SU1503003A1 - Method of quantitative analysis of sodium-carboxymethyl cellulose - Google Patents

Abstract

This invention relates to the analytical chemistry of cellulose derivatives and makes it possible to simplify and accelerate (from 9 to 1 pm) the determination of sodium carboxymethyl cellulose in household chemicals. This is achieved by precipitating it from a solution of the analyzed mixture with molybdenum phosphoric acid, taken in excess, in the presence of barium chloride and by potentiometric titration of unreacted molybdenum phosphoric acid in the liquid phase with a solution of diantipyrylmethane. 8 tab.

Description

This invention relates to the analytical chemistry of cellulose derivatives and can be used to analyze household chemical goods.

The purpose of the invention is to simplify and speed up the analysis.

Example 1. Determination of sodium carboxymethylcellulose (On - CODE) in the aniton coupling agent.

The product contains various interchangeable dyes (yellow, blue, pink). In the example, the determination was carried out in the presence of a dispersed pink dye.

A factor that interferes with the determination of Na-CMC in compositions is the presence of non-surfactant in them, which also form complexes with tetro-polyacids, in particular g of molybdenum phosphoric acid. However, this is the case of 11-11; its action is easily eliminated if you use the ability of Na-CMC to salve out alcoholic solutions. Non-ionic surfactants dissolve well in alcohol. The introduction of the salting out stage does not exacerbate the complexity of the technique.

A calibration curve is plotted for the volume of molybdenum phosphoric acid (fFK) versus the volume of diantipyrylmethane (DAM).

In glasses with a capacity of 50 cm, 5 cm of a solution of 0.5 mol / dm of hydrochloric acid, 18 cm of ethanol are introduced in each case, successively 1.0j 1.5; 2.0; 2.5; 3.0 cm of an IFC solution with a concentration of 0.01 mol / dm and 5.0; 4.5; 4.0; 3.5; 3.0 cm of water, respectively.

In tab. 1 shows the composition means Aniton.

SP

about with

O9

31503003

T l b i c a 1

Place the cups on a magnetic stirrer and potentiometrically titrate with vigorous stirring with a DAM solution with a concentration of 0.03 mol / dm at a polarization current density on the platinum electrode of 10 μA / cm. Titration is carried out on a pH-340 pH meter or EV-7A ionomer with platinum (EPV-1) and chlorine-silver (EVL-1MZ) electrodes. Near the equivalence point, the titrant is added in portions of 0.02 cm. The equivalence point is determined from the largest potential jump observed from the addition of equal volumes of titrant.

The data for the construction of the calibration graph of the dependence of the volume of the IFC on the volume of DAM are presented in Table. 2

Table 2

To 1.6310 g of the anitizing agent ANITON, containing 4.5% Na-CMC, pour 15 cm of hot ethyl alcohol in a cup, mix it with a glass rod, try to break the coagulated Na-KMU into small pieces, decant through a glass filter. Then the precipitate is again washed with 10 cm of hot alcohol and decanted through the same filter. The sediment in the cup is dissolved

five

0 5 0

five

0

five

,

boil with water and transfer quantitatively to a 100 cm volumetric flask. The glass filter is also rinsed with hot water, draining it into the same flask. The total amount of water in the flask is 35 cm. The contents are thoroughly dissolved. Then the solution is cooled, 10 cm of a 10% aqueous solution of barium chloride are added and 15 cm of Solution K to a concentration of 0.01 mol / dm is added dropwise from a burette. A precipitate falls. The contents of the flask are made up to the mark with distilled water, mixed and filtered through a filter paper. 10 cm of the filtrate are placed in a 50 cm beaker, 18 cm of ethanol, 2.5 cm of 1 mol / dm hydrochloric acid solution are added and titrated with potentiometric diantipyrylmethane with a concentration of 0.03 mol / dm as described in the construction of the calibration characteristic.

0.96 cm of DAM solution was consumed for titration, which corresponds to 1.02 cm of solution M) K (V / 1.02 cm).

A standard solution of sodium carboxymethylcellulose brand 70/300 containing 0.0025 g of Na-CMC in 1 cm is prepared. 20 cm of the standard solution, which corresponds to 0.05 g of Na-CMC, is pipetted into a 100-cm volumetric flask and determined in the same way as when analyzing the coupling agent by Anita.

For titration consumed 1.10 cm of DAM solution, which corresponds to 1.17 cm of solution (Vp 1.17 cm).

The percentage of Na-CMC (X) in percent is calculated by the formula

() (15 - Vg) 10) .m

   3 (15, 17 "MOT) 1.63

4, A6% Na-CMC in an Aniton coupling agent was determined. The analysis time is 60 min.

PRI mme R 2. Determination of Na-CMC in a coupling agent Aniton in a known manner.

To 13.6498 g of the anething agent Aniton, containing 4.5%, in a glass pour 50 cm of ethanol. Stir with a glass rod, try to break

coagulated Na-CMC into small cuijOKH. Decanted through a glass filter. The precipitate is then washed twice with 25 cm of hot ethyl alcohol and decanted through the same filter. The precipitate in the glass is dissolved in 100 cm of distilled water. To accelerate dissolution, the solution is heated to

C for 30 minutes on a water bath with agitation. The solution is painted

80 not

solution of acetic acid, 15 g of potassium iodide and placed in a dark place.

After 10 minutes, the iodine given up is titrated with 0.1 n. sodium thiosulfate solution in the presence of starch as an indicator. 11.2 cm of sodium thiosulfate was consumed for the titration.

Mass fraction of copper (X,) in percents.

in pink color. The resulting Na-KM1D solution is cooled, pH meter electrodes are introduced into it and added in small portions with thorough stirring with a glass rod of 1N. solution of sulfuric acid to pH 2.2. Acidic solution from a burette is poured with stirring 25 cm of copper sulphate solution with a concentration of 0.1N, and then a 5% solution of ammonia to pH 4.0. Then remove the electrodes from the solution and wash them with distilled water. The precipitate of the copper salt of carboxymethylcellulose is thoroughly washed. For this purpose, it is preheated in a glass in a water bath to 60 ° C. After settling the carboxymethylcellulose copper salt, the thief is decanted through a double filter paper on a Buchner funnel under a slight vacuum. The precipitate in the glass is rubbed with a stick and washed 3 times with 30% ethanol solution

where 162 is the molecular weight of the elementary unit of the cellulose macromolecule; 35 0,888 - increase molecular

the masses of this link when the group is introduced into it (-CHjCOO Cu;

X is the mass fraction of copper in the copper salt of carboxymethylcellulose,%;

31.77 — gr-equivalent of copper in reaction with carboxymethylcellulose.

40

100 cm each, after which the precipitate is transferred to a filter and washed twice with 50 cm of a 94% ethyl alcohol solution. The completeness of the washing is checked by the absence of ions in the sample of the washing liquid by reaction with barium chloride.

Then, the sediment is removed from the filter with a glass rod, try not to grab the filter fibers, transfer it to a suspended weighing bottle and dry for 1 hour to constant weight at 150 C. Determine the degree of substitution by carboxymethyl groups.

To do this, the carboxymethylcellulose copper salt, dried to POSTANJQ, the filtrate and the washing liquid from the BOTTOM mass is transferred to a 250 cm conical flask (t 0.5923 g), until

31.77 - 0.888-12.02

The mass fraction of Na-CMC is determined.

with a tube quantitatively transferred into a 750 cm conical flask, add 5 cm 6 n. a solution of acetic acid, 10 g of potassium iodide and iodine which is liberated is titrated with 0.1 n. sodium thiosulfate solution in the presence of starch. 12.9 cm of sodium thiosulfate was consumed for the titration.

Bavly 4 cm 94% ethanol, 100 cm distilled water and 8 cm 5% ammonia solution. The resulting copper ammonium is destroyed by adding 6 n. acetic acid solution until the color of the solution changes, and then another 5 cm 6 n is added.

max is calculated by the formula

V V.0.006357-100 liters - --- l

 m

where V is the volume exactly O, 1 n. sodium thiosulfate solution, after titration, cm; m is the mass of the carboxymethylcellulose copper salt, g;

0.006357 is the amount of copper corresponding to 1 cm of exactly 0.1 n. sodium thiosulfate solution,

Y.006357Ч00. ,,, „0.59231.0.

The degree of substitution (f-) is calculated

according to the formula

 ST, 0.888 x7

162 is the molecular weight of the elementary unit of the cellulose macromolecule; 0.888 - Molecular Magnification

the masses of this link when the group is introduced into it (-CHjCOO Cu;

X is the mass fraction of copper in the copper salt of carboxymethylcellulose,%;

31.77 — gr-equivalent of copper in reaction with carboxymethylcellulose.

Exit and wash liquid from COL

but

31.77 - 0.888-12.02

The mass fraction of Na-CMC is determined.

The filtrate and wash liquid from QOL-

with a tube quantitatively transferred into a 750 cm conical flask, add 5 cm 6 n. a solution of acetic acid, 10 g of potassium iodide and iodine which is liberated is titrated with 0.1 n. sodium thiosulfate solution in the presence of starch. 12.9 cm of sodium thiosulfate was consumed for the titration.

The mass fraction of Na-CMC (X,) as a percentage is calculated by the formula

L-100

W (V, - V,)

x - de v, - obg, eat exactly 0.1 and. solution

copper sulfate, cm; Vg is a volume of exactly 0.1 n. sodium thiosulfate solution, followed by titration, cm; m is the weight of the agent Aniton, - A is the amount of sodium carboxymethylcellulose corresponding to 1 cm exactly 0.1 n. sodium thiosulfate solution, g, which is calculated by the formula

2 (162. 80--)

T5- °°°

ten

, 0.016,

162 is the molecular weight of the elementary unit of the cellulose macromolecule;

80 is an increase in the molecular mass of 25 of this link with the introduction of Example 3, (1) the projection of sodium carboxymethylcellulose in Elga hand deodorant.

In tab. 4 shows the composition of the deodorant for Elga hands.

T a b l and c a 4

Low flake fraction of mink grease Sodium carboxymethylcellulose brand 70/450 Formalin Ethyl alcohol Acid mass Fragrance Glory Drinking water

deniyu group CHjCOONa;

G degree of substitution by carboximethyl groups

Z is the conversion factor introduced due to the fact that the equivalent of copper when interacting with iodine is 2 times greater than when interacting with carboxymethylcellulose.

BUT

92.30

+ 0.016 0.0511;

.. (25 - 12.9) -0.0511.100. „Xj T376498

4.53% of Na-CMC in the Aniton coupling agent was determined. Analysis duration 9 hours

In tab. Figure 3 shows the results of the determination of Na-CMC in the Aniton coupling agent according to the proposed and known methods.

Table.3

0

five

0

five

1.6499 g of Elga deodorant containing 3% Na-CMC is dissolved in 25 cm of hot water and transferred to a 100 cm volumetric flask. The contents of the flask are cooled, to & 10 cm of a 10% aqueous solution of barium chloride and a 15 cm solution of an IFC concentration of 0.01 mol / dm from a burette 15 cm dropwise. A yellowish, flocculent precipitate falls out. The contents of the flask are made up to the mark with distilled water, mixed and filtered through a filter paper. 10 cm of the filtrate are placed in a 50 cm beaker, 18 cm of ethanol are added, 2.5 cm of 1 mol / dm hydrochloric acid solution and titrated with potentiometric solution of dantipyrylmethane with 0.03 mol / dm potentiometric solution

construction of the calibration characteristic.

15

1.18 cm of dantipyrylmethane was consumed for titration, which corresponds to 1.26 cm of an IFC solution (V, 1.26 cm).

A standard solution of sodium carboxymethyl cellulose, mark 70/450 Oh, containing 0.0025 g of Na-CMC in 1 cm is prepared. 20 cm of the standard solution, which corresponds to 0.05 g of Na-CMC, are transferred to a 100-cm volumetric flask and are determined in the same way as in the analysis of the Elga deodorant. 1.18 cm of DAM was consumed for titration, which corresponds to 1.26 cm of IFA solution (V 1.26 cm).

3.00 3.05 0.13 3.05 ± 0.14 3.23 0.31 3.23 ± 0.32

. PRI me R 4. Determination of sodium carboxymethylcellulose in the ameliel agent.

The composition of the funds Amelie are given in table. 6

Table

To 1.8327 g of Ameli coupling agent containing 3% Na-CMC, at 3

1 o

The mass fraction of Na-CMC (X) in percent is calculated by the formula

20- (15 - V. -10) - 100

X

Vf

(5 - V, j 10) -t

 2i0025 2g {5; lj 26il0 llpg. P1 (15 - 1.2b710) -176499

Defined 3.03% in Elga deodorant. Duration ana-. LISA 40 min.

In tab. 5 gives the content of Na-CMC in Elga hand deodorizer, determined according to the proposed and known methods.

T a b l and c a 5

15 cm of hot ethyl alcohol is poured into a cup, stirred with a glass rod, try to break the coagulated Na-CMC into small

The pieces are decanted through a glass filter. Then the precipitate is again washed with 10 cm of hot alcohol and decanted through the same filter. The precipitate is dissolved in a cup heated to

boil with water and quantitatively transfer to a 100 cm volumetric flask. The glass filter is also rinsed with hot water, draining it into the same flask. Total water in

the flask should be 30-35 cm. The contents of the flask are thoroughly dissolved. Then the solution is cooled, 10 cm of a 10% aqueous solution of barium chloride is added and 15 cm of an IFC solution is added dropwise from a burette.

concentration of 0.01 mol / dm. A precipitate falls. The contents of the flask are brought to the mark with distilled water, moved and filtered through a filter paper. 10 cm of filtrate is placed in

glass with a capacity of 50 cm, 18 cm of ethanol, 2.5 cm of 1 mol / dm solution of hydrochloric acid are added and titrated potentiometrically with a solution of diantipyrylmrtam concentration

0.03 mol / dm, as described in the construction of the calibration characteristics.

1.02 cm of DAM solution was consumed for titration, which corresponds to 1.08 cm of №K solution (V

1.08 cm).

 f

Prepare a standard, 70/450 sodium carboxymethyl cellulose solution containing 0.0025 g of Na-CMC in 1 cm; 20 cm of the standard solution, which corresponds to 0.05 g of Na-CMC, and transfer them with a pipette to a 100 ml volumetric flask. see and carry out the determination in the same way as in the analysis of the ameliy agent.

1.09 cm of DAM solution was spent on titration of DAM, which corresponds to 1.16 cm of IFC solution (V

By 1.7846, 1-deodorant, Florant, containing about 3Z, is poured into a glass of 15 cm of hot ethyl alcohol, shredded with a glass rod, try to divide the coagulated Ma-K # 1 into me. 1 pieces, decant sph k.p nny filter.

Then the precipitate is again washed with 10 cm of hot alcohol and decanted through the same filter. The precipitate in the cup is dissolved with water heated to boiling and transferred quantitatively to a 100 cm volumetric flask. The glass filter is also rinsed with hot water, draining it into the same flask. About- The total volume of water in the flask is 30 cm. The contents of the flask are thoroughly dissolved. Then the solution is cooled, 10 cm of a 10% barium chloride solution is added and a 0.01 mol / dm concentration is added dropwise from a 15 cm buret. A precipitate falls. The contents of the flask are made up to the mark with distilled water, mixed and filtered through a filter paper. 10 cm of filtrate are placed in a glass alongside55

(15 - 1.18-10) 1.7846

2.89% of Na-CMC in Florant deodorant was determined. The analysis time is 60 min.

In tab. 8 shows the results of the determination of Na-CMC in the composition of household chemical goods.

Claims (1)

Invention Formula The method of quantitative determination of sodium carboxymethyl cellulose by precipitating it from a solution of the analyzed mixture with a reagent taken in excess, followed by separation of the liquid phase and titration of unreacted reagent in it, in order to simplify and speed up the process, as a reagent molybdenum phosphoric acid is used in the presence of barium chloride, and the titration is carried out using a potentimetrically solution of diantipyrylmethane.