This product is 3,5-dichloro-2,6-dimethyl-4-hydroxy pyridine. According to the dry product, th
e content of c7h7cl2no should be 98.0-102.0%.
Character:
The product is a white or almost white powder, odorless.It is very slightly soluble in meth
anol or ethanol, insoluble in water, acetone, ether, or benzene, and slightly soluble in sodi
um hydroxide test solution.
Identification:
(1) take the solution under the content determination item and determine it by spectropho
tometry (SOP - 8021). It has the maximum absorption at the wavelength of 249nm and th
e minimum absorption at the wavelength of 235nm. The absorbance ratio at the wavelengt
h of 249nm and 235nm should be 1.50 ~ 1.58.
(2) The infrared absorption spectrum of the product should be consistent with that of the
control.
(3) Take about 50mg of this product, put it in a crucible, add 0.5g anhydrous sodium carb
onate, mix it, burn it at 600 ºC for 20 minutes, cool it down, add 10ml water, stir, and fil
ter, and the filtrate shows the identification reaction of chloride (SOP - 8023).
Inspection(alkalinity):
Take 0.10g of this product, add 5ml of 1mol / L sodium hydroxide solution, dissolve it by
slight heat, add 25ml of water, add dilute nitric acid to make it slightly acidic, filter, dilutet
he filtrate to 50ml with water, take 25ml, and check according to the law (SOP - 8014). C
ompared with the control solution made of 2.5ml of standard sodium chloride solution, it
should not be more concentrated (0.05%).
Chloropyridine
Related substances:
Take 0.10g of this product, put it into a 10ml volumetric flask, add about 5ml of methanol,
mix well, add 2ml of sodium hydroxide solution (1 → 50), put it into an ultrasonic bath t
o make it completely dissolved, add methanol to the scale, shake well, and take it as the
test solution; accurately measure an appropriate amount, dilute it with methanol to 0.10mg
solution per 1ml, and take it as the control solution. According to the test of thin layer c
hromatography (SOP - 8022), absorb 5 μ l of the test solution, point it on the silica gel g
f254 thin layer plate [pre develop with toluene methanol triethylamine (3:4:3), take it out
and air dry], develop with toluene methanol triethylamine (3:2:5) and air dry. Absorb 5 μ l
of the control solution, point it on the same thin plate, and then use toluene methanol t
riethylamine (3:4:3) as the developer. After development, dry it in the air, and inspect it u
nder ultraviolet light (254nm). If the test solution shows more than one impurity spot, it s
hall not be deeper than the main spot of the control solution (1.0%).
Weight loss on drying:
Take this product and dry it at 105 ºC to constant weight. The weight loss shall not excee
d 0.5% (SOP - 8011).
Moisture content:
Take 1.0g of burning residue and check it according to the law (SOP - 8013). The residue
should not exceed 0.3%.
Heavy metals:
The residue left under the item of ignition residue shall be inspected according to the law
(SOP - 8017, second method). The content of heavy metals shall not exceed 20 ppm.
Arsenic salt:
Take 1g of arsenic salt, add 1g of calcium hydroxide, mix, add a small amount of water, st
ir evenly, after drying, first use small fire to carbonize, then burn at 500 ~ 600 ºC to com
pletely ashing, cool, add 5ml of hydrochloric acid, 23ml of water to dissolve, according to t
he inspection (SOP - 8019), should meet the requirements (0.0002%).
Content determination:
Take about 0.15g of this product, accurately weigh it, put it into a 100ml flask, add 50ml
of methanol and 5ml of 0.5mol/l sodium hydroxide solution, shake it to dissolve, dilute it t
o the scale with methanol and shake it up; accurately measure 5ml, put it into a 50ml fla
sk, add 0.75ml of 0.5mol/l sodium hydroxide solution, dilute it to the scale with methanol
and shake it up; precisely measure 5ml, put it into a 50ml flask and dilute it to the scale
with methanol 0.1ml of 0.5mol/l sodium hydroxide solution was added to 50ml of methan
ol as blank control. According to the method of spectrophotometry (sop-8021), the absorba
nce was determined at 249nm. The absorbance coefficient of c7h7cl2no was calculated as
429.
Functions and uses:
Antigenic insect drugs. It is used for coccidiosis in poultry and rabbits.
Storage:
Keep out of light, airtight, and in a cool and dark place.
Retest period:
The first three months of validity
Validity:
2 years
Standard source:
Chinese Veterinary Medicine Dictionary (2015 Edition).
Packaging:
Audited Supplier 
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