-
2.2.2. DEGREE OF COLORATION OF LIQUIDS
2.2.2
溶液的色度
The examination
of the degree of coloration of liquids in the
range brown-yellow-red is carried
out
by one of the 2 methods below, as prescribed in
the monograph.
颜色在棕色
-
黄色
-
< br>红色范围之间的液体，其色度检查可根据个论中的规定，选择下述
2
种方
法中的一种来进行。
A solution is
colourless
if it has the appearance of
water R
or the solvent or is
not more intensely
coloured than
reference solution B9.
如果一种溶液的外观与水或指定的溶剂的外观一致，或者其颜色不深于棕色
9
号标准比色
溶液（
B9
）
，即可认为它就是无色的。
METHOD I
Using identical tubes of colourless,
transparent, neutral glass of 12 mm external
diameter,
compare 2.0 mL of the liquid
to be examined with 2.0 mL of
water R
or of the solvent or of the
reference solution (see Tables of
reference solutions) prescribed in the monograph.
Compare the
colours in diffused
daylight,viewing horizontally against a white
background.
方法
1
取外径为
12
毫米的无色、透明，中性玻璃相同试管
2
支，一支加
2.0ml
的供试液体，另一支
加
2.0ml
的水，或专论中所用的溶剂，或标
准比色溶液（参见对照溶液表）。在自然光下，
以白色为背景，比较两者的颜色。
METHOD
II
Using identical tubes of
colourless, transparent, neutral glass with a flat
base and an internal
diameter of 15 mm
to 25 mm, compare the liquid to be examined with
water R
or the solvent or
the reference solution (see Tables of
reference solutions) prescribed in the monograph,
the depth
of the layer being 40 mm.
Compare the colours in diffused daylight, viewing
vertically against a
white background.
方法
2
取
内径为
15mm
～
25mm
的无色、透明，中性玻璃平底试管
2
支，一支加供
试液体，另一支
加水，或专论中所用的溶剂，或标准比色溶液（参见对照溶液表）。液层
高度约为
40mm
。
在自然光下，以白
色为背景，比较两者的颜色。
REAGENTS
试剂与试液
Primary solutions
三基色溶液
Yellow solution
.
Dissolve 46 g of
ferric chloride R
in about 900 mL of a mixture of 25 mL
of
hydrochloric acid R
and
975 mL of
water R
and dilute
to 1000.0 mL with the same mixture.
Titrate and adjust the
solution to contain 45.0 mg of FeCl
3
·
6H
2
O per
millilitre by adding the
same acidic
mixture. Protect the solution from light.
黄色溶液的制备：取氯化铁
46g
，加
900ml
的盐酸溶液（
1
→
40
）使溶解，并用该盐酸溶液
稀释到
1000ml
。
滴定该溶液
，
并加适量盐酸溶液
（
1
→
40
）
进行调节，
使
FeCl
3
·
6H
2
O
的含量约为
45.0
mg/ml
。
将溶液避光保存。
Titration. Place in a 250 mL conical
flask fitted with a ground-glass stopper, 10.0 mL
of the
solution, 15 mL of
water R
,5 mL of
hydrochloric acid R
and 4 g
of
potassium iodide R
,close
the
flask, allow to stand in the dark
for 15 min and add 100 mL of
water
R
. Titrate the liberated
iodine with
0.1 M sodium
thiosulfate
, using 0.5 mL of
starch solution R
, added
towards the end
of the titration, as
indicator.
1 mL
of
0.1 M sodium thiosulfate
is equivalent to 27.03 mg of FeCl
3
·
6H
2
O.
滴定。取一个
250 mL
的带磨口玻璃瓶塞的锥形瓶，加入
10.0ml
该溶液，
15ml
水，
5ml
盐酸
和
4g
碘化钾，塞
紧瓶盖，在暗处放置
15min
，加
1
00ml
水，用硫代硫酸钠滴定液（
0.1mol/L
）
滴定析出的碘，在滴定近终点时加入
0.5m
l
淀粉指示剂，以蓝色消失为滴定终点。
每
1ml
的硫代硫酸钠溶液（
0.
1mol/L
）相当于
27.03mg
的
FeCl
3
·
6H
2
O
。
Red
solution
. Dissolve 60 g of
cobalt chloride R
in about
900 mL of a mixture of 25 mL of
hydrochloric acid R
and 975
mL of
water R
and dilute to
1000.0 mL with the same mixture.
Titrate and adjust the solution to
contain 59.5 mg of CoCl
2
·
6H
2
O per millilitre
by adding the
same acidic mixture.
红色溶液的制备：取氯化钴
60g<
/p>
，加
900ml
的盐酸溶液（
1
→
40
）使溶解，并用
该盐酸溶液
稀释到
1000ml
。
滴定该溶液，
并加适量盐酸溶液
（
1
→
40
）
进行调节，
使
CoCl
2
·
6H
2
O
的含
量约为
59.5 mg/ml
。
Titration. Place in a 250
mL conical flask fitted with a ground-glass
stopper, 5.0 mL of the
solution, 5 mL
of
dilute hydrogen peroxide solution R
and 10 mL of a 300 g/L solution of
sodium hydroxide R
. Boil
gently for 10 min, allow to cool and add 60 mL of
dilute sulfuric acid
R
and 2 g of
potassium iodide
R
. Close the flask and dissolve the
precipitate by shaking gently.
Titrate
the liberated iodine with
0.1 M sodium
thiosulfate
, using 0.5 mL of
starch solution R
,
added towards the end of the titration,
as indicator. The end-point is reached when the
solution
turns pink.
1 mL of
0.1 M sodium
thiosulfate
is equivalent to 23.79 mg
of CoCl
2
·
6H
2
O.
滴定。
取一个
250 mL
的带磨口玻璃瓶塞的锥形瓶，
加入
5.0ml
该溶液，
5ml
稀过氧化氢溶液，
10ml
的氢氧化钠溶液（
300 g/L
）
。缓缓煮沸
10
分钟，冷却并加
60 mL
稀硫酸和
2
g
碘化钾。塞
紧瓶盖，轻轻振摇使沉淀物溶解。用硫代硫酸钠滴
定液（
0.1mol/L
）滴定析出的碘，在滴
定近终点时加入
0.5ml
淀粉指示剂，以溶液呈现粉
红色时作为滴定终点。
每
1ml
的硫代硫酸钠溶液（
0.1mol/L
）相
当于
23.79mg
的
CoCl
2
·
6H
2
O
。
Blue primary solution
.
Dissolve 63 g of
copper sulfate R
in about 900 mL of a mixture of 25 mL
of
hydrochloric acid R
and 975 mL of
water R
and dilute to 1000.0 mL with the same
mixture.
Titrate and adjust the
solution to contain 62.4 mg of CuSO
4
·
5H
2
O per
millilitre by adding the
same acidic
mixture.
蓝色溶液的制备：取硫酸铜约
63g
，加
900ml
的
盐酸溶液（
1
→
40
< br>）使溶解，并用该盐酸溶
液稀释到
1000ml
。
滴定该溶液，并加适量盐酸溶液（
1
→
40
）进行调节，
使
CuSO
4
·
5H
2
O
的含
量约为
62.4
mg/ml
。
Titration. Place in a 250
mL conical flask fitted with a ground-glass
stopper, 10.0 mL of the
solution, 50 mL
of
water R
,12 mL of
dilute acetic acid R
and 3 g
of
potassium iodide
R
.Titrate
the liberated
iodine with
0.1 M sodium
thiosulfate
,using 0.5 mL of
starch solution R
, added
towards the end of the titration, as
indicator. The end-point is reached when the
solution shows a
slight pale brown
colour.
1 mL of
0.1 M sodium
thiosulfate
is equivalent to 24.97 mg
of CuSO
4
·
5H
2
O.
滴定。取一个
250 mL
的带磨口玻
璃瓶塞的锥形瓶，加入
10.0ml
该溶液，
< br>50ml
水，
12ml
稀醋
酸和
3g
碘化钾。
用硫代硫酸钠滴定液
（
0.1mol/L
）
滴定析出的碘，
在滴定近终点时加入
0.5ml
淀粉指示剂，以溶液呈现浅棕色时作为滴定终点。
每
1ml
的硫代硫酸钠溶液（
0.1mol/L
）相当于
24.97mg
的
CuSO
4
·<
/p>
5H
2
O
。
Standard
solutions
标准溶液
Using the 3 primary solutions, prepare
the 5 standard solutions as follows :
用上述三基色溶液，按下面表格规定的比例分别配制准溶液。
Table 2.2.2.-1
Volume in
millilitres
Standard solution
B (brown)
BY
(brownish-yellow)
Y
(yellow)
GY (greenish-
yellow)
R (red)
Yellow
solution
3.0
2.4
2.4
9.6
1.0
Red
solution
3.0
1.0
0.6
0.2
2.0
Blue
solution
2.4
0.4
0.0
0.2
0.0
Hydrochloric acid
（
10 g/L
HCl
）
1.6
6.2
7.0
0.0
7.0