1) Qualitative inspection
Add 1 drop of 10% ferric chloride solution to the aqueous solution of the sample to turn purple
5g sample (accurately to 0.
0002g), place it in a 150mL Erlenmeyer flask, and add 13mL 95% ethanol
After dissolving, add 12 mL of water, add 3 drops of phenolphthalein indicator, and use 0.
1 mol/L NaOH standard solution to drip until the solution is reddish for 30 seconds, which is the end point
At the same time do a blank experiment
Where: V 1 ——The volume of NaOH consumed by the titration sample, mL;
V 2 ——The volume of NaOH consumed in the blank experiment, mL;
c——The molar concentration of NaOH standard solution, mol/L;
m——the mass of the sample, g
3) Determination of free phenol
5mol/L NaOH standard solution; NH 3 -NH 4 Cl buffer solution: 20g NH 4 C1 dissolved in 200mL water, add 72mL ammonia and dilute to 1000mL with water; 8% potassium ferricyanide solution; 2% 4-aminoantibiotic Billing solution (use period 7d); phenol standard solution: 0.
5g phenol (accurate to 0.
0002g) dissolved in water, dilute to 500mL, shake well, then accurately draw 10mL, dilute to the mark in a 100mL volumetric flask, shake well, Equipped when used
Standard colorimetric tube preparation: accurately weigh 0.
1000g of salicylic acid without phenol , add 2mL ethanol to dissolve it in a 25mL colorimetric tube , add 1.
5mol/L NaOH standard solution, and add several milliliters of phenol standard solution , And then process the same with the sample at the same time (see next paragraph)
1000g sample (accurately to 0.
0001g) in a 25mL colorimetric tube, add 2mL ethanol, then add 1.
5mol/L NaOH standard solution, 2mL NH 3 -NH 4 C1 buffer solution
Then dilute with an appropriate amount of water to the same volume as the standard colorimetric tube, and add 10 drops of 2% 4-aminoantipyrine solution
After shaking, add 5 drops of 8% potassium ferricyanide solution
Shake well again, compare the displayed color with the standard tube, and record the number of milliliters of the phenol standard solution contained in the standard colorimetric tube with the same color as the sample solution
Where: V——Volume of phenol standard solution in standard colorimetric tube, mL;
m——the mass of the sample, g
This product has a wide range of applications in the pharmaceutical synthesis industry, dye industry, and food industry
In the pharmaceutical industry, drug itself is used as disinfectant antiseptic for topical skin hyperplasia and skin fungal infections; as pharmaceutical intermediates for the production of killer on, vasopressin, acetylated aspirin, sodium salicylate, salicylamide , pargyline Drugs such as sugar, niclosamide, phenyl salicylate, ethyl p-hydroxybenzoate, and bismuth subsalicylate
In the dye industry, it is used to produce direct yellow GR, direct light fast gray BL, direct light brown RT, acid mordant brown G, acid mordant yellow GG and other dyes
Various esters of salicylic acid can be used as fragrances, such as daily fragrances and other blended fragrances
In the rubber industry, it is used to produce anti-scorching agents, ultraviolet absorbers and foaming aids
Salicylic acid can also be used a phenolic resin curing agent, anodically coloring agents, preservatives textile pulp, bulking agents (accelerating agent) or the like when the fiber cooperation
(1) This product stimulates the skin and mucous membranes, has a corrosive effect, and its toxicity is lower than that of phenol.
Operators should wear labor protection equipment
(2) Packed in woven bags lined with plastic bags, protected from light and moisture, stored in a cool, ventilated place, and stored separately from oxides and explosives
Related links: Product performance and technical formula of salicylic acid