SU940053A1 - Method of determination of naphtalene in honey - Google Patents

Description

(54). METHOD FOR DETERMINING NAFTALIN IN HONEY

one

The image refers to analytical chemistry, in particular to the methods of quantitative determination of naphthalene, for example, in the sanitary-hygienic sketch of metz.

A known method for the quantitative determination of naphthalene in a production unit, zaklk. which is in the spectrofluorimetric determination of this compound in the test product}.

However, this method cannot be used for the analysis of honey, since its implementation does not prevent the extraction and purification of naphthalene extracts from related substances.

The closest to the proposed technical essence to the achieved result is the method for determining (| talin and other aromatic hydrocarbons in solvents obtained from coal, which consists in processing the analyzed sample with hexane for 2 hours, followed by dividing the hydrocarbons into a column with

OXIDE aluminum and gas chromatographic definition 2.

This method of extraction of insufficient contact of the solvent with the exgrammable substance is not effective in the study of honey; it differs in the level and duration of the analysis (2.5 hours).

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

The goal is to achieve haem, that naphthalene is extracted from an aqueous solution of honey with a mixture of acetone and hexane in a ratio of 3-5: 1, and the extract is purified by silica gel for 2 to 5 minutes.

Claims (2)

For example. Liquid or crystallized meps, weighing 10 grams, dissolved in a separating funnel in 5 ml of distilled water, 25 ml of a mixture of acetone and hexane in a 4: 1 ratio are added and vigorously shaken for 5 minutes. After separation of the phases (10 min), the lower layer is discarded, and to the remaining acetone-hexane extract 3X4 gu, add 5a of 30 ml of water and again the sample is intensively shaken with 3 mn. 0.5 g of the force of the kagel, mix thoroughly for 3 minutes through the valve of the healing funnel, pour the purified extract into a conical evaporation vessel (you can prepare it from the filtering funnel by sealing the spout over the flame). The silica gel is washed with 2 ml of hexane, transferred to the same evaporation vessel, concentrated to 0.1 ml and analyzed on a Chrom 42 chromatograph with a detector, flame ionization under the following conditions: nitrogen flow through a column of 2 O ml / min, 30 ml of H 2 / min, air. ZOO ml / min; steel column (2.5 m X x 3 mm) with 10% polyelene glycol adipate deposited on Celite 545, silanized; trimethylchlorosilane, the temperature & heat of the evaporator, column and detector is 2 × 10, 16O, and cooTbej. 1 µl of the analyzed extract is injected into the chromatograph. The concentration of naphthalene in the studied samples was calculated according to the schedule of graphs and the height of the peak. The linearity of detection is in the range of 5 to 50 ng. The lower detection limit is 0.5-mg in 10 g of honey or 0.05 Mr / KrJ; §%. Under the above conditions, a glass column (2.5 mx es 3 mm) with 15% carbowax 2O M deposited on a chrotonon (0.16O-O, 20O mm) can be used for the hrenmat of naphthalene. It has been established that using a mixture of acetone and hexane as an extractant provides a good imitation of naphthalene .ti3 honey (8О, 2 + 1, О9%) and exclude. 3.. emulsion formation during the subsequent re-extraction of the test substance from the aqueous acetone extract with hexane. The proposed method of refining based on the different abilities of naphthalene and: co-extracting substances adsorbing on silica gel is simple, is carried out directly in the separating pin and ensures the complete release of the extract from related substances that interfere with the geo-chromatographic determination. Adsorption time plays a significant role in cleaning up the hexane extract. The optimal time for cleaning is from 2 to 5 minutes. With increasing time it can adsorb onto silica gel and naphthalene. The analysis time for one honey sample is. 40 min Claims of determination of naphthalene in honey, j, including extraction of naphthalene with hexane in an aqueous solution of honey, purification of the extract with silica gel, followed by gas chromatographic analysis,. characterized in that in order to increase the accuracy and speed up the process, the extraction is carried out with a mixture of hexane and acetone in a ratio of 1: 3-5, and the extract is cleaned with silica gel for 25 minutes. Sources of information taken into account in the examination I, Apae. , 1976, 48, No. 3, 524-528 ... 2.. Chem. 1977, 49, No. 3, p: 2253-226.