein, 10 g/L ethanol solution.
5.5.2 Instruments
Commonly used laboratory instruments and the following:
a) Burette without stopper: 10 mL; graduation is 0.02 mL;
b) Erlenmeyer flask: 250 mL.
5.5.3 Test procedures
Weigh about 10 g of specimen (accurate to 0.001 g) and place in a 250 mL conical flask.
Add 50 mL of neutral ethanol [5.5.1b)]. After heating to dissolve the specimen, add 2~3
V2 - the volume of hydrochloric acid standard titration solution consumed for specimen
titration, in milliliters (mL);
m2 - the mass of the specimen, in grams (g);
56.11 - the millimolar mass of potassium hydroxide, in milligrams per millimole
(mg/mmol).
Take the arithmetic mean of the two parallel determination results as the saponification
value of the specimen.
5.6.5 Precision
The absolute difference between two independent determination results obtained under
repeatability conditions shall not be greater than 0.2 mg/g. The premise is that the case
of greater than 0.2 mg/g does not exceed 5%.
5.7 Iodine value
NOTE: The number of grams of iodine absorbed per 100 g of fatty alcohol specimen is called iodine
value.
5.7.1 Reagents
Reagents include:
a) Carbon tetrachloride or chloroform;
b) Glacial acetic acid;
c) Iodine;
d) Potassium iodide: 100 g/L solution;
e) Sodium thiosulfate, c(Na2S2O3) = 0.1 mol/L standard titration solution: prepared
and calibrated according to 4.12 in QB/T 2739-2005;
f) Starch indicator solution, 10 g/L solution: prepared according to 5.3 in QB/T 2739-
2005;
g) Chlorine 98.8% or homemade: Add dropwise hydrochloric acid with a density of
1.19 g/L in potassium permanganate. The generated chlorine gas can be passed
into the iodine solution after being dried through the scrubber bottle filled with
sulfuric acid reagent (density is 1.84 g/L);
h) Iodine chloride, glacial acetic acid solution (Webster's
solution).
Dissolve 16.2 g of iodine chloride in 1000 mL of glacial acetic acid. Or prepare as
follows:
Weigh 13 g of iodine and dissolve it in 1000 mL of glacial acetic acid (it can be slightly
heated as needed when dissolving). Put in a 1000 mL brown reagent bottle. Cover with
a grinding stopper. After cooling, pour 100 mL ~ 200 mL into another brown bottle. Put
the cap plug in a dark place for adjusting Wechsler's solution. In the remaining 800 mL
~ 900 mL of iodine solution, pass through the chlorine gas that has been dried in the
concentrated sulfuric acid washing bottle until the solution gradually fades from dark
color until it is orange-red and transparent. Method for inspecting chlorine gas intake
and correction: Respectively sample 25 mL before and after chlorine gas flow. Add 20
mL of 15% potassium iodide solution [5.7.1d)] and 100 mL of water respectively. Use
sodium thiosulfate standard titration solution [5.7.1e)] to titrate. When the solution turns
light yellow, add 1 mL of starch indicator solution. Continue titration until the blue
color disappears as the end point. The volume of sodium thiosulfate standard titration
solution consumed after chlorine gas (Wechsler's solution) shall be nearly 2 times that
when chlorine gas is not passed. If it exceeds 2 times, the pre-reserved iodine solution
shall be added dropwise to adjust.
5.7.2 Instruments
Commonly used laboratory instruments and the following:
a) Iodine measuring bottle: 250 mL;
b) Pipette: 20 mL;
c) Graduated cylinder: 100 mL;
d) Unplugged burette (brown): 50 mL, with a division of 0.1 mL.
5.7.3 Test procedures
Accurately weigh 5 g of specimen (accurate to 0.001 g) in iodine bottle. Use a graduated
cylinder to add 20 mL of carbon tetrachloride or chloroform to dissolve. Accurately
pipette 20.0 mL of Wechsler's solution. Cork the bottle tightly. Add a small amount of
potassium iodide solution to seal. After shaking slowly, place in dark place at room
temperature for 60 min. Take out the iodine bottle. Add 25 mL of p...