SU1448275A1 - Method of quantitative analysis of m-phenylene bismaleinimide - Google Patents

Abstract

The invention relates to analytical chemistry, in particular, a method for the quantitative determination of m-phenylene di bismadeine imide. The goal is to increase the sensitivity and accuracy of the determination. Anapis are treated with a sample with concentrated nitric acid, followed by measuring the intensity of the fluorescence that occurs. The method allows to increase the detection sensitivity from 10 -5 Yu to 4.2-4.5-10 mol / L and its accuracy from 1.5-20 to 5%. 4 tab.

Description

four

four

00

IND ate

This invention relates to an improved method for the quantitative determination of m-phenylene bismaleimide and may be used in analytical chemistry.

The purpose of the invention is to increase the sensitivity and accuracy of the determination.

Example 1. Determination of m-phenylene bismaleimide (m-FBMI) in the control sample.

The test solution in an amount of 0.5 ml with a concentration of 0.04 mg / ml is introduced into a 25 ml volumetric flask, 5 ml of concentrated nitric acid (d 1.380 g / cm) is added, brought to the mark with purified dioxia, stirred and incubated 24 After that, a part of the solution is placed in a 1 cm thick cuvette and the mixing intensity is measured on a Quantum laboratory fluorometer at an excitation wavelength and a fluorescence wavelength of 500 nm.

The results of the analysis of control samples m-FBMI are given in table, 1.

th

14482752

by the order of magnitude. U - 5-10 mol / l, the accuracy of determination is 15-20%. The proposed method has a sensitivity of 4.2 - 4.5 - 10 mol / l, the accuracy of determination is 5%.

Table 1

Example 2. Determination of the degree of conversion of the monomer m-FBMI polymer.

At different stages of polymerization, the sample is crushed and filled with purified dioxane. The unpolymerized m-FBMI is thus dissolved in dioxane. Further definition as in example 1.

The excitation spectrum of m-PFMI is in the region of 290-450 nm with an excitation maximum at 416 nm. The m-FBMI fluorescence spectrum is in the region of 450-600 nm with a maximum at 500 nm.

The calibration curve is plotted in terms of luminescence intensity (%) m-FBMI depending on its concentration (mg / ml) with the optimum amount of nitric acid determined experimentally (.2)

The initial data for plotting are given in table 3.

The results of measurements of fluorescence intensity versus time after the addition of nitric acid are given in.

From the measured fluorescence intensity (luminescence) from the calibration curve, the unknown concentration of m-FBMI is determined.

The well-known photometric method for determining m-FBMI has

Table 2

Dependence of the luminescence intensity of m-phenylene bismaleimide on the amount of reagent (concentrated nitric acid)

Table3

The dependence of the intensity of luminescence on the concentration of m-phenylene bis-maleimide

Forms of y, l and inventions 25 that, in order to increase the sensitivity and accuracy of determination, the concentration of m-phenylene bismaleimine imide by nitric acid is used in the method of quantitative determination of the reagent and after

processing of the analyzed reagent sample; measure the intensity of the volume that differs in that 30 fluorescence occurs.

The dependence of intensity (J "yopec- tentsii m-FBMI from time

Claims (1)

Claim A method for the quantitative determination of m-phenylenebismaleiminimide by processing the analyzed sample with a reagent, characterized in that 25 that, in order to increase the sensitivity and accuracy of determination, concentrated nitric acid is used as a reagent, and after treatment, the intensity of the resulting fluorescence is measured.