SU979992A1 - Method of determination of naphthalene in indene coumarone resins - Google Patents

Description

(54) METHOD FOR DETERMINING NAFTALIN IN INDENCUMARON RESINS

This invention relates to analytical chemistry, in particular to methods for determining naphthalene in indenomeric new resins. A known method for the determination of naphthine and its derivatives in a solution of benzene by gas-liquid chromatography on packed columns. The disadvantage of this method is its inapplicability to the analysis of indene marmaron resins, which are removed from the chromatographic column. The closest in technical essence and the achieved result to the invention is the method of determining naphthalene in indene marmarone resins by dissolving the resin in the ash, precipitating it with methanol, filtering the precipitate rectification of the filter with separation of the naphthalene fraction (190-2 + 5 ° С) subsequent analysis by the method of cryoscopy 2. The disadvantage of this method is the low accuracy due to the loss of naphthalene during rectification (relative error t 5%). The purpose of the invention is to improve the accuracy of the method. The goal is achieved in that according to the method for determining naphthalene in indene marmarone resins by dissolving the analyte in benzene, adding precipitator, filtering the precipitate formed, n-heptane is used as a precipitant at a volume ratio of benzene and n-heptane, 5 and the resulting filtrate is subjected to a gas chromatographic analysis . Under these conditions, naphthalene, indene, coumarone, styrene and other low-boiling hydrocarbons are dissolved and multi-core aromatic carbohydrate-9Pods do not dissolve and are hymemers. Tl p and me 1. .5 g of indenmonone resin is ground, benzene is added

in an amount of 10 ml, dissolved with shaking. Then 40 ml of β-heptane are added. The mixture is stirred and allowed to stand. After filtration, 0.7-0.8 g of silica gel is added to the filtrate, stirred, allowed to stand for 10 minutes. The settled solution in the amount of 5 ml is transferred to the penicillin vial, 0.020, 025 g of acetophenone (internal standard) is added with an accuracy of 0.0001 g, agitated, and chromatography is carried out.

Conditions for determination of free aromatic hydrocarbons on the chromatograph CL-69: detector - katharometer; 3m column; solid carrier - hezasorb - AW NMD, fraction O, mm; stationary phase - reopleks-400; the amount of stationary phase in relation to the solid carrier gas carrier is helium; carrier gas velocity 30 ml / min; column temperature 200-295 ° C; evaporator temperature 200 С; the pressure of the carrier gas at the inlet to the column 3 kgf / cm; detector current mA; belt speed 600 mm / h; sensitivity 1; sample amount 5 μl.

The content of naphthalene on an anhydrous sample is calculated by the formula L - K-RO-IN-50-100-100

- - .h.-cioo-B

where X is the naphthalene content in the sample, wt.%;

K — correction factor (determined from parallel analyzes of five artificial mixtures of naphthalene and acetophenone dissolved in heptane) is 1, 29;

PC, - acetophenone weights, 2;

h is the peak height of naphthalene, mm;

Example 5: Determine the amount of alcohol. After settling the precipitate, the patronymic of naphthalene is separated from the solution by filtration. sobu. 500 g of resin are dissolved in 950 ml. Filtrate is loaded into a flask and rekten enzol and 3.5 liters of methyl is precipitated. The separation in the range of 190 DPR is the weight of the initial sample, g; Cd is the peak height of acetophenone, mm; B - water content, wt.% (Determined according to GOST 77-65 with the addition according to p. 3.b. OST 1-30-77 per indencumin resin).

Found in two parallel determinations of 11.3 and 12.2 naphthalene, respectively. Relative error tk, Q%.

In tab. 1 shows the results of experiments on the determination of naphthalene using the additive method.

Table 1

EXAMPLE 2 The conditions are similar to those described in Example 1. 30 ml of H-heptane are added, the precipitate is separated, dried, weighed and the weight of the precipitate is found. The amount of solutes is determined chromatographically and, by subtracting the amount and amount of solutes from 5 g, the loss of the resin is found (Table 2).

ExampleZi4. The conditions of the analysis are similar to those described in examples 1 and 2. lO and 50 ml of n-heptane are added (Table 2).

In tab. Figure 2 shows the effect of the amount of N-heptane on the solubility of the indene marmaron resin.

Table 2

5979992 "

. Crypto-H-heptane naphthalene is determined at a volume ratio of

by the picnic method of benzene and n-heptane 1: "-, 5, and the half formula of the invention by means of a matographic analysis.

Method for determination of naphthalene in intakes taken into account in the examination of denmarmarone resins by solution Gas horrone analyte in ben-matografi as a method of research

ashes, adding precipitator, filter oil. M. i Science, 1973, p. 142. The formation of a precipitate,. 2. Gluzman LD, Edelman I.I.

characterized in that the laboratory control of coke-chemical aiming to increase the accuracy of the method of production, M., Metallurgists,

1968 is used as precipitator. (prototype). chenny filtrate is subjected to gasohro5 Sources of information

Claims (1)

Claim A method for determining naphthalene in indencumarone resins by dissolving the analyte in benzene, adding a precipitant, filtering off the precipitate formed. characterized in that, in order to improve the accuracy of the method, use as a precipitant N-heptane with a volume ratio of benzene and n-heptane of 1: 4-4.5 and the obtained filtrate is subjected to gas chromatographic analysis.